OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 00466 | ||
| PWS Name: | LANGLOIS WATER DISTRICT | ||
| Who Was Contacted and Phone: | Dave Terrusa (541) 348-2142 | ||
| Contact Date: | 12/18/2007 | ||
| Contacted By: | STRASSNER, BOB (DWP) | ||
| Contact Method/Location: | Office | ||
| Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
| Reasons: | N/A N/A |
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| Details: | SUMMARY: Process CT Study. Prepare final report DETAILS: The system has needed to submit a CT Study to DWP. The study has been delayed for a period of time pending the installation of an effluent flow meter. Recently HBH was given instruction to perform studies using stored water reservoir elevations. EPA protocols indicate stored water volumes to be maintained with a 10 percent or less fluctuation during the study. The CT study performed at the system 11/29 was intended to provide a plan that would allow the district to meet the contact time requirements as well provide adequate oxidation of the raw water iron and manganese. The study recommendations to the district include pre-chlorination and free chlorine application prior to storage. Regardless of the disinfection scheme, modifications to the plant discharge piping and baffling the existing 100,000 gallon storage tank is required to meet contact time requirements during a fire flow requirement of 1000 gpm. The study includes cost estimates for baffling and a recommendation to implement a chlorine-ammonia pre disinfection process at the raw water pump station prior to the contact/settling tank. A draft of the study and a certification of results letter was prepared for review by office staff. ACTION NEEDED: Be available for technical assistance during the piloting of the recommendations. | ||