SCH Number 2018112050

Project Info

Title

Supplemental Mitigated Negative Declaration - Keyes 1, 2, 3 TCP Mitigation Project

Description

This is a Supplemental Initial Study / Mitigated Negative Declaration to the Keyes CSD’s Keyes 1, 2, 3 – TCP Mitigation Project (Approved Project), which includes a treatment system to remove the pesticide impurity 1, 2, 3 – Trichloropropane (TCP) from its water supply. The original Approved Project included two components: 1) Granular Activated Carbon (GAC) Treatment at Well 8, Well 9, and Well 10. This component will centralize TCP treatment at Wells 8, 9, and 10. Two trains and a 40,000 gallon backwash tank will be constructed at Well 8. Three trains will be constructed at Well 9. Four trains and a 60,000 gallon backwash tank will be constructed at Well 10. 2) Water Transport from Well 7 to Well 10. Because physical space at Well 7 cannot accommodate GAC infrastructure, this component involves conveying raw ground water from Well 7 to Well 10 for TCP treatment. Approximately 2,532 linear feet of 6-inch pipeline will be installed below existing roads between Well 7 and Well 10. After filing the Notice of Determination for the Approved Project, minor changes were made to the Project which included removing a previously-planned backwash holding tank at Well 9 and installing a 150,000 gallon backwash pond adjacent to the Well 9 site. Additional modifications consist of changes to tank sizes at Wells 7, 8 and 10. These additional components were evaluated in the Supplemental IS/MND. Existing water service will not be significantly impacted during construction.

4 documents in project