OHA Drinking Water Services
OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 00554 | ||
| PWS Name: | NEHALEM, CITY OF | ||
| Who Was Contacted and Phone: | Don Davidson (503) 801-0955 | ||
| Contact Date: | 12/19/2011 | ||
| Contacted By: | KALISH, FRED (REGION 1) | ||
| Contact Method/Location: | Office | ||
| Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
| Reasons: | Disinfection Byproducts Operations |
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| Details: | SUMMARY: High DBPs in December Sampling DETAILS: Called Don this morning to discuss results of 12/6/11 DBP sampling results - both TTHM and HAA5 were significantly elevated compared with previous results. Although the results are high, they are not MCL violations since the MCL is based on RAA and the calculated RAA with these latest results were below the MCL (new RAA: TTHM - 0.0562 ppm-- HAA5 - 0.0583). Don indicated that there may be a few factors relating to the elevated levels of the DBPs: the distribution line were the sample is collected has not been flushed for some time, he has been adding some disinfectant upstream of cartridge filters to reduce growth on filters, he has been running the chlorine residual higher lately. There also may have been higher raw water NTUs due to storm events prior to sampling. ACTION NEEDED: Don needs to flush the distribution lines, and reduce the potential for DBP formation by discontinuing prechlorination of cartridge filters, and lowering distribution system chlorine residuals. | ||
| Associated Alerts: | CHEM5183 - 12/19/2011 - TOTAL HALOACETIC ACIDS (HAA5) , TTHM CHEM5183 - 12/19/2011 - TOTAL HALOACETIC ACIDS (HAA5) , TTHM |
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