OHA Drinking Water Services
OHA Drinking Water Services
Contact Report Details

PWS ID: OR41 00673
PWS Name: PRAIRIE CITY
 
Who Was Contacted and Phone: Georgia Patterson
Contact Date: 10/24/2007
Contacted By: BURNETT, GARY (DWP)
Contact Method/Location: Field
 
Assistance Type: OTHER REGULATORY - REGULATORY ASSISTANCE
Reasons: SWTR
Operations
 
Details: SUMMARY: Reviewed Surface Water Treatment reporting and CT calculation DETAILS: We reviewed water system operations, surface water treatment reports, and CT calculations. It was determined that the actual peak hourly flow matches the average flow due to the current system configuration and constant overflow at the reservoir. The City had been using a 2.5 multiplier to derive peak hour from average flow. The flow at 5:15 pm was 215 gpm, and an estimated 100 gpm was overflowing at the infiltration collector. The distance from the chlorination building to the first user was measured at 1.1 miles, and with 8 inch pipe, the contact volume is 15,165 gallons rather than 20,167 that had been used previously. ACTION NEEDED: A revised CT calculation data sheet was submitted to the City on 10/30/2007.