Wastewater Treatment Permitting Assistance and Reclamation/Reuse Alternatives Study
City of Lodi, California

West Yost has been providing wastewater treatment and disposal system planning and regulatory compliance services for the City’s White Slough Water Pollution Control Facility (WPCF) since the late 1990s. This work has included several planning and regulatory studies related to the current and future requirements for surface water discharge, biosolids land application, and recycled water use on agricultural properties surrounding the WPCF and an adjacent power plant.

These efforts initially included assistance in the completion of several compliance studies associated with the NPDES permit adopted in May 1999. The efforts also included a zinc and mercury source control study where West Yost developed materials on behalf of the City that were used to educate citizens about their potential source contributions of mercury to the sewer system. West Yost also negotiated an extension of the compliance deadline for construction of Title 22 filtration and disinfection facilities that was provided in the permit.

West Yost also completed several studies and is providing ongoing services in support of the NPDES permit that was adopted by the Regional Board. These efforts have included submission of a Report of Waste Discharge and NPDES Permit Application on the City’s behalf; assessment of potential dilution for surface water discharge at an alternative location; keeping an organized and regularly reviewed database of available wastewater flow and water quality data; developing statistical assessments of available data (from Reasonable Potential Analyses to more detailed statistical assessments related to permit limit derivation); development of specific effluent water quality studies to demonstrate compliance following the completion of the City’s recent tertiary upgrade project; educating and training the City in the use of EPA clean sampling techniques, and the importance of low-level analytical procedures in developing appropriate data sets; development and submission of follow-up documentation in support of the Report of Waste Discharge, including a Compliance Schedule Justification Statement; and working amicably with Central Valley Regional Water Quality Control Board staff regarding anticipated future permit requirements.

Through these efforts, West Yost identified most, if not all, of the issues that were raised during the permit renewal and was prepared to address them well in advance of permit issuance.

Ongoing services include the development of regulatory engineering studies in accordance with the permit requirements. These have included assessing appropriate receiving water temperature requirements; development of a Title 22 Engineering Report; completion of a biochemical oxygen demand organic loading study; and the assessment of potential pollution prevention measures for meeting total maximum daily load requirements for mercury.

West Yost provided regulatory compliance assistance related to the current summer irrigation reuse and biosolids land application practices. This has included the development of a site-specific operations management tool in Microsoft Excel that allows to City to easily complete the necessary data entry for monitoring report generation and day-to-day assessment of hydraulic and nutrient loadings associated with both recycled water and biosolids applications on the City’s properties.

Groundwater Study

West Yost recently completed a detailed groundwater study to assess existing conditions near the WPCF. This effort culminated in a study report that detailed a variety of natural and anthropogenic factors that affect groundwater quality in the region of the WPCF. These efforts helped to identify the appropriate locations for “background” monitoring wells. Moreover, as the State’s anti-degradation policies require the implementation of appropriate Best Practicable Treatment and Control (BPTC) measures when project-related groundwater impacts are identified, this study helped to focus these efforts and has helped to justify a significant reduction in the amount of resources that will need to be directed toward additional controls.

Evaluation of Reclamation and Reuse Alternatives

West Yost evaluated several long-term reclamation and reuse alternatives that could allow the City to achieve zero surface water discharge in the future, including agricultural and urban irrigation reuse; supplying water to a natural gas power generation facility; percolating effluent to recharge depleted aquifers; and using treated effluent to maintain a habitat wetland site. Analyses have included evaluation of reuse funding opportunities, development of a percolation disposal/treatment pilot study, support for Regional Board negotiations, and identification of preferred reuse sites adjacent to the existing WPCF.