Golden State Water Company Del Monte Well 4 Arsenic Removal

Claremont, CA


PACE was hired by Golden State Water Company (GSWC) to provide professional consulting services for Del Monte Well No. 4 arsenic reduction project in Claremont, CA. The Claremont Water System is owned and operated by GSWC and includes the Del Monte Supply Wells 1, 2 and 4 located on College Avenue. The raw water from Well 4 contains varying arsenic content, generally exceeding the state MCL of 10 µg/L, with typical concentrations ranging from 20 to 40 µg/L.


Treatment and blending were required to reduce the average arsenic concentration to less than 8 µg/L. PACE proposed a plan including six operation scenarios and testing schedules for Well 4 based on the key findings from the site visit at the Del Monte storage tank and booster station plant. The plan also included installation concepts for the tank mixing system, analysis of tank inlet/outlet, as well as the water quality testing protocols for properly monitoring the system performance, parameters including dissolved oxygen, oxidation-reduction potential, total dissolved solids, pH, color, alkalinity, total arsenic, dissolved arsenic, total iron, dissolved iron, total manganese, dissolved manganese, total chlorine, free chlorine, total volatile compounds, total organic carbon, ammonia and sulfide.


Key Features:

  • Laboratory water quality analysis and piloting
  • Operations augmentation strategies
  • Wellhead treatment system

Golden State Water Company

Advanced Water Quality / Piloting