August 1998 Volume 21, Issue 8

Water Analysis Report Editorial

by Jeanette Weber

Date sent: Mon, 13 Jul 1998 13:39:32 -0700 (PDT)
To: thor@dnai.com
Subject: COMMENT FORM - draught board
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S I M P L E F O R M F E E D B A C K
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Name: Dr. Jeannette Von Weber, EBMUD
Email: jweber@ebmud.com
Location: Oakland

Homebrewer: YES
Brewery Designer: [comments_designer]
Draught Board: [comments_db]
Interested in Joining [comments_join]

Comments:
I checked out the water quality report interpretation
you have on your website. I want to clarify some
issues to ensure that you have appropriate information
for your members. First, EBMUD has never reported on
its annual WQ reports average chlorine residual. Such
a number would not be value to anybody since our service
area is so large and residual will vary neighbourhood to
neighbourhood. Rather, we had a target residual; prior
to the chloramination conversion, it was 1 ppm leaving
the filter plants, with no less than 0.2 ppm at the extremities of the distribution system. When we had raised the chlorine residual in 1992 to 1 ppm, we had more
taste and odour complaints due to the elevated chlorine.
The TON analysis gives information on the relative levels of compounds that lend towards objectionable odours in
the water. With the chloramination conversion, TON values have gone down because chloramine does not lend significantly to the taste and odour like chlorine. Again, we do not list  an average chloramine level in the distribution for the same  reason I state above for chlorine residual. However, we do  have a chloramine residual target for the distribution which at this point is 2 ppm as we continually tweak the system for the best target level for disinfection.

I think there is confusion on what the chlorine level is in the system. We still have a TOTAL chlorine residual in the
distribution system which consists of chloramine (or combined), our current disinfectant. Previously, the TOTAL chlorine residual would have consisted predominantly of free (uncombined) chlorine.

I am concerned that your members will become unnecessarily concerned over this issue. There is a chlorine residual in the system; we do not list a value because we have a target for which we aim for an appropriate amount of disinfectant residual; we do not report an average residual value beit free chlorine or combined because such a value would not be of use to the consumer.

I have not sufficiently clarified this issue to everybody's
satisfaction, please do not hesitate to contact me. I have listed my email address; my phone number is 510.287.1548. I had talked to your club in the month of April, I believe, so perhaps a few of you remember me.

Hope to hear from you soon!

Dr. Jeannette Von Weber


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