OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00055 | ||
PWS Name: | ASTORIA, CITY OF | ||
Who Was Contacted and Phone: | Jim Hatcher (503) 325-3524 | ||
Contact Date: | 03/09/2016 | ||
Contacted By: | HOFELD, EVAN (REGION 1) | ||
Contact Method/Location: | Office | ||
Assistance Type: | OTHER REGULATORY - REGULATORY ASSISTANCE | ||
Reasons: | Disinfection Byproducts None |
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Details: | SUMMARY: DBP LRAA for 2015 below MCL DETAILS: A review of DBP LRAA calculated quarterly in 2015 for the City of Astoria demonstrated that the system has been consistently below the MCL for both TTHM and HAA5. Quarterly TTHM LRAA calculations in 2015 ranged from 0.046 - 0.057 mg/l and HAA5 LRAA ranged from 0.051 - 0.057 mg/l. LRAA for TTHM calculated from 3rd quarter 2014 - 1st quarter 2016 ranged from 0.045 - 0.057 mg/l. LRAA for HAA5 calculated quarterly from 3rd quarter 2014 to 1st quarter 2016 ranged from 0.051 to 0.057 mg/l. Although the results are below the MCL for HAA5, they have been close to the MCL of 0.060 mg/l. Jim said the City still plans on pursuing the development of the Spur 14 source, which is believed to have lower TOC water. Jim and I discussed future reductions in DBP monitoring from quarterly to annual sampling as a surface water system serving 9,516 people, which would not be possible until the LRAA dropped below half the MCL for both TTHM and HAA5 at all locations and the raw water TOC was less than or equal to 4 mg/l based on a years worth of monthly raw water TOC monitoring. ACTION NEEDED: System to continue quarterly DBP sampling. |