February 4, 2004

Addendum to Preliminary Water Quality Screening Plan

2003/04 Wet Season

January 26, 2004

Lake Merced Restoration – Phase 2 Pilot Stormwater Enhancement Project

Prepared by the North San Mateo County Sanitation District

and the San Francisco Public Utilities Commission

with assistance from EOA, Inc.

  1. Page 2. Paragraph 5. As stated, “The actual number of sampling episodes may vary, depending on factors such as weather patterns and the availability of staff and equipment.”  Include a new clarifying last sentence as follows: “However, in all cases at least one set of lake samples will be collected from each storm.”

  1.  Page 2. Paragraph 6. As stated, “Water quality samples will be collected from the lake as soon as possible after the diversion is closed and/or the end of the storm event but no longer than 48 hours after the diversion is closed.”  Include a new 3rd sentence as follows: “If the results for open water samples LM-4,5,or 6 exceed the maximum levels listed on Table 1, then additional sampling rounds will be conducted until the levels have dropped below the maximum levels.”

  1. Figure 1. Add a new sampling station in the wetlands area (LM-Wetlands) where a daily bacteriological sample will be collected for four consecutive days following each of the pilot discharge events.

  1. Attachment 1, Public Notice. Revise paragraph 2 to read as follows:   This demonstration involves using a vegetated area along a small section of the southwestern shoreline of South Lake Merced  as a stormwater treatment wetland.