Combined Sewer System Long Term Control Plan - DC Water

Responses to Comments
of the complaints were general in nature and not specific to one area. Commenters
indicated that while the Draft LTCP would address flooding in some areas, it would not
address problems District-wide. Other commenters indicated that the LTCP should
indicate whether the proposed improvements will prevent reoccurrence of the flooding
that occurred on August 11, 2001. A commenter indicated that WASA was not
responsive to the flooding of August 11, 2001. Specific complaints were issued about the
following areas: (128, 129, 131-139, 141, 142, 143,145, 148)
31 st and K Street NW in Georgetown
West Virginia and Mt Olivet, NE
Basement apartments in Dupont Circle area
Bloomingdale and Trinidad neighborhoods
The purpose of the LTCP is to select CSO controls for the combined sewer system.
Addressing the need for capacity/flooding relief is being addressed as part of a separate
City-wide evaluation of the sewer system. However, while preparing the LTCP, an
opportunity was identified to address long standing flooding problems in the Northeast
Boundary drainage area. This includes the areas of West Virginia and Mt. Olivet, NE,
the Bloomingdale and Trinidad neighborhoods, and Rhode Island and 4 th Avenues NE.
These areas were addressed due to the historical and well known nature of the chronic
flooding occurring in these areas. Many of the areas that flooding on August 11,
2001were not previously known as susceptible top flooding. These areas will be
addressed as part of the city-wide assessment of the sewer system.
9.2 EPA commented that the LTCP should describe in greater detail how and on what
schedule the recommended plan will alleviate flooding in the Northeast Boundary area
(130). EPA also commented on the new “relief outfall” into the Anacostia near the
Northeast Boundary Swirl Facility and outfall 019 with the following questions: 1) What
is the predicted frequency and duration of overflows for this outfall 2) Is it included in
Table 9-3 3) Are the flows part of the receiving stream model for the Anacostia 4)
What are the impacts to water quality from the discharge 5) What controls will be
placed on the new outfall 6) How is the new outfall to be permitted (150)
Flooding in the Northeast Boundary is described on pages 8-26 and 8-27 of the LTCP.
Three of the tunnels in the Draft LTCP address flooding in these areas as follows:
Tunnel parallel to the Northeast Boundary Sewer
Short tunnel from the Northeast Boundary Sewer to Rhode Island & 4 th St NE
Short tunnel from the Northeast Boundary Sewer to West Virginia & Mt. Olivet,
NE
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