San Francisco Sewer System Master Plan (SSMP) San Francisco Public Utilities Commission

The goals of the SSMP are to develop a long-term vision and strategy for the management of the City’s wastewater and storm water, address specific challenges facing the system, and maximize system reliability and flexibility.  HCE has been engaged in this project to determine and evaluate needs by developing and calibrating the collection hydraulic/hydrologic system model, and provide modeling support for alternatives to Bayside discharges.

Water Supply Improvement Program (WSIP) Environmental Impact Report (PEIR) San Francisco Public Utilities Commission (SFPUC) 

 The Program EIR addresses the potential environmental effects of improving and expanding the regional water supply system to meet the proposed system service goals for water quality, water delivery and reliability through the year 2030.  HCE provided hydrology and hydrogeology support for the surface water and groundwater resources sections of the WSIP PEIR.  Tasks included analyzing model results for various water supply scenarios and supply alternatives in order to determine potential impacts to surface water and groundwater resources. 

Sunnydale Sewer Improvements

San Francisco Department of Public Works, Bureau of Engineering

HCE performed the hydraulic analysis for the proposed $20 million flood control project in the Sunnydale area district of San Francisco by developing hydraulic design concepts using the XP SWMM computer model. HCE also used physical hydraulic modeling to develop design parameters of pertinent complex junction and diversion structures.

 Combined Sewer Discharge Monitoring Improvements

San Francisco Department of Public Works

Working in concert with City staff from multiple bureaus and departments, HCE has embarked on a study which will add additional sewer collection system and weather monitoring devices and gauges, integrate these into the Data Collection System (DCS), provide some DCS programming improvements to facilitate display of this information to treatment plant operators and others, quantify discharge volumes at critical CSD reporting locations, and provide initial Infoworks modeling support to test possible use of the new monitors in advanced operational decision making.  In addition, we will develop recommendations for optimizing the operational control at Channel to minimize CSD frequency and improve water quality of CSD by enhancing existing meters and rain gauges, improving operator access to meter information in real time and providing improved gate control set point logic via DCS control logic programming upgrades.  A third task will be to improve existing Sunnydale/Griffith PS operating guidelines by improving the calibration and reporting of existing meters, and provide preliminary new pump operating guidelines based on enhanced meters and rain gauges.

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 Pollutant Mass Balance Study 

San Francisco Public Utilities Commission

The San Francisco PUC is regulated by the Combined Sewer Overflow Control Policy through their National Pollutant Discharge Elimination System Permits.  A requirement of the CSO Control Policy is to determine the efficacy of the combined sewer control structures. Additionally, San Francisco Bay has been designated an impaired water body and under the Clean Water Act, Total Maximum Daily Loads (TMDLs) are required to reduce pollutant loading.  Implemented during the 2006 – 2007 wet weather season, the Pollutant Mass Balance Study is an on-going program that utilizes flow monitoring, data collection system data and rainfall data to measure the frequency, volume and flow rate of combined sewer discharge events.  Water quality data is then compared against these events to determine the rate and system efficacy of mass removal. Data from the program is used to create a model of combined sewer flow and disposal in San Francisco.  The model and resultant information provides a basis for further improvements in the wastewater management system, with the ultimate goal of reducing the levels of key pollutants discharged to the Ocean and Bay.  An associated goal is to make the model and system performance data available to WWE and DPW staff for use in related modeling efforts.