A Primer on Stormwater Management, your Facility and the Chesapeake Bay. Tom Schueler Chesapeake Stormwater Network June

A Primer on Stormwater Management, your Facility and the Chesapeake Bay Tom Schueler Chesapeake Stormwater Network June 5. 2017

Key Themes Why do we need to be concerned about Stormwater? What are all these letters about? (MS4, TMDL, BMP etc) What are stormwater practices and what do they actually do? What is the Full-Cycle approach to managing stormwater practices? What can I do at my facility to prevent stormwater pollution?

Urban Stormwater Basics Center for Watershed Protection, 2001

10% IC

30% IC

60% IC

Impervious Cover

Runoff Coefficient (Rv) Relationship Between Watershed Imperviousness (I) and the Storm Runoff Coefficient (Rv) (Source: Schueler, 1987) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 10 20 30 40 50 60 70 80 90 100 Watershed Imperviousness (%)

IC and Stream Habitat 8-10% < 5% 20% > 65% 30%

What are all these letters about? Bay TMDL MS4 Permit Federal Facilities

The Chesapeake Bay Watershed, by the numbers 64,000 square miles in area Forest is about 58% of the area Row Crops are about 10% About 10% is turf and 5% is paved The rest is pasture, meadow, wetlands and open land About 3.2 million animal units (chicken/hogs) and 40 million tons of manure ~ 500 wastewater plants that discharge 3 billion gallons per day 19

Chesapeake Bay Total Maximum Daily Load (TMDL) The Bay Pollution Diet Chesapeake Bay TMDL was finalized by EPA and Chesapeake Bay partners in 2010 Bay Pollution Diet set goals to install all practices needed to clean up the Bay by 2025, with 60% of the practices in place by end of 2017 Final reduction targets for nutrients and sediments by 2025 or beyond Federal facilities lead by example under the Executive Order 20

Key Sectors Involved in the Bay Pollution Diet Agriculture: Farms and Feedlots Wastewater Treatment Forest (60% of CBW) Air Deposition Urban and Suburban Runoff 21

Chesapeake Bay TMDL: Pollution Diet for All Sectors and Sources 400 350 300 250 200 150 100 50 0 Nitrogen 1985 2009 2015 Simulated Pollution Loads Delivered to the Bay (million pounds/year) 25 20 15 10 5 0 Phosphorus 1985 2009 2015 11,000 10,000 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 2017 Interim target 2025 Planning Target (amt. allowed in Bay) Sediment 1985 2009 2015 22

Indicators of improving ecosystem health: We are making progress Blue Crabs Bay Grasses Water Clarity WQ Standards Attainment Reducing Pollution 23

MS4 PERMITS A municipal separate storm sewer system (MS4) is a conveyance or system of conveyances owned by a state, city, town, or public entity that discharges to waters of the U.S. and is designed or used for collecting or conveying stormwater but is not a combined sewer Federal facilities may require MS4 permits

Municipal Stormwater Permits Required Minimum Management Measures 1. Public Education and Outreach * 2. Public Involvement and Participation 3. Illicit Discharge Detection and Elimination * 4. Construction Site Runoff Control * 5. Post Construction Stormwater Management * 6. Municipal Pollution Prevention and Good Housekeeping * Annual compliance reporting 25

The Link Between Ms4 Permits and the Bay TMDL: Nutrient Accounting Numerical load reduction or impervious cover treatment requirements are now included in many new Ms4 permits Existing MS4 permit requirements for BMP maintenance, inspection and reporting are used to comply with Bay BMP verification Most of the MS4 minimum management measures are eligible for pollutant reduction credit 26

Federal MS4 Permit Requirements Measurable and enforceable measures Budget for stormwater controls, including permit requirement Reduce turf grass fertilizers Consistent with Chesapeake and local TMDLs Include estimated dates for meeting them Clear tracking, reporting and verification requirements 27

MDE Restoration Targets for Federal Facilities MDE estimates nutrient targets for federal facilities that are equivalent to a 20% retrofit of any untreated impervious area at a facility. The target only applies to the urban stormwater loads from federal facilities. Don t worry about agriculture or forests on federal lands

What are stormwater practices and how do they actually work? The goal of stormwater practices is to design the post-development landscape so that it functions as if the hard surfaces were actually forest or meadow cover thereby reducing flooding, bank erosion and pollutant loads to predevelopment levels

Bioretention: How it Works Runoff flows into a bioretention facility and temporarily ponds. Water then slowly filters through the filter bed and either is collected by the underdrain and sent to the storm sewer system or infiltrates into the surrounding area. 30

Key Parts of Bioretention Ponding area Filter media Pea gravel Overflow Vegetation Optional: Underdrain + stone Infiltration sump 31

Infiltration

How It Works Infiltration 33

How It Works Surface Sand Filter

Permeable Pavement

How It Works Permeable Pavement Photo credit: http://wincostormwater.com/page/4/permeable-pavement

Grass Channels

How It Works Grass Channels 38

Wet Stormwater Pond

Dry Stormwater Pond

Non-structural Stormwater Practices Street Sweeping Storm Drain Cleanouts BMP Maintenance Municipal Housekeeping Pollution Prevention Plans Control of Illicit Discharges

What is the Full-Cycle management approach?

Full Cycle Management 1.Monitoring 7. Makeover 2.Assessment 6.Maintenance 3.BMP Design 5.Inspection 4.Construction

What is the Full Cycle Approach? 1. Establish minimum performance objectives for the practice 2. Ensure the practice is feasible for the site 3. Meet design criteria to maintain performance over entire cycle 4. Be properly constructed and established 5. Regularly inspect using visual indicators 6. Use landscape contractors to maintain BMP function over time 7. Perform a make-over when functions diminish

What can I do at my facility to prevent stormwater pollution? Be the eyes and ears at your facility Coach your co-workers on pollution prevention practices Look for illicit discharges in your storm drain system Make your landscaping greener Know when and how to maintain your stormwater BMPs

6 Common Hotspot Operations Vehicle Operations Outdoor Material Waste Management Physical Plant Turf / Landscaping Areas Unique Operations

Coach Your Co-workers Involve employees to increase their stormwater pollution prevention IQ Use the CSN Stormwater Benchmarking Tool to assess your site:

Prevent Parking Lot Pollution Evaluate the condition, drainage and maintenance of the parking lot to reduce runoff and reduce pollutants

Prevent Spills at Fueling Areas Inspect Fueling Areas at the Site Cover Fueling Islands Dry Spill Response Kits Redesign Flows to Prevent Storm Drain Entry

Seasonal Operations/Outdoor Wash-water Assess seasonal operations at the facility with the potential to produce polluted runoff or wash-water out of the storm drain system

Spill Control and Response Walk the site to find areas of greatest spill risk, and critically evaluate how to improve spill response Provide spill kits at high risk areas of site Update emergency contact numbers Create an unannounced fake spill

Prevent Runoff From Outdoor Storage Walk the site to look for materials stored outside on a temporary or permanent basis that could come into contact with rainfall Place materials on pallets Temporary cover Secondary containment and berms No streak or stain lines on way to storm drain

Exterior Dumpster Management Walk the site to look for dumpster juice and spillage Dumpster covered, have lids and are water tight Schedule pickups with solid waste contractors frequently Disconnect dumpsters from storm drain