Section 10-A1308. IN-2.3 COMBINED SEWER SYSTEM (CSS)

 

1308.1As noted earlier, a portion of the District’s sewer system includes combined wastewater and stormwater pipes. This area encompasses about 12,600 acres-or one-third of the District’s land area (see Figure 13.3). A majority of this area was developed before 1900. 1308.1

 

1308.2In 2002, WASA developed a Long-Term Control Plan (LTCP) to eliminate Combined Sewer Outfalls and thereby improve water quality (see text box on next page). A key component of the plan is the construction of four large tunnels which will allow runoff to be stored and then transported to the Blue Plains Wastewater Plant for treatment and gradual release. Two of the tunnels will be located near the Anacostia River, one will be near the Potomac River, and one will be near Rock Creek. The LTCP also includes separation of combined sewers in several sections of the District, consolidation and elimination of 13 of the 60 outfalls, and implementation of Low Impact Development (LID) practices at WASA facilities and across the District. The project will take 20 years to complete and has a projected construction cost of over $1.2 billion. 1308.2

 

1308.3When fully implemented, combined sewer overflows will be reduced by a projected 96 percent (98 percent on the Anacostia River), resulting in improved water quality and less debris in local waterways. Overflow events would be reduced to two per year in the Anacostia River, four per year on the Potomac and Rock Creek, and one per year at Piney Branch. 1308.3

 

1308.4The LTCP provides for an effective balancing of cost, benefits and environmental protection that will greatly reduce CSO discharges. However, even with the full implementation of the LTCP, CSO discharges will still occasionally occur. Additional provisions to improve water quality will also be needed. 1308.4

 

See the Environmental Protection Element for additional information on sewer overflow conditions as well as the need to update the District’s water quality standards.

 

1308.5Figure 13.3: Combined Sewer System Area

 

http://www.planning.dc.gov/planning/frames.asp?doc=/planning/lib/planning/2006_revised_comp_plan/13_infrastructure.pdf

 

1308.6Figure 13.3: Policy IN-2.3.1: Reducing CSO Outfalls

 

Reduce the Combined Sewer Overflow (CSO) outfall to the region’s rivers by implementing WASA’s Long Term Control Plan (LTCP). 1308.6

 

1308.7Action IN-2.3.A: Rehabilitate Pumps

 

Rehabilitate and maintain pump stations to support the LTCP and off-load stormwater in targeted combined sewer areas. 1308.7

 

1308.8Action IN-2.3.B: Federal Funding

 

Pursue federal funding to cover an equitable share of the LTCP. Also, pursue funding from Maryland and Virginia and consider a graduated rate structure for DC residents as a water conservation initiative. 1308.8

 

1308.9The Long Term Control Plan

 

The Combined Sewer System Long Term Control Plan (CSS LTC P) (July 2002) provides the District’s approach to reducing sewer overflows. Upon completion of the CSS LTC P improvements, existing overflows should be reduced by approximately 96 percent. The CSS LTC P that was originally scheduled to be implemented over the next 40 years is now being implemented over 20 years. WASA utilized financial planning models developed by the EPA to assess the long-term impacts of these improvements on customer rates.

 

Key components of the LTC P include:

 

•Construction of storage tunnels, allowing storage and gradual release of CS O flows

 

•Separation of the combined sewers in several sections

 

•Consolidation and elimination of 13 outfalls

 

•Pumping station improvements

 

•Low Impact Development.

 

The complete LTC P including the detailed list of control program elements can be found at http://www.dcwasa.com/education/css/ longtermcontrolplan.cfm.

 

notation

The provisions of Title 10, Part A of the DCMR accessible through this web interface are codification of the District Elements of the Comprehensive Plan for the National Capital. As such, they do not represent the organic provisions adopted by the Council of the District of Columbia. The official version of the District Elements only appears as a hard copy volume of Title 10, Part A published pursuant to section 9a of the District of Columbia Comprehensive Plan Act of 1994, effective April 10, 1984 (D.C. Law 5-76; D.C. Official Code § 1 -301.66)) . In the event of any inconsistency between the provisions accessible through this site and the provisions contained in the published version of Title 10, Part A, the provisions contained in the published version govern. A copy of the published District Elements is available www.planning.dc.gov.