Mountain Lake has been officially designated a "toxic cleanup site" by the Federal Government --mainly due to unacceptably large concentrations of lead and other materials in the lake's sediment.
Supervisor Alioto-Pier has scheduled Mountain Lake on the agenda for the Board's Land Use Committee on Monday February 25th at 1 p.m. at City Hall. Please attend if you can.
Here is Supervisor Alioto-Piers' excellent summary of the situation:
Please be advised that the hearing on the status of Mountain Lake is scheduled for Monday, February 25, 2008 at 1:00 p.m. in the Land Use & Economic Development Committee. The hearing will be held in Room 263 at City Hall. As many of you know, Mountain Lake is one of the last two remaining natural lakes in San Francisco. It is a spring-fed natural lake covering almost four (4) acres located mostly in the southern portion of the Presidio. The City and County of San Francisco ownd the adjacent hiking trails and small beach in front of the lake. The lake is directly east of State Highway 1 just before the MacArthur Tunnel leading to the Golden Gate Bridge.
Over the years, the lake has shrunk in size and depth and is in danger of eventually becoming a meadow if it is not dredged. Mountain Lake has been impacted by stormwater roadway runoff from Highway 1. Since their inception in the 1930’s, a series of storm drains collecting runoff from Highway 1 discharge directly into the lake through piping underneath and adjacent to the roadway. The lake sediments have been compromised by heavy metals, sediment and petroleum hydrocarbons that have been washed off the roads and into the lake. In fact, Mountain Lake is now officially a designated toxic clean-up site.
The lake water and sediment quality is also compromised by other factors, such as filling of the lake during the construction of the MacArthur Tunnel and Highway 1. There are two needed actions to improve the lake water and sediment quality. Those include (1) diverting the storm drains flowing directly into the lake from the roadway and replacing the outlet and overflow pipes and (2) dredging the lake to remove contaminated sediments and fill.
For a number of years, the Presidio Trust, the United States Army and CalTrans have gone back and forth on who is responsible for remediating Mountain Lake.
The hearing will explore the extent of the problem, including any hazards to Mountain Lake users. The hearing will also focus on potential solutions and timelines for completion.