"file:///C:From: Jennifer Cline
Sent: Tue Jul 21 13:26:05 2015
To: Ryan Hepler
Subject: RE: Molalla uncensored and water quality.
Importance: Normal
Thank you Ryan
Jennifer Cline, P.E.
City of Molalla
Public Works Director
O: 503.759.0218
F: 503.829.3676
From: Ryan Hepler [mailto:rhepler@cityofmolalla.com]
Sent: Tuesday, July 21, 2015 1:20 PM
To: Jennifer Cline <jcline@cityofmolalla.com>
Subject: Molalla uncensored and water quality.
See attached, some of the information on this post seems misleading.
Lead and Copper sampling is done specifically at the customers faucet. These sample sites were chosen specifically at residential homes that were built at a time when they used lead solder in residential plumbing . These homes were built after 1982 and had copper plumbing with lead soldered joints. These samples are collected by the customers as a first draw sample, which means that the water has to set in the pipes for a minimum of 6 hours and then you draw your first sample into a 1000ml bottle. Even after this our 2012 sample highest lead sample was 0.010 ppm, and our highest copper sample was 0.113 ppm. The EPA MCL (maximum contaminate level) is 0.015 ppm lead and 1.3 ppm copper, the 90th percentile results were 0.007 lead 0.084 copper. So we did not exceed this and we do not need to sample every year as posted in the comments. We sample every 3 years. When we report Lead and Copper sampling on our consumer report we report as 90th percentile as does every water system. The 90th percentile lead and copper levels shall be computed as follows: The results of all lead or copper samples taken during a monitoring period shall be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result shall be assigned a number, ascending by single integers beginning with the number 1 for the sample with the lowest contaminant level. The number assigned to the sample with the highest contaminant level shall be equal to the total number of samples taken. The number of samples taken during the monitoring period shall be multiplied by 0.9. The contaminant concentration in the numbered sample yielded by this calculation is the 90th percentile contaminant level.
The comments are misleading and make is sound as if the 90th percentile numbers exceed the EPA MCL’s, which they don’t. As for late reporting violations, these occurred most likely because the state received our reporting data later than the 10th of the month, however I was not here at the time. I did look into it and the late reporting violations have been returned to compliance.
https://yourwater.oregon.gov/violsum.php?pwsno=00534
Ryan Hepler
City of Molalla
Water Treatment Operator
503-829-5408