03-22-21 Work Session Agenda and MaterialsCITY COUNCIL
KCITY OF WORK SESSION AGENDA
ALISPELL March 22, 2021, at 7:00 p.m.
This meeting will occur with Council and staff present in Council Chambers with social
distancing in place, as well as via video conferencing. The public can participate via
videoconferencing. Register to join the video conference at:
https://us02web.zoom.us/webinar/register/" sHI3RcoCTOKPj4yzmTMQEg.
Public comment can also be provided via email to publiccomment2kalispell.com.
A. CALL TO ORDER
B. DISCUSSION ITEMS
Wastewater Treatment Plant Fermenter Phase 2 Condition Assessment
2. Stormwater Total Maximum Daily Load (TMDL) Action Plan
C. PUBLIC COMMENT
Persons wishing to address the council are asked to provide public comment via email to
publiccomment(cr�,kalispell. com or verbally during the online meeting. Register to join the
meeting at:
https://us02web.zoom.us/webinar/register/WN sHI3RcoCTOKPj4yzmTMQEg.
D. CITY MANAGER, COUNCIL, AND MAYOR REPORTS
E. ADJOURNMENT
UPCOMING SCHEDULE / FOR YOUR INFORMATION
Next Regular Meeting — April 5, 2021, at 7:00 p.m. — Council Chambers
Next Work Session — April 12, 2021, at 7:00 p.m. — Council Chambers
Watch City Council sessions live on Charter Cable Channel 190 or online at the Meetings on
Demand tab at www.kalispell.com.
Page 1 of 1
CITY OF k1l 111110146
KALISPELL
To: Doug Russell, City Manager
From: Susie Turner, P.E., Public Works Director
201 ]"Avenue East, P.O. Box 1997,
Kalispell, MT 59903-Phone (406) 758- 7720
www.kalispell.com
Re: Wastewater Treatment Plant Fermenter — Phase 2 Condition Assessment
Meeting Date: March 22, 2021
Enclosures: Technical Memorandum — Fermenter Conditions Assessment
The existing fermenter tank was constructed during the 2007-2009 Phase 1 WWTP
Improvements Project.
The primary purpose of a fermenter is to produce
supernatant (liquid by-product) which contains
volatile fatty acids (VFAs) utilized in the treatment
process to facilitate phosphorous removal. The
fermentation system is a critical component of the
treatment process and necessary to achieve low
effluent phosphorus concentrations.
In July 2020, a condition assessment was
performed to ascertain the condition of the structural and mechanical components of the
fermenter after over a decade of continuous operation.
The condition assessment evaluated the fermenter concrete, concrete coatings, piping,
hardware, equipment, launder, ventilation system, and access points. The initial assessment
yielded some insight into the condition of structure and equipment. Unfortunately, areas of
contaminated concrete were discovered as well as section loss of interior steel components.
These identified areas of concern, i.e., internal concrete and steel components, require
additional in-depth evaluation.
The recommended Phase 2 Assessment will include a deeper look in the concrete and steel
components, as outlined in the bullets below. The second assessment will provide a better
understanding of the condition of the deteriorated components of the fermenter and aid in the
development of the rehabilitation strategy.
• Concrete: Inspect, analyze, and evaluate the structural integrity of the contaminated
concrete in the fermenter including the walls, floor, and launder.
Steel: Inspect, analyze, and evaluate the status of existing metal structure and metal
protective coating in the fermenter. Perform thickness readings on metal components to
determine extent of section loss.
The objective of this work session is to inform City Council of the condition of the fermenter, the
Phase 2 Assessment strategies, and the estimated future rehabilitation timelines.
Technical Memorandum
Date: Friday, November 13, 2020
Project: Fermenter Condition Assessment
To: Susie Turner, City of Kalispell Public Works Director
Aaron Losing, City of Kalispell WWTP Manager
From: Gregory Mieczkowski NACE Level III #9254 Lizzy English Muir NACE Level 1 #78618
Subject: Fermenter Condition Assessment
1. Introduction
HDR Engineering, Inc. (HDR) performed a site visit to the Kalispell Advanced Wastewater
Treatment Plant (AWWTP) on July 27, 2020 to perform a condition assessment on the Primary
Sludge Fermenter. The fermenter was constructed during the 2007 Phase 1 project and the one
year warranty inspection revealed that the coatings on the concrete were delaminating. The
coatings were removed and completely re -applied after the one year warranty inspection.
The fermenter was emptied and cleaned by the City prior to the July 271" site visit to provide
HDR with a clean environment in which to inspect and observe the condition. The condition
assessment evaluated the fermenter in its entirety, including the concrete, concrete coatings,
piping, hardware, equipment, launder, ventilation system, and access points.
2. Record Review
Kalispell Advanced Wastewater Treatment Plant Phase 1
Expansion Contract Documents
HDR teamed with Morrison Maierle on the design and construction administration for the
Kalispell AWWTP Phase 1 Expansion project. The applicable contract documents (As -built
drawings and construction photos) were studied prior to the infield assessment to strategize the
assessment methodology and to understand the products and materials to expect.
3. Test Methods
The test methods described below were used during the condition assessment.
Visual and Photographic Inspection
Inspections and testing were performed on foot from inside the structure. Confined space entry
support was provided by City of Kalispell AWWTP staff, while the HDR Coatings Specialist
performed a dry footed inspection on top of the cover and inside the Fermenter basin. The
camera used for documentation was equipped with a flash and a neck strap for secure handling.
Documentation of the visual observations were also collected with a cellular phone camera.
1
HDR's Coatings Specialist performed the inspection in a systematic and organized manner to
provide a comprehensive evaluation of the structure. HDR staff started with the exterior of the
basin, then moved to the aluminum stairway and cover, and finally into the fermenter working
downwards in elevation.
Concrete Soundinq with Hammer
Sounding with a hammer is a non-destructive way to evaluate the condition of the concrete.
Good concrete makes a ringing sound when struck with a hammer and degraded cracking
concrete produces a hollow drum -like sound.
4. Findings
On the exterior of the Fermenter the aluminum components were in satisfactory condition. The
coating systems and the steel and concrete substrate were found to be in unsatisfactory
condition and the coatings performance did not meet the requirements described in the contract
documents. Observations verified that the coating systems were not applied or cured in
accordance with the specification and the material manufacturer's recommendations.
Additionally, the substrate preparation was insufficient leading to delamination of the protective
coatings.
Overall Condition
The visual inspection did discover significant defects, evidence of poor workmanship, and
product performance deficiencies. Areas of generalized rusting and pitting on the steel structural
support beams were discovered during inspection. Additionally, there was significant
deterioration on the concrete inside the basin including concrete spalling due to corroding steel
reinforcement. The condition of the individual fermenter components are discussed in the
following sections in more detail.
4.1.1 Aluminum Cover and Stairway
The aluminum cover on the fermenter (Figure 1) was found to be in good condition. The
aluminum stairway (Figure 2) and aluminum handrail was also found to be in good condition.
The treads on the stairs are aluminum with non -slip coatings on the top edges. The stair treads
are fastened down with stainless steel clips, however the lock nuts in random locations are
rusting, including the bolts which are anchored to the galvanized supports. The stairway
supports are anchored well to the sidewall of the unit with stainless steel bolts and nuts. An
aluminum stairway support angle at the top of the stairs was observed to be corroding (Figure
3).
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Figure 1. Aluminum Cover in Good Condition
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Figure 2. Aluminum Stairway in Good Condition
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Figure 3. Corroding Stairway Support
4.1.2 Anchor Points and Fasteners
The anchor points and fasteners on the aluminum cover were found to be in good condition.
4.1.3 Aluminum Cover Hatches
The nine aluminum cover square launder hatches were found to be in good condition. The two
aluminum cover flush hatches were found to be in good condition. The aluminum cover
supernatant hatch was also found to be in good condition.
4.1.4 Air Intake and Exhaust
The 12-inch gravity air intake on the northwest side of the fermenter and the exhaust duct on
the southeast side of the fermenter were found to be in good condition.
4.1.5 Drive Mechanism, Drive Assembly, and Associated Piping
The fermenter mechanism appeared to be in good condition aside from some delamination in
the blue coatings. This should be recoated during any potential fermenter rehabilitation project.
The insulation for the 3-EW piping has begun separating and exposing the piping, fittings, and
the flanges bolts. The condition of the 3-EW and 4-EW piping is unknown until the insulation is
replaced. New insulation should to be rewrapped and banded.
0
4.1.6 Exterior Tank Wall
Crazed cracking was observed on the coatings of the exterior concrete tank wall (Figure 4).
Adhesion testing was performed on the wall in accordance with ASTM 6677, and the results of
the test indicated the adhesion of the coatings were very weak.
Figure 4. Crazed Cracking on Exterior Concrete Wall
4.1.7 Scum Box Hatch
The diamond plate hatches over the FRP grating were observed to be in good condition.
4.1.8 Scum Wet Well
The scum wet well was found to be in good condition overall. The top landing double leaf
aluminum hatch was opened by City staff to observe the interior of the wet well (Figure 5). The
scum wet well appears to be coated from the bottom of the inlet piping all the way down to the
bottom of the wet well. The transducer is non-functional and the City does not wish to replace it.
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Figure 5. Scum Wet Well in Good Condition
The pipe inside the scum wet well is the overflow pipe according to information provided by the
City. The 6-inch or 8-inch pipe on the south elevation of the scum pit is the pipe associated with
the scum beach. The coating appears to be a Polybrid 705 and it is beginning to delaminate at
the wall/hatch interface on the south elevation.
Some crazed cracking was evident on the exterior scum walls.
4.1.9 Bridge Beam and Tank Wall Recess, Fasteners
General rusting was observed on these bridge beams, especially in the areas where the beams
are recessed and mounted into the tank wall. However, the extent of corrosion will not be
definitively determined until the components are abrasively blasted. The aluminum cover will
likely need to be removed to perform proper and thorough blasting. Photos of the rusting can be
seen in Figure 6 and Figure 7.
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Figure 6. Bridge Beam With General Rusting
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Figure 7. Bridge Beam Rusting At Edges
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7
4.1.10 Launder
The coating in the launder has large blisters that have cracked and the coating has started to
peel in various locations. Two pieces of the existing coating in the launder have been archived
for further examination of dry film thickness. There are several locations on the 5`6" launder wall
that are showing H2S corrosion on the concrete, thereby exposing aggregate. A photo of the
exposed aggregate beneath delaminating coatings can be seen in Figure 8.
- , r
Figure 8. Launder Exposed Aggregate
Notable delamination was found in the vicinity of the fermenter launder trough and when the
coatings were manually removed a pink/purple staining was uncovered. Further testing will be
needed to identify what has caused the staining shown in Figure 9
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a ,97120i.2 2 `{1��L�1L/ �y y,� q�n�j
Figure 9. Purple Staining and Discoloration Under Delaminating Coating
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There are also locations on the launder weir side that are experiencing concrete degradation
and vertical cracking is further exposing the aggregate. A pH test was performed on the
concrete at the inside of the crack and where the first layer of degraded concrete was chiseled
away. Photos of the launder vertical cracking can be seen in Figure 10.
Figure 10. Launder and Coating Cracking
Concrete sounding by hammer was performed at the 12 o'clock position on the vertical crack in
Figure 10 and no hollow sound was witnessed. The vertical crack at the launder wall was
chiseled away to depth of approximately 3/4 of an inch where the red pH rainbow indicator
showed a pH level between 11 and 13. A photo of the pH examination and depth of the
chiseling can be seen in Figure 11.
Figure 11. Chiseled Crack pH Coloring
In another location, 3/4 of an inch just above the crack was also chiseled. The pH indicator in
the chiseled area came up at pH of 13 at a depth of a 1/4 of an inch. Vertical cracks throughout
the inner -diameter inside launder wall were contaminated to 3/4 of an inch thickness from H2S
gas.
On the basin side of the launder inner -diameter wall the coating was applied to 12 inches below
the launder down the basin wall. No keyway was present for proper termination of the coatings.
Without proper termination, the edge of the coatings have pulled away and is allowing moisture
to creep up behind the coating. Cracks were visible on the basin side of the launder and were
the same condition as on the inside. The true condition of these areas will be unknown until the
coatings are removed and further concrete testing is performed.
4.1.11 Launder Trough
The examination of the launder trough found that there is a keyway but the coating is
nonetheless peeling away from the substrate. A pink/purple staining was also observed in the
area and shown in Figure 9. A photo of the launder trough and the significant delamination of
the coatings can be seen in Figure 12.
10
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Figure 12. Delaminating Coating on Launder Trough
4.1.12 Skimmer and Counterweight
The City performed a temporary skimmer repair during the fermenter inspection. Additional
repairs shall be performed during the rehab outage. The counterweights are rusted but still well
fastened, they shall be taken apart and individually coated and reinstalled during the
rehabilitation period.
4.1.13 Supported Piping: 6-SC, 6-PS, 4-EW and Supports
The six-inch SC pipe is stainless steel and dielectrically isolated from beach scum. It has
stainless steel hardware fastened to the interior wall.
The 6-PS and 4-EW piping are also stainless steel and properly isolated from the pipe supports
and the influent well beams and influent well. Figure 13 shows the 6-PS, 4-EW, supports,
influent beam and influent well.
4.1.14 Influent Well I -Beam and Pipe Support
General rusting was observed on the influent well beams at 6 o'clock and 12 o'clock. These
locations correspond to the southernmost and northernmost ends, respectively, of the beams as
they abut the concrete wall where they are mounted. Figure 13 shows how the influent beams
support the influent well as well as the 6-PS penetration into the influent well.
11
Figure 13. 6-PS, 4-EW, Influent Beam, Influent Well
4.1.15 Center Torque Tube
The main square tubing of the center torque tube is in good condition with the exception of the
bolts at the flanged ends that connect the upper and lower segments of the tubing. The nuts
and bolts have experienced significant corrosion with the lack of proper isolation of dissimilar
metals and must be replaced.
Figure 14. Torque Tube Flanges with Corroded Nuts and Bolts
12
4.1.16 Scum Trough
The scum trough was found to be in good condition.
4.1.17 4-foot Wide Scum Beach
The scum beach support was found to be in good condition. The scum beach is carbon steel
and is well fastened to the wall.
4.1.18 Scum Blade
The scum blade had a torn corner (Figure 15) that will require replacement.
Figure 15. Torn Scum Blade and End of Skimmer Counterweight Arm
4.1.19 Scum Weir and Baffle
The scum weir and baffle components are FRP and include brackets with stainless steel
hardware. These will be removed, "saved", and then re -installed after concrete rehabilitation is
complete.
4.1.20 Concrete Walls
Exposed aggregate (Figure 15 and Figure 16) and concrete spalling (Figure 17) due to corroded
rebar was observed on the interior of the fermenter.
13
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Figure 16. Exposed Aggregate on Interior Concrete Fermenter Floor
Figure 17. Exposed Aggregate on Interior Concrete Fermenter Floor
14
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Figure 18. Vertical Spalling from Corroding Rebar
At 11 o'clock on the basin side wall an area rusting from corroding rebar through the concrete
was observed. Exposed aggregate also was observed in this area approximately 10 feet off the
floor. Furthermore, no cracking was observed on the concrete floor but the exposed aggregate
was evident as well as the spacing between the floor and the plow blade with squeegees. The
squeegees are designed to scrape along the floor with contact at all times. In many locations
the squeegees have no contact with the floor.
4.1.21 Plow Blade and Trusses
The plow rake arm is carbon steel and was observed to be in good condition. The trusses of the
plow blade were also in good condition.
15
4.1.22 Tide Flex Valves
The tide flex valves were observed to be in sufficient condition but should be replaced at the
time of the fermenter rehabilitation.
4.1.23 Hopper Scraper and Truss
The hopper scraper and truss were submerged in water and were not accessible for visual
assessment.
4.1.24 Supernatant Wetwell
The supernatant wetwell (Figure 16) was found to be in poor condition with significant corrosion.
w
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Figure 19. Supernatant Wetwell in Poor Condition
5. Recommendations
This initial assessment of the fermenter yielded some insight into the condition of system, but
also lead to more questions. There are a number of testing procedures that can be performed
to better understand the extent of the contaminated concrete as well as the loss of structural
integrity in the structural steel. While many of the smaller nuts and bolts are easily identified
and replaced, the concrete and larger steel components may have underlying issues that need
to be explored. The following is a list of recommended tests and methods that HDR would like
to discuss with the City to develop the plan for the follow-up condition assessment.
• Surface penetrating radar unit will indicate if the rebar has good depth of cover.
• Extract cores from the concrete, at a depth to be determined, to see how the following
constituents vary with depth:
16
o pH - as pH decreases the rate of concrete deterioration increases and concrete
becomes more porous,
o Carbonation - CO2 in the presence of moisture can form carbonic acid which
attacks the concrete and reduces the alkalinity,
o Chlorides - chlorides can weaken and permeate through concrete and therefore
increases the risk of reinforcement corrosion,
o Compressive strength - will indicate how much strength has been lost and to
what depth in the core,
o Iron Content - the iron concentration in the fermenter liquid is very high which
promotes bacterial growth which leads to corrosive environment.
• Energy Dispersive Spectroscopy - EDS which is a qualitative elemental analysis that
will indicate what inorganic substances are present.
• Thickness readings on the structural steel beams flanges and webs to determine
extent of section loss.
HDR has the capabilities to perform the tests listed or to collect the necessary samples to send
to an appropriate lab. However, a separate contractor will need to be retained to take the
concrete cores to then be sent to a lab for analysis.
We appreciate the opportunity to work with you and look forward to a discussion to determine
next steps.
Regards,
Lizzy English Muir, PE Greg Mieczkowski
HDR NACE 1 Coatings HDR NACE III Coatings Inspector
Inspector and Project
Engineer
17
CITY OF
KALISPELL
MEMORANDUM
To: Doug Russell, City Manager
From: Susie Turner, P.E., Public Works Director
Re: Stormwater TMDL Action Plan
Meeting Date: March 22, 2021
Enclosures: Report — Stormwater TMDL Action Plan (Final Draft)
BACKGROUND: The City of Kalispell is permitted by the Montana Department of
Environmental Quality (DEQ) under the General Permit for Stormwater Discharges Associated
with Small Municipal Separate Storm Sewer Systems (Small MS4s). The purpose of the permit
is to protect local water quality by reducing and preventing urban stormwater pollutants from
entering the storm system and local water bodies.
The 5-year permit (2017-2021) requires the City to develop and maintain a stormwater program.
Within the permit, there are yearly programmatic requirements. In permit year four (2020), the
City was required to develop a section of the Stormwater Management Plan that addresses
applicable total maximum daily loads (TMDLs). The permit required that the TMDL section
include:
• Identification of measures and best management practices (BMPs) the permittee plans to
implement
• Description of the MS4's impairment priorities and long-term strategy
• An outline of interim milestones for controlling the discharge of the pollutants of
concern and making progress towards meeting the TMDL.
The purpose of the Stormwater TMDL Action Plan is to maintain compliance with the MS4
permit. The plan contains background information, details on TMDLs with MS4 approved
wasteload allocations, and a plan for addressing TMDLs.
The objective of this work session is to present an overview of the MS4 permit regulations and
the contents of the Stormwater TMDL Action Plan, as well as provide a review of the various
methods and practices the City utilizes to reduce and prevent stormwater pollution to meet the
TMDL.
201 1"Avenue E Phone (406)758-7720
Po Box 1997 Public Works Department Fax (406)758-7831
Kalispell, MT 59903 1 1 www.kalispell.com
Sto rmwate r T M D L
Action Plan
City of Kalispell, Montana
Stormwater Management Program
Kalispell, MT
February 18, 2021
This page intentionally left blank
City of Kalispell I Storm Water Management Program
Stormwater TMDL Action Plan
Table of Contents
1 Introduction...........................................................................................3
1.1 Mission...............................................................................................................
3
1.2 Background........................................................................................................
3
1.2.1 Permitting.............................................................................................................
3
1.2.2 Growth Policy........................................................................................................
3
1.3 Purpose..............................................................................................................4
2 MS4 Permit TMDL Requirements..........................................................4
2.1 Addressing TMDLs in the SWMP.......................................................................4
2.2 TMDL-Related Monitoring..................................................................................4
3 TMDLs with MS4 Approved WLAs........................................................4
3.1 Pollutants of Concern and WLAs.......................................................................
6
3.1.1 Nutrients (Total Phosphorus, Total Nitrogen, Nitrate + Nitrite) ...............................
7
3.1.2 Dissolved Oxygen.................................................................................................
7
3.1.3 Sediment..............................................................................................................
7
3.1.4 Temperature.........................................................................................................
7
4 Stormwater Action Plan for Addressing TMDLs.....................................8
4.1 Impairment Priorities and Long-term Strategy ....................................................
8
4.1.1 Impairment Priorities: Sub -basin Prioritization.......................................................
8
4.1.2 Long-term Strategy..............................................................................................11
1. Pollution Prevention & Good Housekeeping (i.e. Municipal Operations)..................11
2. Education & Outreach.............................................................................................12
3. Construction Site Stormwater Management............................................................12
4. Water Quality Treatment Applications & Capital Improvement Plan.........................13
5. Low Impact Development........................................................................................15
6. Stormwater TMDL & Self-Monitoring.......................................................................16
4.1.3 Funding................................................................................................................16
4.1.4 Adaptive Management.........................................................................................17
4.2 Schedule and Progress Towards Meeting the TMDL.......................................
17
4.2.1 Schedule for Action Items....................................................................................17
4.2.2 Measuring Progress towards Meeting the TMDL.................................................18
Non -Structural BMPs......................................................................................................20
StructuralBMPs.............................................................................................................20
4.2.3 Estimation of Recent Historical Progress towards Meeting the TMDL..................24
5 References.......................................................................................... 27
Appendix A: TMDL Progress Reporting
Appendix B: Treatment Scenarios
Appendix C: TMDL Sampling Plan
Figures
Figure 1.
Highest Priority Sub -Basins in City of Kalispell...........................................................10
Figure 2.
City of Kalispell Stormwater TMDL CIP Strategy........................................................15
Figure 3.
Anticipated Schedule of Structural and Non -Structural Action Items ..........................18
Figure 4.
2020 Ashley Creek Estimate of Total Pollutant Reductions........................................25
Figure 5.
2020 Spring Creek Estimate of Total Pollutant Reductions........................................25
Figure 6.
2020 Stillwater River Estimate of Total Pollutant Reductions.....................................26
Tables
Table 1.
Impaired Waterbodies within Kalispell City Limits.........................................................
5
Table 2.
TMDL Loads and MS4 Wasteload Allocations..............................................................
6
Table 3.
Stormwater Outfalls Discharging to Impaired Surface Waters ......................................
8
Table 4.
DEQ TMDL Reference Pollutants of Concern Percent Removals................................19
Table 5.
Summary of Pollutants of Concern Removed by Non -Structural BMPs.......................20
Table 6.
2020 Pollutant Reductions from Non -Structural BMPs by Waterbody ..........................20
Table 7.
Example Reduction Progress Evaluation for a Single BMP.........................................21
Table 8.
Example Reduction Progress Evaluation for Multiple Scenarios..................................22
Table 9.
Reduction Progress Evaluation for Impaired Waterbodies from Structural BMPs ........23
Table 10.
Reduction Progress Evaluation for Ashley Creek from Structural BMPs....................23
Table 11.
Reduction Progress Evaluation for Spring Creek from Structural BMPs ....................23
Table 12.
Reduction Progress Evaluation for Stillwater River from Structural BMPs .................23
Table 13.
Estimate of Total Pollutant Reductions within the MS4 in 2020.................................24
City of Kalispell I Storm Water Management Program
Stormwater TMDL Action Plan
1 Introduction
1.1 Mission
The City of Kalispell (City) seeks to provide long-term stormwater management by administering
a drainage and treatment system that protects properties and water quality through the strategic
use of limited finances while meeting regulatory requirements.
1.2 Background
1.2.1 Permitting
The City operates its storm drainage system under the authorization of the General Permit for
Storm Water Discharges Associated with Small Municipal Separate Storm Sewer Systems
(MS4s) (MTR040000). This MS4 General Permit (MS4 Permit) was approved by the Montana
Department of Environmental Quality (DEQ) in July of 2006, with subsequent re -approvals in
2010 and January 2017 (DEQ 2016) and is effective from January 1, 2017 through December
31, 2021. The MS4 Permit provides authorization to discharge stormwater to waters of the state
under the Montana Pollutant Discharge Elimination System (MPDES). Under this permit, the
City is required to develop, document, and maintain a Storm Water Management Plan (SWMP),
which includes management practices, control techniques, systems, designs, good standard
engineering practices, and other provisions necessary to reduce the discharge of pollutants
from the permitted MS4.
1.2.2 Growth Policy
The City's Growth Policy "lays out a framework to guide growth in and around the City for the
next 20 years", including consideration of limited financial resources and the growing population
(Kalispell 2017). Stormwater management goals are included in the policy, which demonstrates
the importance of the Stormwater Total Maximum Daily Load (TMDL) Action Plan. The policy
includes direct references to the MS4 Permit, satisfying those permit requirements, protecting
the environment and water quality, and addressing impaired waters (TMDLs). The stormwater
management goals from the Growth Policy are identified below:
GOALS:
1. Ensure adequate stormwater management facilities for all incorporated urban areas.
2. Improve the drainage and stormwater infrastructure in problem areas of the community.
3. Require all new development and redevelopment to have adequate stormwater
management facilities for storm event attenuation and water quality treatment.
4. Ensure maintenance and management of existing and new stormwater management
facilities are being performed on both public and private properties to maximize their use.
5. Meet all requirements of the permit including effluent limits, stormwater management
program, and special conditions for impaired waters and monitoring, recording, and
reporting requirements.
3
1.3 Purpose
The purpose of this document, the Stormwater TMDL Action Plan, is to address the
requirements in Part III Special Conditions Section B of the MS4 Permit. Part III Special
Conditions Section B requires the City to include in the SWMP a section addressing water
quality controls for storm discharges to impaired waterbodies that do not meet one or more
water quality standards and have an approved TMDL.
2 MS4 Permit TMDL Requirements
2.1 Addressing TMDLs in the SWMP
Per Part III Special Conditions Section B of the MS4 Permit, the permittee's SWMP must:
1. Identify:
a. All outfalls that discharge to impaired waterbodies with an approved MS4
Wasteload Allocation (WLA)
b. The impaired waterbodies
c. The associated pollutant(s) of impairment
2. Include a section:
a. Identifying the measures and best management practices (BMPs) it plans to
implement
b. Describing the MS4's impairment priorities and long-term strategy
c. Outlining interim milestones (i.e., a completion schedule for action items) for
controlling the discharge of the pollutants of concern and making progress
towards meeting the TMDL
3. Incorporate TMDL-Related Monitoring into the TMDL section.
Item 1 is required to be submitted with each Annual Report. Item 2 must be submitted with the
4t" year Annual Report for approval. The permittee will begin to implement the approved section
no later than the start of the 5t" permit year.
The TMDL section must be annually evaluated based on monitoring results, revisited as
needed, and resubmitted with Annual Reports beginning with the 5t" year Annual Report. Any
revisions to the section require rationale and must be approved by DEQ.
2.2 TMDL-Related Monitoring
The permittee must supplement the Self -Monitoring Requirements in Part IV of the MS4 Permit
with additional monitoring targeted at further evaluating MS4 loading to impaired waterbodies or
at evaluating the effectiveness of BMPs selected for reducing MS4 loading to impaired
waterbodies. See Appendix C for more information.
3 TMDLs with MS4 Approved WLAs
The City of Kalispell is within the Flathead — Stillwater Planning Area. Completed by DEQ in
2014, the Flathead — Stillwater Planning Area Nutrient, Sediment, and Temperature TMDLs and
0
Water Quality Improvement Plan identifies water quality targets, pollutant sources, and total
allowable pollutant loads (2014).
In Kalispell, the following waterbodies flow through City limits or receive stormwater discharges
from the City's MS4:
• Ashley Creek
• Bowser/Little Spring Creek (Unnamed tributary to Spring Creek — aka Kids Creek)
• Dry Bridge Slough
• Spring Creek
• Stillwater River
• Stillwater Slough / Muskrat Slough
• Whitefish River
• An unnamed perennial surface water tributary to Ashley Creek from Foys Lake
Of the above, the TMDL identifies four waterbodies as impaired: Ashley Creek, Spring Creek,
Stillwater River, and Whitefish River. Table 1 provides a list of impaired waterbodies and their
corresponding pollutants of concern within Kalispell City limits.
Although the TMDL lists WLAs for the pollutants of concern in these waterbodies, the WLAs are
not intended to add concentration or load limits to the MS4 Permit.
Table 1. Impaired Waterbodies within Kalispell City Limits
Waterbody & Location
Waterbody ID
Impairment Cause(1)
Pollutant Category(2)
Description
(Middle) Ashley Creek,
Smith Lake to Kalispell
Airport Road
MT760002_020
Nitrogen Total
Nutrients
Phosphorus Total
Nutrients
Sedimentation/Siltation
Sediment
Temperature, water
Temperature
Alteration in stream side or littoral
vegetative covers
Not Applicable; Non -pollutant
Chlorophyll a
Not Applicable; Non -pollutant
Nitrate/Nitrite Nitrite+Nitrate as N
Nutrients
(Lower) Ashley Creek,
Nitrogen Total
Nutrients
Kalispell Airport Road to
MT760002_030
Oxygen, Dissolved
Dissolved Oxygen
mouth (Flathead River)
Phosphorus Total
Nutrients
Sedimentation/Siltation
Sediment
Temperature, water
Temperature
Spring Creek,
Headwaters to mouth
(Ashley Creek)
MT760002 040
—
Nitrate/Nitrite Nitrite+Nitrate as N
Nutrients
Nitrogen Total
Nutrients
Oxygen, Dissolved
Dissolved Oxygen
Phosphor s Total
Nutrients
Stillwater River, Logan
Creek to mouth
MT76PO01_010
Alteration in streamside or littoral
ve etative covers
Not Applicable; Non -pollutant
Sedimentation/Siltation
Sediment
Whitefish River,
Whitefish Lake to mouth
MT76P00_010
Temperature, water
Temperature
Stillwater River
(1)Oxygen, Dissolved impacts are associated with nutrients and sediment and not further addressed in this plan.
(2)Nutrients are total nitrogen and total phosphorus
DEQ 2014 Table DS-1
5
3.1 Pollutants of Concern and WI -As
Six pollutants of concern are identified as part of the TMDL and MS4 Permit for the City:
• Total Phosphorus
• Total Nitrogen
• Nitrate + Nitrite
• Dissolved Oxygen
• Sediment
• Temperature
Total nitrogen, total phosphorus, and sediment WI -As for the Kalispell MS4 and their percent
reductions are identified in Table 2.
Table 2. TMDL Loads and MS4 Wasteload Allocations
Segment Load Ibs Percent Reduction 1 WLA 1
Total Nit oclen 2
Middle Ashley Creek 3
417
30%
292
Lower Ashley Creek 4
1,472
30%
1,030
Spring Creek
384
30%
269
Stillwater River
n/a
n/a
n/a
Whitefish River
n/a
n/a
n/a
Total Phosphorus 2
Middle Ashley Creek 3
26
44%
15
Lower Ashley Creek 4
97
44%
54
Spring Creek
24
44%
13
Stillwater River
n/a
n/a
n/a
Whitefish River
n/a
n/a
n/a
Sediment 5,6
Middle Ashley Creek
80,800
62%
30,800
Lower Ashley Creek
244,800
62%
93,000
Spring Creek
n/a
n/a
n/a
Stillwater River
86,800
62%
33,000
Whitefish River
n/a
n/a
n/a
Temperature
Middle Ashley Creek
Follow the minimum control measures provided in the MPDES permit authorization
for permit MTR04005, or any subsequent permit renewals.
Lower Ashley Creek
Spring Creek
n/a
Stillwater River
n/a
Whitefish River
Follow the minimum control measures provided in the MPDES permit authorization
for permit MTR04005, or any subsequent permit renewals.
(1) These values are not intended to add concentration or load limits to the MS4 Permit; meeting permit BMP and
other requirements equates to meeting the total nitrogen and total phosphorus WI -As. WLA = Wasteload
Allocation
(2) Load and WLA for nutrients are given as growing season, July 1 through September 30.
(3) Middle Ashley Creek includes the load for Spring Creek.
(4) Lower Ashley Creek includes the loads from Middle Ashley Creek and Spring Creek.
(5) Load and WLA for sediment are given as annual limits.
(6) The MS4 permit does not include effluent limits, but requires the development and implementation of a
stormwater management program (SWMP) to minimize sediment loading to surface waters.
Source: DEQ 2014 Table 5-22, Table 5-23, Table 6-21, and Table 7-2
A
3.1.1 Nutrients (Total Phosphorus, Total Nitrogen, Nitrate + Nitrite)
Applicable waterbodies: Ashley Creek (middle and lower), Spring Creek
Per the TMDL, the MS4 does not continuously discharge nutrients and therefore the WLA is
only applicable during the dry summer growing season (July 1 — September 30). Percent
reduction allocations were developed, but the WI -As are not intended to add load limits to the
permit. The WI -As are met by adhering to the MS4 Permit requirements (DEQ 2014; DEQ
2016).
According to the MS4 Permit, the total nitrogen TMDL for Lower Ashley Creek provides a
surrogate TMDL and allocations to address the Nitrate + Nitrate impairment and water quality
improvements that address excess nitrogen loading will result in a decrease in Nitrate + Nitrite.
For these reasons, Nitrate + Nitrite are not addressed further in this Action Plan.
3.1.2 Dissolved Oxygen
Applicable waterbodies: Ashley Creek (lower), Spring Creek
There are no dissolved oxygen WI -As for the MS4.
The MS4 Permit states that water quality improvements that address nutrients (nitrogen and
phosphorus) will result in improved DO concentrations. By adhering to MS4 permit
requirements, DO will improve. For this reason, DO is not addressed further in this Action Plan.
3.1.3 Sediment
Applicable waterbodies: Ashley Creek (middle and lower), Stillwater River
Percent reduction allocations were developed, but the WI -As are not intended to add load limits
to the permit. The WI -As are met by adhering to the MS4 Permit requirements (DEQ 2014; DEQ
2016).
3.1.4 Temperature
Applicable waterbodies: Ashley Creek (middle and lower), Whitefish River
There are no temperature WI -As for the MS4.
According to the MS4 Permit, "discharge temperatures will be consistent with naturally occurring
conditions by the City of Kalispell MS4 adhering to the MS4 Permit requirements" (DEQ 2014;
DEQ 2016).
However, installed BMPs can be beneficial for temperature impaired waterbodies. For example,
infiltration basins, bioretention, and dispersion are preferred BMPs when considering
temperature impairments, while extended detention basins and wet detention basins should be
avoided (HDR 2017). Temperature is addressed through consideration of BMP selection for
new and redevelopment projects within the City as well as for public capital improvement
projects. Therefore, it is not further discussed in this Action Plan.
7
4 Stormwater Action Plan for Addressing TMDLs
The City conducts extensive planning to maintain and operate the MS4. Focusing on removing
and reducing pollutants in stormwater through both structural' and non-structural BMPs2
provides a well-rounded approach to the complex and variable nature of stormwater. Even
though the TMDL emphasizes that the MS4 will meet WLAs by adhering to the MS4 Permit
requirements, the City strategically incorporates capital projects centered on impaired
waterbodies to reduce stormwater pollutants. Combining the structural water quality
improvement projects with non-structural BMPs (i.e. street sweeping, public outreach, etc.),
provides greater benefits to water quality in the long-term.
0 Impairment Priorities and Long-term Strategy
4.1.1 Impairment Priorities: Sub -basin Prioritization
Within City limits, there are 78 stormwater outfalls that discharge into surface waters. Outfall
ownership varies; some are owned and maintained by the City, others by Montana Department
of Transportation, and some are privately owned and maintained. A complete list of the City's
outfalls is presented in Appendix A of the SWMP (Kalispell 2021).
Of the stormwater outfalls, 67 discharge to the four impaired waterbodies. Table 3 identifies
impaired waterbody outfalls and the number of outfalls per waterbody.
Table 3. Stormwater Outfalls Discharging to Impaired Surface Waters
Waterbody Stormwater
City Assigned Outfall Code
Number of Outfalls
Waterbody
Sub -basin Drainage Area
(2)
that Discharge to
Acres 1
Impaired Waterbodies
Ashley Creek
1,214.16
AC1 —AC 11, AC13—AC21,
23
middle and lower
UT1—UT3
Spring Creek
1,130.08
SC1—SC2, SC4, SC6—SC25
23
Stillwater River
1,237.91
SWR1—SWR11, SWR14-
19
SWR17, SWR19-SWR22
Whitefish River
14.22
WFR1—WFR2
2
(1) Sum of drainage areas as shown in Appendix A of Kalispell 2021. Excludes closed basins.
2 Outfall codes as shown in Appendix A of Kalispell 2021.
In order to progressively reduce stormwater pollutants entering impaired waterbodies, urban
sub -basins (subwatersheds), areas that drain to a designated outfall, need to be ranked and
prioritized based on which have the largest pollution potential to negatively impact water quality.
Once sub -basins with the largest pollution potential are identified, those basins can be targeted
for both structural and non-structural BMPs (private and public) to improve stormwater quality
leaving the sub -basin.
As part of the Illicit Discharge Detection and Elimination (IDDE) program operated by the City
(and required by the MS4 Permit), the City uses a desktop assessment to determine which sub-
' Structural BMPs refer to constructed structures designed to provide water quality treatment. See HDR 2017.
2 Non-structural BMPs refer to actions (i.e. City street sweeping, public programs, etc.) designed to provide water quality benefits.
basins have the greatest pollution potential within the City's MS4. As described in Appendix C of
the SWMP, this prioritization for the IDDE program was developed with the following steps:
1. Delineate sub -basins or drainage areas within the City
2. Compile available mapping and data for each drainage unit (e.g. land use, age, outfalls,
infrastructure history)
3. Calculate sub -basin discharge screening factors using GIS analysis
a. Screening factors include:
i. Past illicit discharge complaints and reports
ii. Areas prone to incidents of illegal dumping
iii. Age of storm sewer in sub -basin
iv. Areas primarily served by onsite sewage disposal systems
v. Amount of industrial area draining to outfall
vi. Outfall discharges to an impaired water body
vii. Size of drainage basin
4. Screen and rank pollution potential at the sub -basin and community level
5. Generate maps to support field investigations
Resulting from this assessment is a prioritization list of sub -basins based on the risk for pollution
and illicit discharges (See MS4 Annual Report). Based on the 2020 IDDE priority ranking, the
following sub -basins were identified as the highest priority based on their normalized Illicit
Discharge Potential score (Figure 1):
1. AC6
1. SC1
1. AC11
2. SWR4
3. AC2
3. AC21
3. SC6
3. SC16
3. SWR7
Determination of the location of new structural BMPs and measures to address TMDLs utilizes
the prioritization list. Selection of the type of new structural BMPs and measures to address
TMDLs includes information about the land use, target pollutants, performance capabilities,
physical site capabilities, aesthetics, safety, maintenance requirements, and cost (HDR 2017).
As each BMP implementation has unique goals and constraints, no single BMP will be selected
in all scenarios, but rather prioritized and selected as described above.
9
a
i
Drainage Basin
�J AC6
0 SC1
® AC11j
0 SWR4
0 AC2
AC21
0 SC6
0 SC16
�� SWP
N
0 005 1 2 Miles ESri, HERE
I
Figure 1. Highest Priority Sub -Basins in City of Kalispell
10
4.1.2 Long-term Strategy
The long-term strategy of the City to address impaired waterbodies and their associated TMDLs
includes prioritizing pollutant reduction BMPs within sub -basins with the greatest potential to
protect water quality, employing structural and non-structural approaches, and utilizing public
water quality projects while maintaining private water quality development requirements. Using
an adaptive approach, BMP performance will be evaluated through stormwater sample
collection and analysis. The results will be used to make informed decisions on best practices
locally. By continuing to make incremental progress, the City continues to prevent and remove
stormwater pollutants from entering local waterbodies and ultimately meet TMDL goals.
Since stormwater pollution is variable, it is important to have a varied approach to pollutant
reduction. Pollutants in stormwater are targeted primarily by using BMPs identified in the TMDL
(DEQ 2014) and its cited references, the MS4 Permit (DEQ 2016), and the SWMP (Kalispell
2021). The City will employ or continue to employ structural and non-structural BMPs within the
following categories:
1. Pollution Prevention & Good Housekeeping (i.e. Municipal Operations)
2. Education & Outreach
3. Construction Site Stormwater Management
4. Water Quality Treatment Applications & Capital Improvement Projects
5. Low Impact Development
6. Stormwater TMDL & Self -Monitoring
1. Pollution Prevention & Good Housekeepinq (i.e. Municipal Operations)
Long -Term Strategy
Utilize operation -based programs and initiatives, such as street sweeping and infrastructure
cleaning, targeting pollutants of concern for the MS4's impaired waterbodies. These
activities provide pollutant reduction through economical and sustainable administrative and
operational activities.
BMPs
- Treatment Unit & Infrastructure Maintenance
Water quality treatment units, catch basins, storm drain inlets, and other conveyance
structures are cleaned regularly to remove sediment and debris. Each year, the cubic
yards of sediment and debris removed from infrastructure is collected and used to
calculate an estimate of yearly tons of sand/sediment removed from the MS4 and
prevented from reaching local waterbodies.
Street Sweeping
Kalispell streets are swept on a routine basis. During spring sweeping operations,
streets are swept more often to collect winter sanding material. Routine sweeping
practices include:
■ Operating sweepers to get optimal debris removal
■ Additional sweeping if a storm drain is plugged or high pollutant loading has been
found in certain area
■ Sweeping immediately after street, water, and sewer repair projects
11
■ Sweeping after special events such as street fairs, art shows, and parades
Each year, the cubic yards of sweepings are collected and used to calculate an estimate
of yearly tons of sand/sediment removed from the MS4 and prevented from reaching
waterbodies.
Leaf Collection
Kalispell streets are swept and cleaned on a routine basis in the fall to collect leaves.
During fall leaf collection operations, leaves are removed from streets, curbs, and gutters
using sweepers, loaders, and vacuum trucks. Public service announcements are
advertised through social media outlets to inform Kalispell citizens of the correct leaf
collection and disposal method and routes. The leaves are collected and deposited at
the City compost yard.
Each year, the cubic yards of leaves are collected and used to calculate an estimate of
yearly tons of leaves removed from the MS4 and prevented from reaching waterbodies.
2. Education & Outreach
Long -Term Strategy
Implement education -based programs and initiatives, such as targeted community
outreach, focused on pollutants of concern for the MS4's impaired waterbodies. Targeted
outreach reduces pollutants of concern by focusing on those within the MS4 who are most
likely to influence pollutant loading.
BMPs
- Community Activities & Education
Various non-structural measures are employed to reduce pollutants entering local
waterbodies. Programs designed for residents (i.e. Flathead Rain Garden Initiative)
provide education and on -site assistance with stormwater pollution and best
management techniques. The City also provides information on best practice awareness
to businesses that commonly contribute to stormwater pollution via handouts, field visits,
and emails.
3. Construction Site Stormwater Management
Long -Term Strategy
To prevent additional pollutants from reaching waterbodies, continue to maintain the City's
construction site stormwater management program. The Construction Stormwater Permit
program provides oversight and enforcement mechanisms on all construction sites greater
than 1,000 square feet or five cubic yards of disturbance.
BMPs
- Permit Review
Construction Stormwater Permit submissions are reviewed for completeness and
adequacy. Review provides an opportunity for guidance and education and can reduce
compliance issues.
Site Inspections
12
Construction sites are inspected to ensure compliance and reduce impacts to water
quality. Inspections also provide opportunities to inform contractors on appropriate
stormwater management controls and why they are needed to protect local waterbodies.
Training Programs
The City helps support local construction stormwater training programs and classes.
Training provides contractors with the knowledge and background necessary to
effectively control pollutants on construction sites.
Water Quality Treatment Applications & Capital Improvement Plan
Long -Term Strategy
On both public and private projects, utilize industry standard treatment technologies, such
as mechanical separation (80% TSS removal under certain conditions), to mitigate urban
pollutant impacts. Treatment technology provides effective, maintainable, and economical
treatment systems near stormwater discharge points for the MS4's large, urban drainage
areas currently lacking treatment before discharge.
Public Projects: Continue to utilize the Capital Improvement Plan (CIP) to plan and construct
projects that address water quality as well as those that focus on infrastructure, flooding,
and/or other issues not directly related to water quality.
Incorporating stormwater projects into capital planning allows these projects to be
adequately budgeted for and included in scheduling. Occurring annually, the planning
process allows for public comment, requires approval by the City Council, and is
incorporated into the fiscal year's operating budget. Often spanning several years from the
CIP approval, the process includes preliminary engineering, developing an engineered
design, bidding out the project, and construction. The five-year CIP is outlined in the SWMP
(Section 4 Program Performance -Table 1) (Kalispell 2021).
Private Projects: Maintain requirements for privately -owned new and redevelopment projects
to provide water quality treatment. Continue post -construction program oversite for
sustainable operation and maintenance of the private treatment applications.
BMPs
- Stormwater TMDL CIPs
Utilize the steps below for strategizing stormwater TMDL-related CIPs (Figure 2):
1. Assessment: Using the sub -basin prioritization method, determine priority sub -
basins for treatment (generally large, mostly untreated stormwater sub -basins
discharging into impaired waterbodies).
2. Plan and Construct CIP: Identify funding for projects to provide water quality
treatment to the prioritized sub-basin(s) and schedule in the CIP.
3. Monitor: Monitor stormwater via the sampling plan to gain information on BMP
performance in demonstration/representative sub -basins.
4. Adaptive Management: Evaluate, revise as needed, and repeat.
CIPs must consider budget constraints to ensure expenditures are equal to funds
available from the utility assessment. Additionally, it is important to consider other
13
planned projects. Combining stormwater projects with other City initiatives, such as road
reconstructions, reduces costs.
City -Owned Structural Treatment
Structural BMPs owned by the City are inspected and maintained on regular schedules
(see Pollution Prevention & Good Housekeeping section). Inspections, maintenance,
and debris removed from water quality treatment structures are tracked with an asset
management program.
Privately -Owned Structural Treatment
City of Kalispell's Standards for Design and Construction: Privately -owned new and re-
development projects that have 10,000 square feet or more of developed area are
obligated to comply with the requirements in the City of Kalispell's Standards for Design
and Construction (Kalispell 2020b), including providing water quality treatment. The
Standards provide a regulatory mechanism to address post -construction runoff from new
development and re -development, implementation of structural and non-structural
practices to minimize water quality impacts, including low impact development practices
where practicable, and ensure long-term operation and maintenance of structural
practices. The Standards have adopted in their entirety, except where amended, the
Montana Post -Construction Storm Water BMP Design Guidance Manual (HDR 2017).
Stormwater Maintenance Permit Program: The program permits post -construction water
quality treatment devices and requires yearly inspections and a five-year renewal that is
submitted by a professional engineer certifying that the structure is being maintained and
operating as designed.
14
Monitor and
e►raluate via
Stormwater
Sampling Plan
0010
Identify sub -basins
Evaluate and requiring treatment
repeat to further TIVIDL
goals
Require privately
owned new and
re -development meet
standards for
Construct CIP treatment Plan CIP
1f"
Figure 2. City of Kalispell Stormwater TMDL CIP Strategy
f-ow Impact Development
Long -Term Strategy
Assess the potential on public and private projects to reduce pollutants using low impact
development (LID) and green stormwater infrastructure, such as bio-retention swales and
dispersion (100% TSS removal). These projects allow the MS4 to increase stormwater
treatment efficiencies in larger urban watersheds and treat stormwater in smaller urban
watersheds not suitable for larger projects. Continue to evaluate ways to reduce barriers to
implementation.
BMPs
- Low Impact Development Barrier Review
15
Utilize the LID barrier review of City codes and policies to encourage implementation
and improve inconsistencies between policies. Determine barriers to City implementation
and review options for reasonable solutions.
Stormwater TMDL & Self -Monitoring
Long -Term Strategy
Collect and analyze water quality and in -stream monitoring data to understand BMP
effectiveness. Utilize adaptive management to plan future investments, education -based
initiatives, and infrastructure operations.
BMPs
- MS4 Sampling Plan for TMDL-Related Monitoring
The MS4 Sampling Plan identifies monitoring locations, strategies, and requirements for
sampling (i.e. sampling parameters, analytical methods, and quality assurance)
(Appendix C). The City performs stormwater monitoring for the following purposes
(Kalispell 2018):
• Fulfill requirements of the MS4 Permit, requiring TMDL-Related Monitoring
• Evaluate progress towards meeting the stormwater goals in the TMDL
• The City has selected TMDL-related monitoring Option 2; requiring tracking
and evaluating the effectiveness of BMPs selected for reducing MS4 loading
to impaired waterbodies (DEQ 2104)
The City has selected self -monitoring Option 2 (see Part IV of the MS4
Permit) (DEQ 2014)
4.1.3 Funding
Funding to support the stormwater program and planned actions is a challenging constraint that
is common to many programs. Sources of funding may include stormwater water quality district
fees, development fees, general funds, and/or allocations from transportation or wastewater
funds as part of specific projects.
In 2017, with City Council approval, the City increased the Storm Sewer Maintenance District
Assessment. For five years after the approval, property owners in the City will have an
assessment increase totaling 72%; 55% of which is in response to MS4 Permit requirements.
The Storm Water Facility Plan Update also includes a Financial Plan section (Kalispell 2008).
As noted in the plan, the City will need to continue analysis and monitoring of capital funding
and financing and perform a comprehensive rate analysis to provide the City with the
information necessary to determine future rate adjustments. The analysis may show that
elements of the Stormwater TMDL Action Plan may drive additional funding needs.
Other sources of funding, such as state and federal grants, may be sought to enhance the
stormwater management program.
State Grants
- Montana Renewable Resource Grant and Loan Program
16
o Funds projects for the conservation, management, development and
preservation of Montana's renewable resources
Clean Water or Drinking Water State Revolving Fund (SRF)
o Can fund capital projects
Federal Grants
- Federal Emergency Management Agency
o Examples: flood mitigation assistance and hazard mitigation grants
- Department of Commerce
o Examples: local technical assistance
- Department of Housing and Community Development
o Examples: community development block grant
- Environmental Protection Agency
o Examples: environmental justice small grants, science to achieve results,
pollution prevention, source reduction assistance, and urban small waters
grant
4.1.4 Adaptive Management
Adaptive management involves a recurring evaluation of whether actions are effective in
achieving the goals of the plan and modifying those actions as new information provides
additional insights. Findings may drive changes to the Stormwater Sampling Plan and/or the
Action Plan. To apply adaptative management, the following will be utilized:
Goal: Reduce stormwater pollutants entering impaired waterbodies.
1. Implement MS4 Sampling Plan
2. Analyze results
3. Review progress towards meeting the TMDLs
4. Adapt plans and BMPs based on results
5. Repeat
The MS4 Permit requires the TMDL section to be annually evaluated based on monitoring
results, revised as needed, and resubmitted with Annual Reports. Additionally, rationale must be
provided for changes and revisions must be approved by DEQ. Since the City has no control
over DEQ's review and approvals, and the changes are anticipated to generally be minor,
revisions will be implemented at the beginning of each year and continued unless DEQ provides
notification otherwise.
4.2 Schedule and Progress Towards Meeting the TMD'
4.2.1 Schedule for Action Items
Action items include both structural and non-structural BMPs designed to minimize the
discharge of pollutants of concern (Figure 3). Non-structural BMPs are often a part of routine
municipal operations or are a programmatic MS4 Permit component. These BMPs are utilized
throughout the year as City staff complete tasks and as public programs are administered. City
built, owned, and maintained structural BMPs are completed through the CIP process and are
17
therefore scheduled. The figure below provides the anticipated schedule for City stormwater
CIPs which are updated annually based on funds and scheduling needs.
Municipal Operations =
Figure 3. Anticipated Schedule of Structural and Non -Structural Action Items (FY = fiscal year)
4.2.2 Measuring Progress towards Meeting the TMDL
The MS4 Permit requires demonstration of progress towards satisfying the TMDL. The City has
flexibility in defining how to demonstrate progress. Although Table 2 includes numerical percent
reductions and wasteload allocations (WLAs), these values are not intended to add
concentration or load limits to the MS4 Permit. Complying with the MS4 Permit equates to
meeting the TMDL WLAs. Specifically, the TMDL states:
"Though the numeric WLAs represent a reasonable estimate of the growing
season loading after implementation of stormwater permit requirements, the WLAs
are not intended to add concentration or load limits to the permit. Consistent with
EPA guidance (U.S. Environmental Protection Agency, 2002), DEQ assumes the
WLA will be met by adhering to the permit requirements and reducing either the
total nitrogen and total phosphorus concentrations and/or the discharge volumes,
18
with the percent reduction values of 30 and 44 percent representing permit
implementation goals. As identified in the permit, monitoring data should continue
to be evaluated to assess BMP performance and help determine whether and
where additional BMP implementation may be necessary. Additional work may be
needed in the future to better identify the total nitrogen and total phosphorus
sources and BMPs already in place within the system. Also, a stormwater runoff
model (such as SWMM) would help to better estimate the load and impact from
the MS4." (DEQ 2014).
Additionally, any effort to calculate loads and percent reductions for comparison with TMDLs
and WI -As should be accomplished via the same methodology and/or models used to develop
the loads and percent reductions (DEQ 2014).
The percent reductions for total nitrogen, total phosphorus, and sediment in the TMDL were
based on average percent reduction values for a suite of BMPs provided in the TMDL (Table 4).
The TMDL based the sediment reduction value on a 2011 resource with an average sediment
reduction of 62 percent (Geo Geosyntec Consultants, Inc. et al. 2011). Literature values for total
nitrogen, total phosphorus, and sediment reduction are provided in Table 4, they include the
literature values reported in the TMDL and additional values for installed BMPs in the City's
M S4.
Table 4. DEQ TMDL Reference Pollutants of Concern Percent Removals
Structural BMP
Annual Percent Removal
Total Nitrogen
Total Phos horus
Sediment
Biofiltration Swale
40%
38%
92% 3
Bioretention
64% 2
55% 2
75% 4
Composite
n/a
n/a
79%(4)
Detention Basin
n/a
n/a
64%(4)
Dry Basin no extended detention
5% 2
15% 2
n/a
Extended Detention Dry Basin
24% 2
20% 2
n/a
Extended Detention Stormwater Wetland
25% 1
50% 1
n/a
Extended Detention Wet Pond
30% 1
50% 1
n/a
Grass Strip
n/a
n/a
57%(4)
Grass Swale
n/a
n/a
16%(4)
Hydrodynamic Separator
5% 3
18% 3
54% 3
Infiltration Basin
21% 3
47% 3
80% 3
LID
n/a
n/a
42%(4)
Media Filter
n/a
n/a
84%(4)
Porous Pavement
n/a
n/a
72%(4)
Retention Pond
n/a
n/a
75%(4)
Sand Filter
30% 1
60% 1
n/a
Vegetated Filter Strip
30% 2
60% 2
n/a
Wetland Basin
n/a
n/a
55%(4)
Wetland Basin/Retention Pond
n/a
n/a
69%(4)
Wetland Channel
n/a
n/a
23%(4)
AVERAGE
1 27%
41 %
1 62%
(1) Hirschman et al. 2008
(2) Center for Watershed Protection 2007
(3) International Stormwater BMP Database 2020
4 Geos ntec 2016
19
Non -Structural BMPs
The City implements multiple non-structural BMPs intended to reduce pollutants of concern in
the MS4 discharges. As described in Section 4.1.2, these BMPs are varied. The pollutant
reduction of some non-structural BMPs is difficult to measure, while others easily provide direct
measures. For example, measuring the pollutant reduction from a public education program is
very difficult to quantify. In contrast, infrastructure maintenance, street sweeping, and leaf
collection are trackable and provide data on the reduction of pollutants of concern.
The total mass of solids removed from treatment unit maintenance, infrastructure maintenance,
street sweeping, and leaf collection is recorded yearly in tons of solids. Total nitrogen and total
phosphorus removals are estimated from the tons of sediment and leaves collected (Table 5,
See Table A-1 in Appendix A for breakdown by BMP type).
Table 5. Summary of Pollutants of Concern Removed by Non -Structural BMPs
Year
Total Nitrogen Removed
(tons)
Total Phosphorus
Removed
tons
Sediment Removed
(tons)
2017
30.2
4.6
1303.2
2018
38.5
5.5
1456.5
2019
27.6
4.1
1102.4
2020
73.9
11.8
3440.1
Cumulative Removals
170.2
26.1
7302.2
Assuming that the activities (maintenance, street sweeping, leaf collection) are performed at an
equal rate throughout the City, the pollutant reductions per waterbody can be estimated by
determining the percent of each watershed of the City (Table 6). Since these non-structural
BMPs remove pollutants prior to discharge, the reductions should be updated annually based
on performance. The historic watershed of closed basins and the eventual discharge point of
unimpaired waters were included to evaluate total non-structural BMP pollutant reductions.
Table 6. 2020 Pollutants Removed by Non -Structural BMPs per Waterbody
Total Nitrogen
Total
Sediment
Watershed
Percentage of
Removed
Phosphorus
Removed
Total Watershed
(tons)
Removed
(tons)
tons
Ashley Creek
29%
21.4
3.4
994
Spring Creek
24%
17.4
2.8
811
Stillwater River
46%
34.1
5.5
1587
Whitefish River
1%
1.0
0.2
48
Structural BMPs
The City plans, constructs, and maintains structural water quality BMPs intended to reduce
pollutants of concern in MS4 discharges through the CIP process. Additionally, the City requires
privately owned new and redevelopment projects to include water quality treatment. Privately
owned structural BMPs are managed through the Stormwater Maintenance Permit Program
which requires annual inspections and regular maintenance. Although the City does not directly
I• •
maintain these systems, the reductions from the privately owned BMPs should be accounted for
in evaluating the progress towards meeting the Kalispell MS4 TMDLs.
The total nitrogen, total phosphorus, and sediment percent removals for each specified BMP
identified in Table 4 should be used in the accounting of progress since the TMDL used
baseline reductions of zero percent (DEQ 2014).
Since flow to each BMP is variable depending on the storm event, the BMP sub -basin area as a
proportion of the total waterbody drainage area can be used as a substitute to determine the
proportion of the total drainage flow and load treated by each BMP. This can be used to weight
the loading from each outfall. This information provides a basis for calculation of the overall
percent reduction of the total nitrogen, total phosphorus, and sediment based on the sub -basin
area and the estimated reduction efficiency of the new BMP. This is considered a comparable
method for evaluating progress toward the TMDL. An example of this analysis can be seen
below. Table 7 provides the example parameters for a BMP and the following bullets identify
how the total nitrogen, total phosphorus, and sediment reductions would be calculated for the
impaired waterbody drainage basin.
Table 7. Example Reduction Progress Evaluation for a Single BMP
BMP
BMP Reduction
BMP Reduction
BMP
BMP Drainage
stare Area
Drainage Area
Reduction in
in Total
in Sediment
Treatment
Area (acres)
(acres)
Total Nitrogen
Phosphorus
Load
Load
Load
Bioretention
10
1,000
64%
55%
75%
• Total nitrogen reduction in drainage basin: (10 acres/1,000 acres) * 64% = 0.64%
• Total phosphorus reduction in drainage basin: (10 acres/1,000 acres) * 55% = 0.55%
• Sediment reduction in drainage basin: (10 acres/1,000 acres) * 75% = 0.75%
Calculating the percent reduction becomes more complicated when one large basin is treated at
the outfall but within the basin, there are sub -basins with treatments. Some runoff in the basin
may only go through the treatment at the outfall while other runoff may go through sub -basin
treatments and then outfall treatment. Table 8 provides examples for BMP reductions for total
nitrogen, total phosphorus, and sediment calculations for an impaired waterbody drainage basin
with different levels and locations of treatment. Appendix B provides graphics illustrating the
treatment paths for the example reduction calculations.
21
Table 8. Example Reduction Progress Evaluation for Multiple Scenarios
Basin
BMP
Drainage
Area (acres)
BMP Treatment
Type
BMP
Reduction in
Total
Nitrogen
BMP
Reduction in
Total
Phosphorus
BMP
Reduction in
Sediment
Outfall Example
Outfall
1,000
Bioretention
64%
55%
75%
Net
1,000
n/a
64%
55%
75%
Sub -basin Treatment without Outfall Treatment Example
Sub -basin A
200
Bioretention
64%
55%
75%
Outfall
1,000
None
0%
0%
0%
Net
1,000
n/a
13%
11 %
15%
Sub -basin Treatment with Outfall Treatment Example
Sub -basin A
200
Bioretention
64%
55%
75%
Outfall
1,000
Hydrodynamic
Separator
5%
18%
54%
Net
1,000
n/a
17%
27%
61 %
Sub -basin within a Sub -basin Treatment with Outfall Treatment Exam le
Sub -basin B1
200
Bioretention
64%
55%
75%
Sub -basin B
400
Sand Filter
30%
60%
90%
Outfall
1,000
Hydrodynamic
Separator
5%
18%
54%
Net
1,000
n/a
25%
41 %
71 %
Two Sub -basin within a Sub -basin Treatment with Outfall Treatment Example
Sub -basin Al
100
Bioretention
64%
55%
75%
Sub -basin A
200
Sand Filter
30%
60%
90%
Sub -basin B1
200
Bioretention
64%
55%
75%
Sub -basin B
400
Sand Filter
30%
60%
90%
Outfall
1,000
Hydrodynamic
Separator
5%
18%
54%
Net
1,000
n/a
1 35%
53%
80%
The same methodology used by the TMDL for evaluating and accounting progress (and
described at the beginning of Section 4.2.2) was used to assess stormwater quality
improvements from projects in the last decade. The BMPs that have been installed in the City's
MS4 to date are identified in Appendix A. These tables identify whether the BMPs are private or
public, the discharge waterbody, and the estimated percent reduction in total nitrogen, total
phosphorus, and sediment that should be expected based on the identified BMPs.
A summary of the reduction in total nitrogen, total phosphorus, and sediment for the MS4 based
on private and public BMPs was estimated based on recent historical data (Table 9). This
analysis shows the City has made total nitrogen, total phosphorus, and sediment reductions
ranging between 3 to 14 percent. In addition to the cumulative reduction in total nitrogen, total
phosphorus, and sediment for the entirety of the watershed, Tables 10, 11, and 12 include the
cumulative reductions for each watershed individually.
22
Table 9. Reduction Progress Evaluation for Impaired Waterbodies from Structural BMPs
Cumulative
BMP
Cumulative Total
Cumulative Total
Cumulative Total
Number of
Drainage
Nitrogen
Phosphorus
Sediment
Year
BMPs
Area
Reduction
Reduction
Reduction
acres
Pre-2016
4
93
0.1 %
0.3%
1.0%
2016
17
560
1.2%
3.3%
7.3%
2017
28
601
1.3%
3.5%
7.9%
2018
41
724
1.8%
4.5%
9.8%
2019
51
811
2.1%
5.1%
11.0%
2020
1 61
1 1047
1 2.6%
1 6.6%
14.2%
Goal
I TBD
1 4891
1 30.0%
1 44.0%
62.0%
*These calculations are based on the assumption that each sub -basin with an installed structural BMP is treated
by the single BMP and does not include cumulative effects similar to those identified in Table 8. The cumulative
effects of treatment by multiple BMPs will continue to be identified and evaluated by the City in subsequent years
of analysis.
Table 10. Reduction Progress Evaluation for Ashley Creek from Structural BMPs
Cumulative
Cumulative
Cumulative Number
Cumulative
Cumulative Total
Total
Total
Year
Drainage Area
Nitrogen
of BMPs
Phosphorus
Sediment
(acres)
Reduction
Reduction
Reduction
Pre-2016
2
65
0.2%
0.8%
2.5%
2016
3
131
1.2%
3.0%
6.2%
2017
6
139
1.3%
3.2%
6.6%
2018
11
161
1.4%
3.5%
7.4%
2019
14
203
1.7%
4.1 %
9.3%
2020
16
226
1.8%
4.4%
10.1 %
Table 11. Reduction Progress Evaluation for Spring Creek from Structural BMPs
Cumulative
Cumulative
Cumulative Number
Cumulative
Cumulative Total
Total
Total
Year
Drainage Area
Nitrogen
of BMPs
(acres)
Reduction
Phosphorus
Sediment
Reduction
Reduction
Pre-2016
1
22
0.1 %
0.4%
1.1 %
2016
5
30
0.1 %
0.5%
1.4%
2017
6
30
0.1 %
0.5%
1.4%
2018
9
32
0.2%
0.5%
1.5%
2019
11
41
0.2%
0.7%
2.0%
2020
14
129
0.6%
2.0%
6.1 %
Table 12. Reduction Progress Evaluation for Stillwater River from Structural BMPs
Cumulative
Cumulative
Cumulative Number
Cumulative
Cumulative Total
Total
Total
Year
Drainage Area
Nitrogen
of BMPs
Phosphorus
Sediment
(acres)
Reduction
Reduction
Reduction
Pre-2016
1
5
0.0%
0.0%
0.1 %
2016
8
398
1.8%
4.8%
11.0%
2017
14
428
1.9%
5.2%
11.8%
2018
19
480
2.4%
6.2%
13.6%
2019
23
516
2.7%
7.0%
14.9%
2020
29
641
3.7%
9.3%
19.1 %
23
Approximately 55 to 65 percent of these reductions were from the installation of private BMPs.
Although the City permits these private installations and City engineers review the design of
these BMPs to ensure they meet City requirements and standards, the City does not plan, fund,
or install these BMPs. However, if growth and development in the City is expected to remain
constant, it can be assumed that construction and installation of privately maintained BMPs and
the resulting reduction in total nitrogen, total phosphorus, and sediment will continue at a similar
rate. This will allow flexibility in the City's planning and will reduce the capital expenditures
required by the City for installation of structural BMPs.
4.2.3 Estimation of Recent Historical Progress towards Meeting the TMDL
An estimate of the MS4's reduction of pollutants of concern from both structural and non-
structural BMPs can be made with a few assumptions. The TMDL includes an estimated load
entering the waterbodies without BMPs implemented. By using this load, the pollutant reduction
load of structural BMPs can be calculated from their associated reduction percentages. The
estimated load reductions of structural BMPs can then be combined with the current year's non-
structural BMPs' pollutant removal loads to determine the year's cumulative impact.
When pollutant reductions of structural and non-structural BMPs are combined, the cumulative
reductions surpass the MS4's WLA (Table 13). When compared, the effectiveness of non-
structural BMPs in pollutant removal is evident. However, it should be noted that pollutant
reduction for structural BMPs will always be lower since it is a percentage reduction of the
estimated load, and therefore cannot exceed the original load estimated by the TMDL.
Table 13. Estimate of Total Pollutant Reductions within the MS4 in 2020
Total Nitrogen Reduction
Ibs
Total Phosphorus
Reduction Ibs
Total Sediment Reduction
Ibs
Non-structural
147,850
23,666
6,880,100
Structural
49
8
47,084
TOTAL
147,899
23,674
6,927,184
WLA
1,030
54
156,800
Non-structural BMPs continue to be important in pollutant reduction when watersheds are
looked at separately. Figures 4, 5, and 6 show the amount of pollutants removed by both
structural and non-structural BMPs within each watershed compared to the WLA.
Ashley Creek
10,000,000
1,000,000
100,000
o 10,000
E U
N Cn
0 1,000
c�
0 100
d
10
1
Total Nitrogen Reduction (Ibs) Total Phosphorus Reduction Total Sediment Reduction
(Ibs) (Ibs)
■ Non-structural ■ Structural —WLA
10,000,000
1,000,000
100,000
o 10,000
E U
N Cn
0 1,000
c�
0 100
d
10
Figure 4. 2020 Ashley Creek Estimate of Total Pollutant Reductions
Spring Creek
Total Nitrogen Reduction (Ibs) Total Phosphorus Reduction Total Sediment Reduction
(Ibs) (Ibs)
■ Non-structural ■ Structural — WLA
Figure 5. 2020 Spring Creek Estimate of Total Pollutant Reductions
25
Stillwater River
10,000,000
1,000,000
Cn
100,000
m o 10,000
E U
N Cn
0 1,000
c�
0 100
d
10
1
Total Nitrogen Reduction (Ibs)
Total Phosphorus Reduction Total Sediment Reduction
(Ibs) (Ibs)
■ Non-structural ■ Structural — WLA
Figure 6. 2020 Stillwater River Estimate of Total Pollutant Reductions
Understanding where within the MS4 pollutant reductions are occurring and through what
mechanisms is important. As development continues, additional structural BMPs will be
incorporated, increasing their importance in overall pollutant reductions. With continued growth,
the service area of the City expands, stretching existing resources potentially making it difficult
to keep pace with non-structural BMPs. Fortunately, the City's multi -faceted approach provides
some leniency to keep pollutant reductions high while growth continues.
009
City of Kalispell I Storm Water Management Program
Stormwater TMDL Action Plan
5 References
Center for Watershed Protection. 2007. National Pollutant Removal Performance Database:
Version 3. Ellicott City, MD.
DEQ 2012. Water Quality Planning Bureau Field Procedures Manual for Water Quality
Assessment Monitoring. WQPBWQM-020. Helena, MT.
DEQ 2014. Final - Flathead — Stillwater Planning Area Nutrient, Sediment, and Temperature
TMDLs and Water Quality Improvement Plan. Document Number C11-TMDL-02aF.
Helena, MT.
DEQ 2016. General Permit for Storm Water Discharges Associated with Small Municipal
Separate Storm Sewer Systems (MS4s). Permit Number MTR040000. Montana
Department of Environmental Quality. Authorization to Discharge under the Montana
Pollutant Discharge Elimination System (MPDES). Helena, MT.
EPA 1983. Nationwide Urban Runoff Program. Accessed December 2020. {Urban Storm Water
Preliminary Data Summary (epa.gov)).
Geo Geosyntec Consultants, Inc. and Wright Water Engineers, Inc. 2011. International
Stormwater Best Management Practices Database Pollutant Category Summary: Solids
(TSS, TDS, and Turbidity). www.bmpdatabase.org.
HDR 2017. Montana Post -Construction Storm Water BMP Design Guidance Manual.
September 2017.
Hirschman, D., K Collins, and T. Schueler. 2008. Technical Memorandum: The Runoff
Reduction Method. Ellicott City, MD: Center for Watershed Protection and the
Chesapeake Stormwater Network.
Kalispell, City of. 2008. City of Kalispell. Stormwater Facility Plan Update March 28, 2008.
Prepared by HDR Engineering, Inc. and Morrison Maierle, Inc. Kalispell, MT.
Kalispell, City of. 2017. City of Kalispell, Growth Policy, Plan -It 2035. Prepared by Kalispell City
Planning Board. Adopted by Kalispell City Council, Resolution #5821A. Kalispell, MT.
Kalispell, City of. 2018. MS4 Sampling Plan for TMDL-Related Monitoring. (Appendix F:
Stormwater TMDL Action & Sampling Plan). City of Kalispell, Montana. Storm Water
Management Program. January 9, 2018.
Kalispell, City of. 2021. Stormwater Management Program. Permit Years: 2017-2021. Updated:
3/1/2021. Kalispell, MT.
Kalispell, City of. 2020b. Standards for Design and Construction. January 21, 2020.
PNAS 2018. Patterns of plant carbon, nitrogen, and phosphorus concentration in relation to
productivity in terrestrial ecosystems. PNAS April 17, 2018 115 (16) 4033-4038.
27
WERF 2017. International Stormwater BMP Database: 2016 Summary Statistics.
{https://www.bmpdatabase.org/Docs/03-SW-
1 COh%20BM P%20Database%202016%20Summary%20Stats.pdf�.
City of Kalispell I Storm Water Management Program
Stormwater TMDL Action Plan
TMDL Progress Reporting
Table A-1. Pollutants of Concern Removed by Non -Structural BMPs by Year
Year
Non -Structural BMP
Reduction in
Total Nitrogen
tons
Reduction in Total
Phosphorus
tons
Reduction
in Sediment
tons
Treatment Unit Maintenance'
0.5
0.1
22.6
Infrastructure Maintenance'
0.7
0.1
35.6
2017
Street Sweeping'
25
4.2
1,245
Leaf Collection
4.1
0.3
n/a
Treatment Unit Maintenance'
0.9
0.2
45.0
Infrastructure Maintenance'
1.0
0.2
49.5
2018
Street Swee in '
27
4.5
1,362
Leaf Collection
9.3
0.7
n/a
Treatment Unit Maintenance'
0.8
0.1
38.6
Infrastructure Maintenance'
3.0
0.5
151.8
2019
Street Sweeping'
18
3.0
912
Leaf Collection
5.6
0.4
n/a
Treatment Unit Maintenance'
1.2
0.2
59.55
Infrastructure Maintenance'
2
0.4
115.5
2020
Street Sweeping'
65
10.9
3,265
Leaf Collection z
5.1
0.4
n/a
'Total nitrogen and phosphorus estimated from tons of sediment and nutrient ratio of N 50:1 g/g and P 300 g/g (EPA 1983).
2Total nitrogen and phosphorus estimated from tons of leaves collected and nutrient stoichiometry of N 14 mg/g and P 1 mg/g
(PNAS 2018).
The total tons of leaves removed by the MS4 for the reported years is as follows: 2017 - 292 tons, 2018 - 667 tons, 2019 -
399 tons, 2020 - 366 tons
Table A-2. Pre-2016 Completed Private and Public Stormwater Quality Improvement Projects
Type and
Drainage
Discharge
BMP Total
BMP Total
BMP
Year
Name
Private or
Treatment
Location
Nitrogen
Phosphorus
Sediment
Completed
Public'
Area
Percent
Percent
Percent
acres
Remova12
Remova12
Removal'
Super One
Proprietary
Stillwater
2009
Foods
Private -
5.2
River
5%
18%
54%
HDS
South
Proprietary
2012
Meadows
Pr ivate -
36.36
Ashley
o
5 /0
0
18 /0
0
54 /o
Drainage
HDS
Creek
Improvements
Willows
Proprietary
Ashley
2013
Stormwater
Private -
28.8
Creek
o
5 /0
0
18 /0
0
54 /o
Improvements
HDS
Kalispell
Proprietary
Spring
2013
Center Mall
Private -
22.45
Creek
o
5 /0
0
18 /0
0
54 /o
HDS
'Propriertary means manufactured control measure or devices with a company branded treatment process.
2Percent removal based on Table 5-21 DEQ 2014
3Average percent removal based on Section 6.5.5.2 DEQ 2014, treatment specific percent removal based on
WERF 2017
Referenced percent removals summarized in Table 4
Table A-3. 2016 Completed Private and Public Stormwater Quality Improvement Projects
Private
Type'
Drainage
Discharge
BMP
BMP Total
BMP
or
Treatment
Location
Total
Phosphorus
Sediment
Name
Public
Area
Nitrogen
Percent
Percent
(acres)
Percent
Removal2
Removal'
Removal2
Sylvan Drive
Public
Proprietary
265
Stillwater
5%
18%
54%
2
River
Spring Creek
Structure
Alley
Public
Sump
0.05
Spring Creek
0%
0%
0%
Stormwater
Spring Prairie
Private
Infiltration
56
Closed Basin
o
21 /0
0
47 /0
0
80 /o
Four
Basin
.53
(Stillwater)
Gardner
Infiltration
Closed Basin
Retention
Private
Basin
66.26
(Lower
21%
47%
80%
Ashley)
Owl View
Private
Infiltration
046
Closed Basin
47%
80%
Townhomes
Basin
.
Stillwater)21%
Glacier View
Closed Basin
Professional
Private
Proprietary
0.567
(Stillwater)
5%
18%
54%
Center
Herberger's
Private
Proprietary
Spring Creek
5%
18%
54%
Expansion
Hampton Inn
Private
Proprietary
6.75
Spring Creek
5%
18%
54%
McDonald's
Private
Proprietary
0.92
Spring Creek
5%
18%
54%
Proprietary &
Forest Service
Private
Wet
0.39
Stillwater
30%
50%
64%
Building
Detention
River
Basin
J2 Office
Private
Proprietary
0.21
Stillwater
5%
18%
54%
Warehouse
River
KRH Northwest
Private
Infiltration
061
Closed Basin
47%
80%
FamilyMedicine
Basin
.
(Whitefish)21%
Sunnyview
Proprietary &
Closed Basin
Phase I I I
Private
Infiltration
69.15
(Stillwater)
o
21%
0
47 /0
0
80 /o
Basin
'Propriertary means manufactured control measure or devices with a company branded treatment process.
2Percent removal based on Table 5-21 DEQ 2014
3Average percent removal based on Section 6.5.5.2 DEQ 2014, treatment specific percent removal based on
WERF 2017
Referenced percent removals summarized in Table 4
Table A-4. 2017 Completed Private and Public Stormwater Quality Improvement Projects
Private
Type'
Drainage
Discharge
BMP
BMP Total
BMP
or
Treatment
Location
Total
Phosphorus
Sediment
Name
Public
Area
Nitrogen
Percent
Percent
(acres)
Percent
Removal2
Removal'
Removal2
41h Avenue E
Water
Public
N/A
N/A
Ashley and
o
0 /0
0
0 /0
0
0 /o
Replacement
Stillwater
Begg Park Dog
Public
Infiltration
1.69
Ashley Creek
21%
47%
80%
Park
Basin
MDT
Maintenance
Public
Proprietary
1.6
Stillwater
5%
18%
54%
Facility — City
River
Maintained
Southside
Private
Proprietary
5.8
Ashley Creek
5%
18%
54%
Estates
2
Glacier Village
Infiltration
Closed Basin
Greens Phase
Private
Basin
2.75
(Whitefish)
21%
47%
80%
21
RDO
Private
Bioretention
0.37
Ashley Creek
64%
55%
75%
Pinnacle
Infiltration
Closed Basin
Chiropractic
Private
Basin
0.28
(Spring
21%
47%
80%
Creek
Owl View
Infiltration
Closed Basin
Landing
Private
Basin &
3.923
(Stillwater)
21%
47%
80%
Proprietary
Emmanuel
Proprietary
Stillwater
Lutheran West
Private
(2)
4.74
River
5%
18% 0
54%
Campus
Kalispell Ford
Private
Infiltration
10
Closed Basin
21%
47%
80%
Basin
(Stillwater)
Women's &
Private
Proprietary
3.58
Closed Basin
5%
18%
54%
Children's
Stillwater
MDT
Proprietary
Stillwater
Maintenance
Private
(2)
6.2
River750%
18/0 054
/o0
Facility
'Propriertary means manufactured control measure or devices with a company branded treatment process.
2Percent removal based on Table 5-21 DEQ 2014
3Average percent removal based on Section 6.5.5.2 DEQ 2014, treatment specific percent removal based on
WERF 2017
Referenced percent removals summarized in Table 4
Table A-5. 2018 Completed Private and Public Stormwater Quality Improvement Projects
Private
Type'
Drainage
Discharge
BMP
BMP Total
BMP
or
Treatment
Location
Total
Phosphorus
Sediment
Name
Public
Area
Nitrogen
Percent
Percent
(acres)
Percent
Removal2
Removal'
Removal2
Glacier Rail
Proprietary &
Park
Public
Infiltration
47.724
Closed Basin
21%
47%
80%
Basin
Sherry Lane
Storm
and Ramsgate
Public
Improvements
N/A
Spring Creek
0%
0%
0%
Dr.
& Flood
Reduction
The Vision
Private
Proprietary
0.75
Spring Creek
5%
18%
54%
Clinic
Peterson
Infiltration
Closed Basin
Elementary
Private
Basin
0.12
(Lower
21%
47%
80%
Ashley)
J2 Office
Private
Proprietary
0.79
Stillwater
5%
18%
54%
Products
River
Glacier Rail
Private
Infiltration
44
Closed Basin
47%
80%
Park
Basin
.07
(Stillwater)21%
Infiltration
Closed Basin
PTA
Private
Basin
0.798
(Lower
21%
47%
80%
Ashley)
First American
Private
Proprietary
0.74
Stillwater
5%
18%
54%
Title
River
Husky Street
Private
Biofiltration
0.83
Spring Creek
40%
38%
92%
Apartments
Swale
Green
Closed Basin
Nissan/Hyundai
Private
Proprietary
6.2
(Lower
5%
18%
54%
Ashley)
Rankin
Private
Proprietary
11.62
Ashley Creek
5%
18%
54%
Elementary
Lofts at Ashley
Private
Proprietary
3.7
Ashley Creek
5%
18%
54%
Treeline
Private
Proprietary
5.603
Stillwater
5%
18%
54%
Subdivision
River
'Propriertary means manufactured control measure or devices with a company branded treatment process.
2Percent removal based on Table 5-21 DEQ 2014
'Average percent removal based on Section 6.5.5.2 DEQ 2014, treatment specific percent removal based on
WERF 2017
Referenced percent removals summarized in Table 4
Table A-6. 2019 Completed Private and Public Stormwater Quality Improvement Projects
Private
Type'
Drainage
Discharge
BMP
BMP Total
BMP
or
Treatment
Location
Total
Phosphorus
Sediment
Name
Public
Area
Nitrogen
Percent
Percent
(acres)
Percent
Removal2
Removal'
Removal2
Sylvan Drive
Extended
Conveyance
Public
Detention
N/A
Stillwater
24%
20%
64%
and Detention
Basin
(refurbish)
River
Improvements
Shop Complex
Proprietary
Pavement
Public
(2)
26.82
Ashley Creek
o
5%
0
18 /0
0
54 /o
Restoration
Linderman
Public
Proprietary
3.49
Ashley Creek
5%
18%
54%
School
Faith Covenant
Public
Proprietary
2.92
Ashley Creek
5%
18%
54%
Presbyterian
Brightview
Private
Infiltration
3216
Stillwater
o
21 /0
0
47 /0
0
80 /o
Subdivision
Basin
.
River
Oral Surgery
Private
Infiltration
0.588
Closed Basin
21%
47%
80%
Basin
(Stillwater)
Edge
Private
Biofiltration
0.42
Spring Creek
40%
38%
92%
Apartments
Swale
Basecamp RV
Private
Biofiltration
9.24
Ashley Creek
40%
38%
92%
Swale
Glacier Eye
Private
Infiltration
3.42
Stillwater
21 %
47%
80%
Clinic
Basin
River
Meadows Edge
Private
Proprietary
8.424
Spring Creek
5%
18%
54%
Phase 1A
'Proprietary means manufactured control measure or devices with a company branded treatment process.
2Percent removal based on Table 5-21 DEQ 2014
3Average percent removal based on Section 6.5.5.2 DEQ 2014, treatment specific percent removal based on
WERF 2017
Referenced percent removals summarized in Table 4
Table A-7. 2020 Completed Private and Public Stormwater Quality Improvement Projects
Private
Type'
Drainage
Discharge
BMP
BMP Total
BMP
or
Treatment
Location
Total
Phosphorus
Sediment
Name
Public
Area
Nitrogen
Percent
Percent
(acres)
Percent
Removal2
Removal'
Removal2
Fresh Life
Public
Proprietary
1.8
Ashley Creek
5%
18%
54%
Smith's Grocery
Private
Proprietary
4.37
Stillwater
5%
18%
54%
4
River
Southside
Private
Proprietary
20.5
Ashley Creek
5%
18%
54%
Estates Phase 2
2
Glenwood
Private
Proprietary
5.58
Spring Creek
5%
18%
54%
Apartments
Jaxon Ridge
Private
Proprietary
3.896
Dry Bridge
5%
18%
54%
Slough
Peterson Acre
Private
Infiltration
1
Closed Basin
21%
47%
80%
Basin
(Stillwater)
Kalispell North
Private
Infiltration
102
Closed Basin
o
21/0
0
47 /0
0
80 /o
Town Center
Basin
(Stillwater)
Westview
Private
Proprietary
13.0001
Closed Basin
5%
18%
54%
Phase 4
Stillwater
Cottage
Gardens
Private
Proprietary
11.7
Spring Creek
5%
18%
54%
Meadow's Edge
Private
Proprietary
71.27
Spring Creek
5%
18%
54%
Owl View
Private
Proprietary
0.988
Closed Basin
5%
18%
54%
LandingStillwater
'Proprietary means manufactured control measure or devices with a company branded treatment process.
2Percent removal based on Table 5-21 DEQ 2014
3Average percent removal based on Section 6.5.5.2 DEQ 2014, treatment specific percent removal based on
WERF 2017
Referenced percent removals summarized in Table 4
City of Kalispell I Storm Water Management Program
Stormwater TMDL Action Plan
Treatment Scenarios
Corresponding to nitrogen removal and scenarios in
Table 8
Total
t
Total Basin - 1,000 ac 1,000 ac basin with 200
ac sub -basin. Sub -basin
has bioretention treatment
at the effluent.
13% Reduction
Sub -basin A
200 ac
BR
y
l �
72 ac J —
Bioretention = 64% removal 8j2
a�
200 ac -200 ac x 64% = 72 ac
ab
1000 ac - 200 ac + 72 ac =872 ac
1,000 ac basin with 200 ac
sub -basin. Sub -basin has
bioretention treatment at the effluent.
Total Basin = 1,000 ac Entire basin has hydrodynamic
separator treatment at the effluent.
17% Reduction
Sub -basin A Al
200 ac
y `
72 ac J -
Bioretention = 64% removal r 8j2
0,
200 ac - 200 ac x 640 = 72 ac
1000 ac - 200 ac + 77c,=872ac
Hydrodynamic separator = 5% removal
872 ac - 872 ac x 5% = 828 ac
Total Basin = 1,000 ac Sub -basin B1
200 ac
Bioretention = 64% removal
Sub -basin B 200 ac - 200 ac x 64% = 72 ac
400 ac °a
400 ac - 200 ac + 72 ac = 272
1,000 ac basin with 400 ac sub -basin with
filter at the effluent. Sub -basin also has a
200 acre sub -basin with bioretention
treatment at the effluent. Entire basin has
hydrodynamic separator treatment at the
effluent.
25% Reduction
BR,,72q
aC
190 ac
1000 ac - 400 ac + 190 ac = 790 ac
Filter = 30% removal
272 ac - 272 ac x 30% = 190 ac
A
#d e
Hydrodynamic separator = 5% removal SJ
01
790 ac - 790 ac x 5% = 751 ac
1,000 ac basin with two sub -basins, A & B. Sub -basin A is 200 acres with a filter at the effluent.
Sub -basin A also has a 100 acre sub -basin with bioretention at the effluent. Sub -basin B is 400
acres with a filter at the outlet. Sub -basin B also has a 200 acre sub -basin with bio-retention at the
effluent. The entire basin also has a hydrodynamic separator at the effluent.
35% Reduction
Total Basin = 1,000 ac
Sub -basin B
400 ac
Sub -basin A •.l�
200 ac
Sub -basin Al P
100 ac
1 a
BR +,_36 ac>
Sub -basin B1
200 ac
Bioretention = 64% removal
0
200 ac - 200 ac x 64% = 72 ac
a
400 ac - 200 ac + 72 ac = 272
BR -*
Filter = 30% removal
22
--� _,
2j2ac
272 ac - 272 ac x 30%
= 190 ac
136 ac
190 ac
— 6,9,6
l
95 ac J
ac
Bioretention = 64% removal
100ac-100acx64%E36
200 ac - 100 ac = 136 ac
Filter = 30% removal
136ac- 136ac x30%=95ac
1000 ac - 400 ac - 200 ac + 190 ac + 95 ac = 685 ac
Hydrodynamic separator = 5% removal
685 ac - 685 ac x 5% = 651 ac
TMDL Sampling Plan
A?UNTAN: 1
Ih
Prepared by
MS4 Sampling Plan
for TMDL-Related
Monitoring
City of Kalispell, Montana
Storm Water Management Program
January 9, 2018
This page intentionally left blank
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
Table of Contents
1 Introduction.....................................................................................................................................1
1.1. Background.............................................................................................................................1
1.2. Purpose...................................................................................................................................1
2 Kalispell MS4-Related TMDLs.......................................................................................................1
2.1. TMDL Overview......................................................................................................................1
2.2. TMDL Strategy........................................................................................................................2
3 Monitoring Locations and Strategies..............................................................................................2
3.1. Sites 001 and 001 a: Hydrodynamic Separator Effectiveness Evaluation ..............................2
3.2. Site 002: Assess Future BMP Performance in Commercial/ Industrial Area.........................3
3.3. Site 004: Assess Future BMP Performance in Residential Area...........................................4
4 Monitoring Requirements...............................................................................................................6
4.1. Field Sampling Methods.........................................................................................................6
4.2. Sampling Parameters and Analytical Methods......................................................................7
4.3. Sample Handling and Documentation....................................................................................7
4.4. Storm Events and Sample Frequency....................................................................................8
4.5. Quality Assurance/Quality Control..........................................................................................9
4.6. Analysis of Results................................................................................................................9
5 Reporting........................................................................................................................................9
Figure 1. Monitoring Sites 001 and 001a
Figure 2. Monitoring Site 002..................
Figure 3. Monitoring Site 004..................
Figures
Tables
Table 1. Summary of TMDLs with Kalispell MS4 Approved WLAs
Table 2. TMDL-Related Monitoring Sample Locations ...................
Table 3. Self -Monitoring Sample Locations ....................................
Table 4. Analytical Methods............................................................
Appendices
Appendix A —Supplemental Figures
3
4
5
2
5
6
8
January 9, 2018
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
1 Introduction
BaCKground
The City of Kalispell (City) operates its storm drainage system under the authorization of the
Montana Pollution Discharge Elimination System (MPDES) General Permit for Storm Water
Discharges Associated with Small Municipal Separate Storm Sewer Systems (MS4s), hereafter
referred to as the MS4 General Permit. The current MS4 General Permit, issued by the Montana
Department of Environmental Quality (MDEQ), is effective from January 1, 2017 through December
31, 2021.
In accordance with Part III of the MS4 General Permit, the City is required to develop a sampling
plan for total maximum daily load (TMDL) related monitoring, due with the first year's annual report;
and a TMDL section in its Storm Water Management Program (SWMP), due with the fourth year's
annual report. The results from the TMDL-related monitoring will be used in conjunction with the
TMDL section of the SWMP to address applicable TMDLs. Similarly, Part IV of the MS4 General
Permit requires semi-annual monitoring (self -monitoring) that may be satisfied entirely or in part by
the TMDL-related monitoring required under Part III.
1.2. Purpose
The purpose of this sampling plan is to describe the City's TMDL-related monitoring program for the
2017 through 2021 permit term. More specific details relating to the purpose of this plan are as
follows:
■ The City has selected TMDL-related monitoring Option 2; therefore, this plan will be
implemented to track and evaluate effectiveness of BMPs selected for reducing MS4 loading
to impaired waterbodies.
■ In accordance with the MS4 General Permit requirements, this plan will ultimately become a
part of the TMDL section of the City's SWMP (which will be submitted with the fourth year's
annual report in 2020).
■ The City has selected self -monitoring Option 2 (see Part IV of the MS4 General Permit). The
monitoring locations identified in this plan will also be used to fulfill the self -monitoring
requirements. Additional discussion on the City's plan for self -monitoring is provided in
Section 8 of the City's SWMP.
■ This document, when implemented, will fulfill the requirements of Part 111.13 of the MS4
General Permit, requiring a sampling plan for TMDL-Related Monitoring.
2 Kalispell MS4-Related TMDLs
M . TMDL Overview
There are six named or perennial surface waters that receive stormwater discharges from the City's
MS4 outfalls. These receiving waters are as follows:
■ Whitefish River
■ Stillwater River
■ Ashley Creek
January 9, 2018
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
Spring Creek
Bowser/Little Spring Creek- Aka Kids Creek -Classified as an unnamed perennial
Unnamed perennial surface water tributary to Ashley Creek from Foys Lake
The Whitefish River, Stillwater River, Spring Creek, and Ashley Creek are classified as impaired
surface waters of the state and each has an approved pollutant TMDL with waste load allocation
(WLA). Table 1 summarizes the impaired waterbodies with TMDLs within the Kalispell MS4
boundary and the associated pollutant of impairment. Figure A.1 (Appendix A) provides a map of the
City's outfalls and associated receiving waterbodies.
Table 1. Summary of TMDLs with Kalispell MS4 Approved WLAs
Waterbody
Whitefish River X
Stillwater River X _
Spring Creek X X X
Ashley Creek' X X X X
TN is a surrogate TMDL for Nitrate+Nitrite
' Middle and Lower Segments
2.2. TMDL Strategy
Part III.B of the MS4 General Permit specifies that the City shall develop and implement a section of
their SWMP to address TMDLs. More specifically, the City must include in its SWMP a section
identifying the measures and BMPs it plans to implement, describing the City's impairment priorities
and long term strategy, and outlining interim milestones (i.e., a completion schedule for action items)
for controlling the discharge of the pollutants of concern and making progress towards meeting the
TMDL. The City has yet to develop this section of the SWMP; however, the City has selected its
monitoring locations in watersheds where they are currently planning to implement BMPs aimed at
reducing pollutants of impairment for its receiving waterbodies. Additional discussion of target
pollutants and impairment priorities will be provided within the TMDL section of the SWMP when it is
submitted.
3 Monitoring Locations and Strategies
3.1. Sites 001 and 001 a: Hydrodynamic Separator Effectiveness
Evaluation
The City installed a Downstream Defender® hydrodynamic separator in August 2016 near the
intersection of Sylvan Drive and Sylvan Court (see Figure 1). This area drains to the Stillwater River,
which has an MS4 WLA for sediment. The City will conduct monitoring immediately upstream and
downstream of the hydrodynamic separator in order to evaluate its effectiveness at removing
sediment from MS4 wet weather discharges. Additional parameters will also be analyzed in
accordance with Table 1. Small MS4 Monitoring Requirements, of Part N.A. in the MS4 General
Permit.
January 9, 2018
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
The results of this evaluation will be used to assist the City in making informed decisions about
whether to install a Downstream Defender° hydrodynamic separator, or equivalent device, in other
locations.
� LLV LIY V//
l
i
Figure 1. Monitoring Sites 001 and 001a
�.�. Site 002: Assess Future BMP Performance in Commercial/
Industrial Area
Kalispell MS4 drainage area SWR-7 drains to the Stillwater River, which has an MS4 WLA for
sediment. A monitoring location is located near the outfall of this watershed on Wyoming Street (see
Figure 2). The drainage area is approximately 100 acres, comprised mostly of commercial/industrial
land use. The City is planning to implement future BMPs within this drainage area in an effort to
reduce the MS4's discharge of sediment to the Stillwater River. The monitoring results from samples
collected before the BMPs are implemented within the drainage area (baseline samples) will
establish the existing conditions. Future monitoring results will be compared to the baseline samples
as BMP(s) are added within the drainage basin. The City plans to use the monitoring data results
from this site to assess the BMP effectiveness in this immediate watershed (drainage area SWR-7)
and develop a plan for installing BMPs in other commercial/industrial areas.
January 9, 2018 3
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
LEGEND
Monitoring Location
Receiving Waterbody
Figure 2. Monitoring Site 002
Site 004: Assess Future BMP Performance in Residential
Area
Kalispell MS4 drainage area AC-11 drains to Ashley Creek, which has an MS4 WLA for phosphorus,
nitrogen, dissolved oxygen, sediment, and temperature. A monitoring location is located near the
outfall of this watershed on 11t" Street West (see Figure 3). The drainage area is approximately 300
acres, comprised mostly of residential land use. The City is planning to implement future BMPs
within this drainage area in an effort to reduce the MS4's discharge of pollutants to Ashley Creek.
The monitoring results from baseline samples collected within the drainage area will establish the
existing conditions. Monitoring results will be compared to the baseline data as BMP(s) are added
within the drainage basin. The City plans to use the results of the monitoring data at this site to
assess BMP effectiveness in this immediate watershed (drainage area AC-11) and plan future BMPs
in other residential areas.
A summary of all TMDL-related monitoring locations is provided in Table 2. For reference, Table 3
provides a summary of all self -monitoring locations where sampling will be conducted in accordance
with Part IV of the MS4 General Permit. Comparison of Table 2 and Table 3 reveals that three of the
self -monitoring locations will also be used for TMDL-related monitoring. This allows the City to be
more efficient with collection of samples and analysis of monitoring data each year.
January 9, 2018 4
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
a
L
O Storm Manhole
• Monitoring Location
Storm Main
------- Open Channel or Ditch
Receiving Waterbody
Figure 3. Monitoring Site 004
Table 2. TMDL-Related Monitoring Sample Locations
001 SWR-4 Stillwater
48°11'40.14"N Grab 4 Sediment
River
114°17'55.76"W
Stillwater
48°11'40.70"N
001a SWR-4
River
Grab 4 Sediment
114°17'57.38"W
002 SWR-7 Stillwater
48°12'26.98"N Grab' 4 Sediment
River
114'18'49.81"W
004 AC-11 Ashley 48'11'10.01"N Grab' 4 TP, TN, DO, Sediment,
Creek 114°19'17.46"W Temperature
' A composite sample is the preferred sample collection method for this site; however, experience collecting grab
samples at this site will help the City develop a better understanding of site conditions resulting in a more effective
implementation plan and design for collecting composite samples in the future. The City will consider development of a
composite sample collection and analysis plan for this site in the coming years.
January 9, 2018 5
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
Table 3. Self -Monitoring Sample Locations
Name Watershed Receiving Locatio
Waterbody
Stillwater
48°11'40.14"N
001 SWR-4
River
114°17'55.76"W
00 SWR-7
Stillwater
48°12'26.98"N
River
114'18'49.81"W
003-A AC -A Ashley 48°11'43.49"N
Creek 114°22'23.71 "W
004 AC-11 Ashley 48'11'10.01"N
Creek 114°19'17.46"W
Grab Semi-annual'
■ Total Suspended Solids
■ Chemical Oxygen Demand
Grab Semi-annual' - Total Phosphorus
■ Total Nitrogen
■ pH
■ Copper
Grab Semi-annual' - Lead
■ Zinc
■ Estimated Flow
■ Oil and Grease
Grab Semi-annual'
' One sample must be collected between January 1It and June 30th of each permitted calendar year and the other
sample between July 15t and December 315c
4 Monitoring Requirements
Quality Assurance/Quality Control (QA/QC) is critical for accurate sampling. This section provides
details of sampling methods, laboratory analytical methods, and QA/QC procedures to be used in
sampling.
4.1. Field Sampling Methods
The City will use manual sample collection techniques to conduct monitoring activities at each site in
the immediate future. In the coming years, automated samplers will likely be used to collect
composite samples at sites 002 and 004. Each of these methods are discussed below.
4.1.1 Manual Sample Collection
Manual grab techniques will be used to collect samples at 001, 001 a, and 003' throughout the
duration of this plan. The grab sample method is suitable for site's 001 and 001 a because samples
will be collected within minutes of each other and since the hydraulic residence time that stormwater
is in the BMP is only a few minutes, this approach will provide an accurate comparison of influent
and effluent water quality for the Downstream Defender° hydrodynamic separator. A grab sample at
site 003 will be used to evaluate the quality of water in Ashley Creek upstream of Kalispell's MS4.
Manual grab techniques will also be used to collect samples at sites 002 and 004 in the immediate
future; however, the City is considering the use of automated samplers to collect composite samples
at these sites in the coming years (see Section 4.1.2).
The samples will be collected by field personnel during rainfall events. Rainfall events will be
monitored by weather surveillance radar so that field personnel can determine when to be present in
the watershed during active events to obtain manual samples.2 Samples will be collected in clean,
' Site 003 is a self -monitoring site and will not be part of the TMDL-related monitoring.
2 Radar is available via the Nation Weather Service webpage
https://radar.weather.gov/ridge/radar.php?rid=msx&product=NOR&overlav=l 1101111 &loop=no
January 9, 2018
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
labeled bottles provided by the laboratory. If necessary, an extension pole, rope or other apparatus
can be used to aid the field crew in safe sample collection, especially during high flow conditions.
4.1.2 Automated Sample Collection
If applicable, automated sampling devices will be used to collect composite samples; that is, small
constant volume samples that are collected throughout a runoff event (as opposed to a manual grab
sample, which only represents one point in time during an event). The City owns two ISCO 6712
automated sample devices which will likely be used to collect composite samples at site's 002 and
004 in the future.
The primary monitoring objective at site's 002 and 004 is to assess the impact of future BMPs
implemented upstream using sample data collected near the downstream -most point in a local
watershed. Composite sampling is preferred for these locations because it would provide an event
mean concentration of the pollutants from the runoff event; however, as noted above, additional
experience and understanding of site conditions is needed to effectively and accurately collect and
analyze composite samples.
If automated sampling is implemented, the City expects that flow -weighted sampling would be used
by collecting multiple aliquots (small samples) over the duration of the storm in one bottle which will
be shipped to the Montana Environmental Laboratory for analysis following the storm event.
4.1.3 Sampling Equipment Decontamination
Decontaminated sample collection bottles and lids will be provided by the laboratory.
Sampling Parameters and Analytical Methods
The water quality samples collected will be analyzed for the MS4 listed pollutants of impairment in
the specific receiving waterbody as well as the parameters listed in Table 1 of Part IV.A in the MS4
General Permit (Small MS4 Monitoring Requirements). Table 4 shows the parameters and standard
analytical methods to be used.
All data should meet the precision, recovery, and accuracy requirements specified in the laboratory
method used. The laboratory used for this study will maintain internal quality assurance/quality
control procedures as documented in their laboratory quality assurance manual. The laboratory will
use a combination of blanks, laboratory control spikes, surrogates, and duplicates to evaluate the
analytical results.
Sample Handling and Documentation
Automatic samplers will be serviced immediately following a storm event. Chain of custody forms will
accompany all samples. A Field Log will be kept for each sampling site with the details of the date,
time, personnel, and purpose of visit, weather, and conditions observed, samples collected and
actions performed.
January 9, 2018
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
Table 4. Analytical Methods
Total Suspended
SM 2540 D
1
Solids
Total Phosphorus
E365.1
0.01
Nitrogen — Kjeldahl,
E351.2
0.2
total'
Nitrate & Nitrite,
E353.2
0.01
total'
E300A
1 L plastic3
None
Chemical Oxygen
E410.1
1
Demand
E410.4
Total Recoverable
E200.8
0.01
Copper2
Total Recoverable
E200.8
0.001
Lead2
Total Recoverable
E200.7
0.01
Zinc2
E200.8
Oil and Grease2
E1664A
1
1 L glass (2)
H2SO4 to pH<2
Cool to 4°C
Estimated Flow2
N/A
N/A
N/A
N/A
Dissolved Oxygen
SM 4500-OG
0.1
N/A
N/A
Temperature
N/A
0.1°C
N/A
N/A
Analyze
immediately3
28
Analyze
onsite4
Analyze
onsite4
Analyze
onsite4
PH E150.1 0.1 unit N/A N/A Analyze
onsite
' Total Nitrogen is calculated from Nitrogen — Kjeldahl, total and Nitrate & Nitrite, total.
2 These parameters will only be analyzed semi-annually, in accordance with the City's self -monitoring plan.
3 Samples will be immediately delivered to the Montana Environmental Lab in Kalispell. The lab staff will
separate the 1 L samples so that each parameter can be analyzed. Preservatives will be added by the lab
staff, if necessary.
4 The City analyze for estimated flow, dissolved oxygen, temperature, and pH, onsite.
4.4. Storm Events and Sample Frequency
Sampling will be attempted for measurable runoff events (that is a rainfall events that produce any
volume of runoff flowing past/through the monitoring location that will allow a sample to be
collected). In accordance with Part IV.a.6.a. of the MS4 General Permit, a minimum of one sample
will be collected at each site between January 1 st and June 30th and a minimum of one sample will
be collected at each site between July 1 st and December 31 st of each year. The City will attempt to
January 9, 2018 8
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
collect four samples annually for MS4 listed impairments at each site (see Table 2).3 Four annual
samples will provide greater assurance that data is representative.
Precipitation will be monitored using a combination of on -site or web -based rain gauge s4, and the
radar managed by the National Oceanic and Atmospheric Administration's Nation Weather Service.
This data may be used to delineate storm characteristics, if necessary (timing, duration, intensity,
and relative total rainfall).
4.5. Quality Assurance/Quality Control
Samples will be analyzed using the designated EPA Method or Standard Method as defined in Table
4. Chain -of -custody procedures will be followed for samples sent to the laboratory.
Analysis of Results
All sample results will be compiled into a spreadsheet containing the results for each parameter at
every sample site. The analysis method will vary depending on the sample collection method and
site objectives, which are described in the subsequent sections.
4.6.1 Sample Collection at Sites 001 and 001a
The objective at sample site's 001 and 001 a is to compare influent and effluent data for the
Downstream Defender° hydrodynamic separator. BMP effectiveness will be quantified by calculating
the percent change in pollutant concentration between the two sample sites, using Equation 1. The
calculated percent change for each sample collected will be presented on a graph (sample date vs.
percent change) to assess the long-term performance of the BMP.
mim
Percent Change= C'cce *100 Equation 1
C; = Influent concentration (mg/L)
Ce = Effluent concentration (mg/L)
4.6.2 Sample Collection at Sites 002 and 004
A graph will be generated showing sample date (time) vs. concentration, for each parameter. These
graphics will show the trend in water quality data over the period of time which samples are being
collected. A downward trend will indicate that BMPs implemented upstream are effective, while a
stagnant or upward trend would indicate the BMPs implemented upstream are not effective at
reducing pollutants. A separate analysis of each parameter can be used to help understand the
effectiveness of BMPs for a variety of parameters considered.
5 Reporting
The results from TMDL-related monitoring will be presented and discussed in each year's MS4
annual report. The discussion will focus on the evaluation of the effectiveness of BMPs being
implemented to address pollutants of impairment within each local watershed as well as changes in
water quality over time.
3 Only two of the four annual samples will be analyzed for the full suite of self -monitoring parameters
(listed in Table 1. Small MS4 Monitoring Requirements, of Part IV.A. in the MS4 General Permit).
4 The following websites provide historic rainfall data for the City of Kalispell:
http://w2.weather.gov/climate/index.php?wfo=mso;
http://mesowest.utah.edu/cqi-bin/droman/precip monitor.cgi?state=MSO&rawsflaq=3
January 9, 2018
City of Kalispell I Storm Water Management Program
MS4 Sampling Plan for TMDL-Related Monitoring
Appendix A. Supplemental Figures
LEGEND
Outfall
Storm Main
Kalispell Receiving Waterbo(
. City Limits
Approximate Drainage Basin*
Ashley Creek
Little Spring Creek
Spring Creek
Stillwater River
Unnamed Perennial
Whitefish River
Areas which Generally Drain
to an Infiltration Basin
*Note: Drainage basin delineations
are approximate and only consider
areas within the city limits. These
delineations are intended to generally
depict which waterbodies portions of
the MS4 drains to.
0 Feet 4,000
DATA SOURCE: ESRI, City of Kalispell
..
r..
1
1
1
1
1 j
1
1
FN
77 G:IPROJECTSIKALI SPELLIKALI SPELL MS4IMAP DOCSIFK URE I -RECENING WATERBOOIES MAP.MXO - USER: MPETERSO - DAM 10291201;
\
LEGEND
Monitoring Location
Outfall
Storm Main
e
— Kalispell Receiving Waterbody
v City Limits
Approximate Drainage Basin*
Ashley Creek
Little Spring Creek
Spring Creek
- Stillwater River
Unnamed Perennial
' Whitefish River
®Areas which Generally Drain to
an Infiltration Basin
*Note: Drainage basin delineations
are approximate and only consider
areas within the city limits. These
delineations are intended to generally
depict which waterbodies portions of
the MS4 drains to.
0 Feet 4,000
DATA SOURCE: ESRI, City of Kalispell
Site 002 - TMDL & Self -Monitoring Lc
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PATH: S:IPW OATAIOEPARTMENTS%STORMWATER%PHASE 11 STORM WATER PERMITSTORMWATER MANAGEMENT PROGRAMISTORM SAMPLING%EOITABLE OOCUMENTSTIGURE 2 - MONITORING LOCATIONS MAP UPOAMMXO - USER: CLEW I S - OATS: 11912020