Location: Candlestick Point, San Francisco, CA
Time Frame: 2011

Increase the existing tidally influenced wetland area from 9 acres to over 20 acres; create 2 isolated bird nesting islands; provide nursery areas for fish; provide interpretative trails; and construct a new interpretive center. The restoration addressed soil contamination issues arising from previous fill activities. Construction of the wetland generated about 265,800 cubic yards (cy) of cut soils that were managed according to applicable regulations.


Scope of Services

NOA provided Quality Control during construction for the purpose of verifying the project met approved plans and specifications. NOA services included inspection of all cut/fill materials on the order of 15 feet for lower and upper wetland cover, wetland topsoil, and upland fill and cover. Samples of the screened material were tested in NOA laboratory to determine maximum dry density and optimum moisture content. NOA was responsible for performing field compaction testing to verify that soils met critical minimum and maximum relative density requirements for the wetland areas and that fill materials met project specifications. Laboratory testing of all samples for analysis were performed in NOA certified laboratories.

Challenges

The project schedule had strict time constraints that needed to be met by the contractor. This in-turn required NOA to provide detailed daily reporting of inspections and laboratory testing. As soil conditions changed or new material was encountered, laboratory testing of the material was required before the project could proceed. Where project specifications were vague regarding grading work NOA was able to utilize our geotechnical background and experience to effectively communicate and work with the project geotechnical engineer, environmental engineer, owner, and contractor to reach acceptable solutions for all parties involved. Due to the contaminated working conditions, all NOA employees working on-site were required to obtain Hazwoper certification.