The City of Washington D.C.’s plunge into green infrastructure was featured in a number of sessions at the Low Impact Development Conference in Portland, Maine. The city, through D.C. Water, is operating under an amended consent decree with EPA to reduce CSO discharges.
D.C. Water is responsible for water delivery, waste water and stormwater collection and removal. The City of Washington D.C. operates D.C. Water separately from the D.C. government. D.C. Water doesn’t own or manage the land used to distribute drinking water or handle stormwater. As a result, the utility works closely with other city agencies like D.C. Transportation. Like many cities, D.C. Water determined that focusing stormwater green infrastructure in ROW was the best way to remove the highest volume out of the stormwater system at the lowest cost.
“We have to be competitive with gray infrastructure, otherwise it will not last,” said Bethany Bezak, Green Infrastructure Manager, D.C. Water.
D.C.’s EPA amended consent decree requires reporting and updates. Based on results, Bethany explained, “either we will continue with green infrastructure or go back to gray.” D.C. Water must prove to the EPA and the Justice Department that green stormwater infrastructure will be as effective as installing large underground tunnels. Currently, two GSI projects are underway in CSO areas. One, in the Potomac River watershed and another in the Rock Creek watershed.
Green infrastructure plans call for managing 133 impervious acres in the Potomac watershed and 365 impervious acres in the Rock Creek watershed. First projects are underway for 44 acres in the Potomac and 20 acres in the Rock Creek.
The initial projects are designed to demonstrate that green infrastructure can capture runoff, can be retrofitted in urban areas, adds amenities to the sites where it’s employed and is a cost-effective solution.
D.C.’s $2.6 billion program is entirely rate payer funded. For success, focus must be on long-term performance, Bethany emphasized. Implementation of projects is staggered to incorporate learning and adaptation along the way.
Stakeholder engagement is key. “In D.C. you can do everything correctly technically and fail at outreach and it will cause the project to fail,” she said. D.C.’s community outreach drivers include communication about temporary construction impacts on the neighborhood, how stormwater features will impact neighborhood character and to assure residents that the city will maintain the features. D.C. Water will provide maintenance for the life of the facilities.
“We also hear, ‘What can I do?’ A lot of people want to be part of the solution,” said Bethany. One of the easiest ways the city promotes for residents that want to help out is downspout disconnection to keep rainwater on the residents’ private property.
“We’ve got about 2,300 properties in pilot areas with the potential to disconnect downspouts,” she explained. Next spring, D.C. Water will launch a voluntary downspout disconnection program. Eligible participants may also receive a free rain barrel.
On the cost side, she pointed out that D.C. Water expected bioretention facilities to be more cost effective than permeable pavement, but so far, their most cost-effective green stormwater infrastructure has been installing green alleys.
D.C. Water is also working with Water Environment Federation on the National Green Infrastructure Certification Program to train workers for long-term performance success of the installed features. The Certification is meant to help create long-term green infrastructure jobs that pay a living wage. The program is being built with ANSI/ISO/IEC accreditation guidelines. First certifications will be awarded in January 2017. The certification will require ongoing education to be maintained. While D.C. Water and Water Environment Federation are the founders of the certification, a growing national coalition of municipal and utility partners has joined in.
While D.C. is pushing into green infrastructure, there are contingency plans. “We are all in, but we need to be competitive with gray,” Bethany emphasized. At this point, garnering additional support for green stormwater infrastructure because of the co-benefits it provides in additional ecosystems services is not an option.
“Soft/co-benefits are not well quantified,” she explained. D.C. Water has built green stormwater infrastructure facility monitoring and performance into their program. The initial Potomac and Rock Creek projects will be documented and presented to EPA. If green infrastructure is deemed practicable, D.C. Water has a green infrastructure rollout for multiple projects over the next decade.
And if green infrastructure isn’t practicable? There’s alternate plans for a Potomac Tunnel capable of handling 40 million gallons and a Rock Creek storage facility that can handle 9.5 million gallons. Oh yeah, and ratepayers will see a larger spike in their water bills as a result.
Long Term Control Modification for Green Infrastructure prepared by District of Columbia Water and Sewer Authority.
NewTerrain September 15, 2016.