United States
Environmental Protection
Agency

National Priorities List (NPL)

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*NPL Site

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CAPITOL LAKES

Baton Rouge, Louisiana

East Baton Rouge Parish

(?) Site Location:

OLEM/OSRTI
Washington, DC 20460

September 2023

The Capitol Lakes site in Baton Rouge, Louisiana, is currently composed of three lakes: North Lake, South Lake, and
East Lake, and occupies an aerial extent of approximately 60 acres adjacent to the State Capitol Building and the
Governor's Mansion in downtown Baton Rouge. The Capitol Lakes sub-watershed is an urbanized, mixed-use area
comprised of residential, commercial/industrial, and governmental properties.

uSite History:	

The Capitol Lakes were originally part of a natural drainage system called Grassie Bayou. Grassie Bayou was contiguous
with the Mississippi River until the early 20th century, when it was dammed creating the lake system. Because there is
no natural outlet, water which flows into the lake must be pumped out by a pumping station on the Mississippi River.
This creates a stagnant lake system and causes retention of sediment and contaminants. Contamination of the lake system
was first found in 1972 with the detection of oil contaminated with pesticides and Poly chlorinated Biphenyls (PCBs). In
1983, when the Louisiana Department of Environmental Quality (LDEQ) investigated a report of PCB-laden oil entering
the lake, a fish advisory was established due to PCBs and various metals which remains in place today.

1 Site Contamination/Contaminants:	

Antimony, arsenic, cadmium, copper, lead, manganese, zinc, mercury, and PCBs in the form of Aroclor-1016 and
Aroclor-1260 in sediment at significant concentrations provides evidence that hazardous substances have migrated to
North Lake and South Lake.

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