OHA Drinking Water Services
Contact Report Details |
|||
PWS ID: | OR41 00251 | ||
PWS Name: | HOPEWELL WATER COMPANY | ||
Who Was Contacted and Phone: | STEVE ALDRICH AND LLOYD (503) 868-7659 | ||
Contact Date: | 01/08/2015 | ||
Contacted By: | HENRY, ROBERT (DWP) | ||
Contact Method/Location: | Field | ||
Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
Reasons: | N/A N/A |
||
Details: | SUMMARY: Contact Time Calculations DETAILS: The Hopewell Water Company owns and operates a groundwater system which is located just north of Salem. The water company has 45 connections and an approximate population of 100. The system is a rural system with significant lengths of small diameter pipe. The primary source for the system is Nelson Spring. The Circuit Rider was contacted by the water system because they are on a boil notice due to e. Coli positives in the spring water. It is a requirement that the system show adequate inactivation through disinfection. In order to assist the system with a lifting of the boil water order, an attempt was made to determine the disinfection contact time in the pipe to the first user. Visited water system to determine length and diameter of pipe to first user. Created a simple system map to aid in the hydraulic analysis. Using a peak flow figure supplied by the water system, performed a plug flow contact time calculation on the system. It was later determined that the flow figure supplied by the water system may not represent a normal worst case scenario. ACTION NEEDED: Review flow records to determine flows for tracer testing. Complete methodology and perform tracer testing on the system. |