WSP USA ENVIROMENT & INFRASTRUCTURE INC.

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Scope of Services and Schedule Typically, street improvement plans and grading plans are only needed when a property appears to have a private inlet and we need to assess if the storm drain connects directly to the City's storm drain system or to the back of a catch basin. Since WSP has completed the refinement for each catch basin in the City, additional refinement will be needed for redevelopment projects or when additional catch basin or private drop inlets are observed in the field. Under this scope of work, our staff can continue to refine drainage areas based on additional information received or observations. On -Land Visual Trash Assessments (OVTAs) WSP understands the City's goal of meeting the Track 1 compliance. Because of issues such as direct connections and some catch basins identified as infeasible to install FCS, the City has installed CPS in catch basins that were feasible, including both PLU and ALU areas, to meet this Track 1 compliance strategy. The Bay Area Storm Water Management Agencies Association (BASMAA) developed a trash model that correlates different land uses with TGRs for both • A = clean, no trash (Low trash generation rate) • B -few pieces of trash (Moderate trash generation rate) • C = small to moderate amounts of trash (High trash generation rate) • D - moderate to high amounts of trash (Very High trash generation rate) PLUS and non-PLU areas and further connects these TGRs with an OVTA score that can be verified through field monitoring. This model will ultimately be used for land substitution under the Track 1 compliance strategy. WSP completed two rounds of OVTA surveys to verify baseline TGRs. Initial OVTA survey results suggest that City land use TGRs are considerably different than BASMAA modeled TGRs. WSP recommends additional rounds of OVTAs under the next contract to further strengthen findings and adjustment of modeled TGRs based on the initial OVTAs. WSP also anticipates the TGR model will need to be verified r .h G.n.munn am Ia.n.mt.cr*..d y f. �J ,........�. 30 is XQ r L� f. 4? .� « �t•�r. .IL. '; periodically, requiring additional OVTAs completed. While our initial round of OVTAs were completed using standard two -person field team survey methods, WSP has developed new methods to complete cost-effective trash surveys. WSP's team uses a camera and develops a machine learning algorithm to successfully identify trash and develop corresponding visual trash assessments scores for several survey segments. We anticipate using the machine learning technology for future OVTAs proposed under this contract. Trash Generation Rate Calculations - As described above, WSP prepared the initial TGR maps to support the land substitution compliance maps for the City and adjusted the TGRs based on strategy and trash load calculations. the OVTA findings. WSP assumes TGR maps will be updated based on additional OVTA findings to further strengthen findings and periodic verification will be needed based on the new MS4 permit requirements. After the adjustments are made, WSP will be prepare the TGR calculations. Our extensive I City of Santa Ana I Industrial/Commercial Inspection and NPDES Program Support Services I page 26 RFP No. 23-028