Requirements for PID’s National Pollution Discharge Elimination System (NPDES) permit are expected to change; this project will help the district best meet those new requirements.
An NPDES permit is required to return water generated by PID’s backwash and flushing processes into Magalia Reservoir. When the permit was last renewed, the new discharge limits placed on levels of aluminum and dichlorobromomethane meant that the district’s current treatment processes could no longer meet the requirements.
Aluminum comes from a product we use as a coagulant to encourage dirt particles to stick together for better clarification. Dichlorobromomethane is a byproduct of our chlorination prior to filtration. The chlorine reacts with organic material and results in the formation of dichlorobromethane.
|Project Phase||Previous Fiscal Year Expenses||Fiscal Year 15/16||Fiscal Year 16/17||Fiscal Year 17/18||Fiscal Year 18/19||Fiscal Year 19/20||Total|
PID's board considered these alternatives
Option 1—Recycle the process water with a new treatment system and no longer discharge water—thus eliminating the need for a required NPDES.
Option 2—Work with the state Regional Board to establish appropriate discharge limits that ensure discharged water is not harmful to the environment or to humans and renew the NPDES permit under that new understanding. Additionally, the new NPDES permit will guide the district in planning construction of necessary treatment or recycling facilities.
PID’s board voted to pursue Option 2 and has hired a consultant with successful experience in NPDES review and renewal to assist in this process.
Benefits to PID and its Customers
Option 2 can conceivably save the district and its customers hundreds of thousands of dollars in construction and operating costs.
Anticipated Project Timeline
- pdf June 2012 - Board memo from Treatment Plant Superintendent (50 KB)
- pdf June 2013 - Alternatives Evaluation Report (Draft) (1.31 MB)
- pdf March 2014 - Alternatives Evaluation Report (1.63 MB) (Final)
- pdf March 2014 - Constructed Wetlands Evaluation Report (1.81 MB)
- pdf July 2014 - Life Cycle Cost Analysis (1.84 MB)
- pdf May 2015 - Pilot Study Results (6.48 MB) (Detailed)
- pdf May 2015 - Pilot Study Results (1.34 MB) (Summary)
- pdf February 2016 - Preliminary Design Report (39.07 MB)
- pdf April 19, 2017 - Board votes to renew NPDES permit (2.76 MB)
- pdf June 21, 2017 - Update on RFP for NPDES permit renewal assistance (568 KB)
- pdf September 20, 2017 - Board authorizes agreement with Waterworks Engineers (2.88 MB)
- pdf January 2018 - NPDES Progress Report (194 KB)
Project details updated February 2018