OHA Drinking Water Services
Contact Report Details |
|||
PWS ID: | OR41 01139 | ||
PWS Name: | MIDLAND WATER ASSOCIATION | ||
Who Was Contacted and Phone: | Jim Kuhns (503) 308-3667 | ||
Contact Date: | 03/22/2011 | ||
Contacted By: | NUSRALA, JAMES (REGION 1) | ||
Contact Method/Location: | Office | ||
Assistance Type: | BOIL WATER | ||
Reasons: | SWTR N/A |
||
Details: | SUMMARY: Follow up actions - boil notice DETAILS: Jim summarized actions taken on 3/22. First he resoldered the instrument connections to the on-line 1720-C NTU meter, so that the effluent turbidity readings stabilized. He calibrated meter with non-expired Formazin. Both on-line and bench were comparable, but still reading between 1 and 1.5 NTU, higher than the raw water NTU. He then noticed that the polymer introduced a couple of days ago was feeding too much chemical, and the Streaming Current Meter (SCM) was registering a very high charge. He began using Midlands original polymer, and set feed pump on manual, feeding less chemical. SCM then read more of a neutral charge, and the effluent NTUs went down to 0.1. Chlorine residuals at plant are up to 1.4 mg/L. Jim felt root problem of high NTU and low residual chlorine was polymer pump is defective, and the high NTU was causing a high chlorine demand. ACTION NEEDED: Jim to purchase new polymer feed pump. Midland to flush high chlorine water through system, and take chlorine residual readings at far ends of distribution on Wed 3/23. DWP to ground truth effluent turbidity with bench top meter at site visit on 3/24, to verify NTUs are accurate. Midland will discuss with DWP taking coliform samples after residual restored, and NTUs to acceptable level to consider lifting boil water notice. |