stormwater management challenges and opportunities

Stormwater Management Challenges and Opportunities

Agenda

• Other State Programs

• Case Studies– Spokane County– Ada County (Boise)

• Links to TMDLs

7 Areas Listed in Montana

• Montana– Billings, Yellowstone County, and MDT– Great Falls, Cascade County, and MDT– Missoula, Missoula County, and U of M and

MDT– Bozeman, MSU and MDT– Helena– Kalispell and MDT– Butte and MDT– MDT in Helena

Montana listed those over 10,000 people with 303 (d) listed streams and areas that met population densities.

3 Areas Listed in Wyoming

• Wyoming– Cheyenne– Casper– Sheridan (pending)

• Idaho– Boise (Phase 1 City)– Pocatello– Idaho Falls– Many others

Wyoming listed those over 10,000 people with data showing an impact of the system on water quality

Idaho is giving individual MS4 permits rather than a General Permit

Washington

• Published permit in 2007

• Cities appealed

• Resolved in 2008

• First annual reports due in 2009

• Separated into East/West

Washington listed cities with more than 10,000 population and 303(d) listing

Washington Permit

• “The SWMP shall reduce pollutants to the Maximum Extent Practicable (MEP) …and to apply All Known, Available, and Reasonable methods of preventional control and Treatment (AKART) prior to discharge to protect water quality”

Requires Consideration of Low Impact Development Techniques

• LID consideration is required

• More prescriptive language overall

• Must document how BMPs are selected

• Expected Performance

• DOE provides BMP manuals

• Field Surveys required

• Annual Reporting Forms

Monitoring in Washington

• Each City must designate two sites for “effectiveness monitoring”

• Submit a monitoring plan

• No numeric targets included

Ada County Highway District (Boise Area)

• $700,000 operating budget (250,000 people)• Does not include capital programs• Funded out of the general fund• 5 FTEs• Audited by Region 10 EPA in 2008• Settlers Irrigation Lawsuit filed in 2009

– Basis of the claim is water quality degration from City stormwater

– Pioneer Irrigation District has sued the City of Caldwell as well

Ada County Highway District (Boise Area)

• TMDL highlights Phosphorous, Bacteria and Sediment

• BMPs are chosen based on these needs

• IDEQ has issued a broad manual

• Homeowners associations are responsbile for maintenance (Inspections are required)

Spokane County, Washington• Basics

– 500,000 people– 7 FTEs– Collect $6M in fees, average $1.5M in capital per year

• Largely Dry Wells– Required to register all dry wells by 2012– Required to identify any potential problem locations by

2012– Approved list of BMPs for Dry Wells (mostly filtration)

• Utility established in 1992– $21/yr for average residence– Charge commercial at the same rate per sf as residential

Spokane County, Washington• Newly Established Three Priority Areas with

higher rates– $45-65 per year in priority areas– High flooding– Dense Development– Water Quality challenges– Identified in Master Plan

Montana Timeline

• First annual reports were turned in January 28, 2008

• Plan implemented by the end of 2010

Cities should participate in the TMDL process to advocate for Stormwater as well as Wastewater

There should be a link between chosen BMPs and impairment

Decision process should match impairment listings

Pollutant Source/ Activity

Physical Parameters

Synthetic Organics

Petroleum Hydrocarbons

Heavy Metals Nutrients Pathogens Sediments

Vehicle Service Facilities x x x

Gas Stations x x x Metal Fabrication Shops x x x

Restaurants Auto Wrecking Yards x x x x

Mobile Cleaners x

Parking Lots x x x Residential Dwellings x x x x x x

Parks/Open Spaces x x x

Construction Sites x x

City Shops x x x x Streets and Highways x x x

Marinas

Golf Courses x x x

Sewer Overflows x x

When permits are renewed, numeric load targets may be added.

Many parties contribute to stormwater in the Helena area

Timeline

Montana cities may face water quality BMPs in the future

Standards were set at MEDIAN numbers

Initial sampling results

(mg/L) Standard City data

TSS 125 464

COD 80 162

Total P 0.41 0.64

Total N 2.0 3.8

Copper 0.04 0.036

Lead 0.165 0.026

Zinc 0.210 0.377Initial sampling results from two cities were over median values

Tips for Sampling Permitting

• Choose sites where you could implement at BMP if you needed to

• Choose where downstream treatment (even subsurface) is already taking place

• Sample the receiving water body at the same time that you sample your discharge

Case Studies from other MS4 with Finalized TMDLs• Virtually all

called for percentage load reductions and construction-related BMPs mandated through the MS4 permit Many case studies used the

Phase 2 program to ensure compliance

Is a Master Plan Required?

• The permittee shall provide a rationale for why each of the BMPs and measurable goals was selected.

• Documentation of your decision process is required.

In some areas, decision process documentation language includes significant requirements.

What should you do?

• Budget now for future costs of the program

• Form a utility now if you haven’t already

• Sample, sample, sample-more data is better

• Document your decision process for choosing permit activities, link choices to impairment listing

Areas for Potential Collaboration in Stormwater Management

1. Engineering Standards and BMPs

2. Operation and Maintenance Standards

3. Phase 2 NPDES Annual Reporting

1. Engineering Standards

Outline of Engineering Standards from Helena

A. Hydrologic Analysis

B. Hydraulic Analysis & Design

C. Water Quality Best Management Practices

D. Materials

E. Methods of Construction & Best Management Practices

F. Sediment and Erosion Control

G. References

Best Management Practices

• Issues– Lots of BMP Manuals/Catalogs Available from Other Sources, But

What’s Applicable for Montana Cities?– What Constitutes Pollutant Removal to the “Maximum Extent

Practicable” (MEP)?

• Montana Specific Considerations– Appropriate Sizing for Montana Hydrology– Design and Construction for Effective Performance

• Target Montana Water Quality Pollutants of Concern

– Reasonable Maintenance

• Potential Benefit to Montana Cities– Avoid Duplicate Efforts– Leverage Development of Core BMPs for Common Needs– Streamline Review for City Staff

Stormwater BMPs for Upper Great Plains/Rocky Mountain Climate

• Appropriate Plant Selection– Re-vegetation During Short

Growing Season

• Cold Weather Considerations– Freeze/Thaw

– Rain-on-Snow

• Modifications for Implementation– Baffling of Detention Ponds

– Heat Tracing?

Example Stormwater BMPs

• Helena Stormwater BMPs include:– Water Quality (Runoff Treatment)

• Source Control (Good Housekeeping)

• Categorized Structures– Conventional Pollutant

– Oil/Water Separation

– Nutrient Treatment

– Runoff Control (Runoff Quantity Control)• Detention Facilities

• Infiltration Systems

Example Stormwater BMPs

Section – Combined Runoff Treatment/Detention Vault

Example Stormwater BMPs

Section – Spill Control Oil/Water Separator

Advanced and Emerging Treatment and Control Technologies for Stormwater

• Hydrodynamic Separators– Stormceptor

– BaySaver

– VortechsTM

– Downstream DefenderTM

– CDSTM

– V2B1TM

• In-Line Filtration Systems– Stormwater Management Inc. (StormFilter)

– Aquashield, Inc. (Swirl Concentrator and Filter)– Zeta Technology (Arkel Filter)

• In-Drain Filtration Systems– Stormwater Management Inc. (Catch Basin StormFilter)

– AbTech Industries (UltraUrban Filter)– UltraTech International (Catch Basin Insert)– Hydro Compliance Management, Inc (Hydo-Kleen Filtration)– DrainWorks, Inc (DrainPac)– Kristar Enterprises, Inc (Flo-Guard Plus)

Hydrology Modeling

• Issues– Is The Existing Basis for Facilities Sizing Appropriate?– What Constitutes Pollutant Removal to the “Maximum Extent

Practicable” (MEP)?• Montana Specific Considerations

– Appropriate Sizing for Montana Hydrology– Design and Construction for Effective Performance

• Target Montana Water Quality Pollutants of Concern– Reasonable Maintenance

• Potential Benefit to Montana Cities– Consistent Basis for Sizing Stormwater Facilities– Regulatory Agency Concurrence– Avoid Duplicate Efforts– Leverage Development of Engineering Approach to Sizing– Streamline Review for City Staff

Hydrology Models for Single Event Sizing (and Continuous Simulations)

• Several modeling applications are in Helena Engineering Standards– Stormshed– StormCAD– SWMM– TR-20– HSPF

• Rational Method (Q=CIA) allowed only for sizing conveyance facilities

Off-the-Shelf Software Application (StormShed) - Usability

• Simple stick figure construction of stormwater system

• Relatively inexpensive for Cities and Engineers to acquire (Example StormShed: $2,400 for the first license and $1,200 for each additional license)

2. Operation and Maintenance Standards

Operation and Maintenance Standards

• Issues– Are City’s Existing Maintenance Practices Adequate?

– Are There Common Practices That Could Be Standardized?

• Montana Specific Considerations– Much of New Stormwater Infrastructure is Constructed

by Developers• Who Will Ultimately Maintain These Facilities?

• Potential Benefit to Montana Cities– Reliable Plan for Expanding Infrastructure

– Phase 2 NPDES Permit Compliance

Standardize O&M Practices• Goals for frequency of

maintenance activities? • Goals for condition

assessment?• Standard O&M

agreements?• Many Phase 1s have

gone to annual inspection

• Developer Bonds for O&M?

Stormwater Maintenance and Operational Practices

3. Phase 2 NPDES Annual Reporting

Phase 2 NPDES Annual Reporting

• Issues– New Administrative Tracking and Reporting Burden for

Cities

• Montana Specific Considerations– Satisfying MDEQ’s Phase 2 Stormwater NPDES Permit

For An Acceptable Annual Report

• Potential Benefit to Montana Cities– Standardize Annual Permit Report Format and Content

– Concurrence from MDEQ on Acceptability

– Streamline Review for City Staff

Standard Annual Reports

Cover page from DB from AmandaCover page of Helena’s permit application

Questions?

Overview of EPAPhase II NPDES Permit

• Six Content Areas– Public Education/Involvement– Iliicit Connection– Pre and Post Construction– Good Housekeeping

• Submit Permit Applications-March, 2003– Apply for Coverage Under General

Permit (in MT not available until November 2004)

– Description of Storm Water Management Program

• Fully Implement “Storm Water Management Program within 5 Years