OHA Drinking Water Services
OHA Drinking Water Services
Contact Report Details
PWS ID: OR41 00042
PWS Name: ANTELOPE, CITY OF
 
Who Was Contacted: Jeannie Adams/Rodney Shanks
Contact Phone: 541-699-9605
Contact Date: 08/11/2021
Contacted By: CIVIL WEST ENGINEERS, INC (DWP)
Contact Method/Location: Field
 
Assistance Type: CIRCUIT RIDER ASSISTANCE
 
Details: Background/Problem Identification:
Jeannie Adams called and indicated that there were issues with their chlorination system. Residual testing is done every two days with a “pool kit”, and it appears sometimes the levels are too high, other times, too low.

Assistance Provided:
The circuit rider made a site visit and discussed the water system’s issues at length. The issue with the fluctuation in the chlorine residual is likely rooted in the fact that an incorrect test kit is being used, along with an un-diluted sodium hypochlorite mix with very slow pump feed rates.

The circuit rider recommends that the water system use a HACH Pocket Colorimeter II or similar testing device (HACH DR300) to more accurately monitor the chlorine residual in distribution. Further, we recommend that the operator dilute the chlorine mix 10:1 with water and “turn-up” the chlorinator as needed to match the dilution.

Currently the operator is using straight 6.25% hypochlorite with settings of 18% for both the stroke length and speed on the chemical dosing pump. A residual of 0.30ppm was measured at the kitchen sink of the Adams residence. The circuit rider recommends running a 10:1 mix in the 55 gallon day tank, at this dilution we estimate that (if linear) the chemical dosing pump should be set at ~60% on both stroke length and speed. The circuit rider provided a hardcopy spreadsheet for day tank mixing that shows the amounts of chlorine and water that need to be added to top off the tank for any given starting tank level from 0-50 gallons.

Follow-Up Actions Needed:
The circuit rider is available to assist as needed.

Technical Reports to be Prepared and Expected Timeframe:
N/A.