Grover Beach Water Systems Operation Support Services

The City of Grover Beach (City) owns and operates a water distribution system that includes approximately 5,200 service connections and consists of 57 miles of pipeline, four groundwater wells, three water storage tanks, one booster station, and one connection to the Lopez Water Transmission Line. To comply with Division of Drinking Water (DDW) regulations, the City must collect, analyze, and report water quality samples and other information from its drinking water sources and the distribution system on a weekly, monthly, quarterly, and yearly basis. 

To assist the City with DDW regulatory compliance, ConfluenceES is providing water quality monitoring, reporting, and engineering support services. These services include development of the water quality sampling schedule, review of water quality monitoring results and system operations information, preparation of drinking water compliance reports, and coordination with City Staff and DDW representatives. Other duties include supporting City Staff with the preparation of the annual Consumer Confidence Report (CCR), Electronic Annual Reporting (EAR), and Annual Water Supply and Demand Assessment (AWSDA) and researching new and changing regulations to advise the City on the best practices for compliance (e.g. Revised Total Coliform Rule, Lead and Copper Rule Revisions, Unregulated Contaminant Monitoring Rule V, etc.). 

ConfluenceES is currently assisting the City with water quality sampling and monitoring by collecting samples from the distribution system, groundwater wells, and blending/water storage tanks. Following the City’s Standard Operating Procedures, ConfluenceES staff is collecting free and total chlorine, total coliforms, HPC, nitrate, nitrite, general physical, pH, disinfection-by-products, orthophosphate field measurements, and water quality samples. Field measurements are collected and measured using color comparators and colorimeters. Water Quality lab samples are collected and transferred to the lab using proper handling procedures to observe temperature, holding time, and Chain of Custody (COC) requirements.     

ConfluenceES prepares monthly, quarterly and annual Division of Drinking Water water quality compliance reports for the City. These reports include a combination of water quality field logs, lab water quality results and computational analysis templates organized into an easily accessible format. Additionally, ConfluenceES developed and maintains a water quality database that includes all water quality sampling and lab results for use in the City’s Consumer Confidence and other reports. 

ConfluenceES has developed numerous Standard Operating Procedures (SOPs) and Emergency Operations Procedures (EOPs) for drinking water sampling, water quality monitoring, and water systems operations. These SOP/EOPs include documentation of standard procedures and policies and updated data collecting and recording methods to create more user-friendly monitoring and reporting methodologies.    

ConfluenceES developed an updated Bacteriological Sample Siting Plan (BSSP) to assist the City with maintaining compliance with DDW regulations and to ensure the safety of the distribution system water quality. The BSSP includes location and frequency information for routine and repeat bacteriological water quality sampling, including upstream/downstream sample locations. The upstream/downstream sample locations are used to determine if the original sample was positive due to operator or other error or if there is a larger bacteriological contamination issue. The plan additionally includes water system information, sample collection information, sampling frequency, and maps of the system which identify sample locations and additional resampling locations required after a positive coliform result.  

ConfluenceES provided support services to assist the City of Grover Beach (City) in preparing a methodology framework for its Lead Service Line Inventory (LSLI). The U.S. Environmental Protection Agency (EPA) has established a regulatory requirement for water systems to develop and maintain an inventory of service line materials, particularly focusing on lead service lines (LSLs). In California, the initial LSLI must be submitted to DDW. 

To assist the City in complying with these new regulations, ConfluenceES prepared and received DDW approval of a Stratified Random Sampling LSLI methodology for the City’s LSLI. The LSLI methodology preparation included compiling information on City water systems, water codes/standards, and property addresses accompanied by the year the property was built. Initially, addresses that were developed after the California lead ban or other standards that banned its use were marked as non-lead. A stratified random sampling methodology was then used to verify the service line material for the remaining addresses. The remaining addresses were broken into three strata by construction date. Older houses are the most likely to have lead water service lines, so sampling was weighted higher in the stratum with the oldest houses. The random sampling methodology reduced the amount of physical field verifications from 2,695 addresses to 338 addresses.