© 2010 Malcolm Pirnie, Inc. All Rights Reserved National Implications of the Federal Pollution Limits for the Chesapeake Bay Clean-Up Clifton Bell, P.E., P.G. Malcolm Pirnie, Inc

Challenges for Localities: Address Existing Nutrient Sources UrbanStormwater Wastewater  WWTP Upgrades  Failing septic systems  Stormwater retrofits  Fertilizer controls

NewDevelopment & Redevelopment Wastewater Challenges for Localities: Staying Under the Nutrient Cap  Strict stormwater controls  Advanced septic systems  Reuse / recycle  Trading/offsets?  Septic sprawl?

Urban Runoff: Minority of the Problem, But a Majority of Projected Cost 70% of TMDLcosts?

Urban Retrofits the Most Expensive Way to Reduce Nutrient Loads AgriculturalPractices WWTPUpgrades UrbanStormwaterRetrofits $5 - $150 per lb phos. $15 - $200 per lb phos. $3,000 - $20,000 per lb phos.

Stormwater Retrofit Costs  Pond retrofits : $15-30k / impervious acre  Advanced retrofits: $75-300k / impervious acre What regulators have asked: 20% 5 years Retrofit up to 20% of impervious surface in a single MS4 permit term ( 5 years ).

Some Recommendations  Negotiate reasonable MS4 permits Avoid extensive urban retrofits Emphasize redevelopment- driven improvements Non-structural practices  Cross-sector planning  Explore opportunities for wastewater recycle & reuse Storm- water Agri- culture Waste- water