sr-022481-11bSanta Monica, California, February 17, 1981
1 I -(3
T0: Mayor and City Council
FEB 2 4 1981
FROM: City Staff
SUBJECT: Approval of Draft Letter Regarding Quality of Drinking Water
Introduction
This report recommends the attached draft letter be approved for mailing to
residents and businesses in Santa Monica who are water customers.
Background
On August 12, 1980, the City Council approved. the printing and mailing of
information to all water users to explain certain items regarding water
quality. The City Attorney issued an opinion, in a staff report, on
October 29, 1980 (Item 11-C), stating such a letter was authorized and
previously budgeted funds could be used to fund the mailing.
The staff has developed the attached letter with the help of interested
citizens.
Recommendation
It is recommended the City Council authorize the mailing of the attached
letter.
Prepared by: Stan Scholl
1/-~
FE$. Z 4 f98l;
Dear Resident:
No doubt you are aware of the recent detection of trichlorethylene (TCE)-and
the presence of trihalomethane (THM) in the water in, Southern California. The
City Council has chosen to inform you of the facts and answers to some obvious
pertinent questions so that misunderstandings may be alleviated and you may decide
for yourself whether or not to continue using the City furnished water supply.
Question: Exactly what is TCE?
A volatile industrial solvent which is listed 6y the National Academy of Sciences
as one of the chemical substances that has produced cancer in laboratory animals
and is consequently suspected as a carcinogen in humans. In the work place and
industrial environments, exposure from handling or breathing of TCE, (greater than
100,000 parts per billion ppb) has led to serious damage to health in humans.
Question: What is the problem with TCE in Sahta Monica Water?
Traces of TCE were found in two of the City's water wells, and the City took
immediate steps to control and reduce those levels. The two wells have not been used
for several months. The amount of TCE which reached consumers (less than 5 ppb) when
the wells were in use did not exceed California Department of Health or Environmental
Protection Agency limitations. Water from the affected wells was aerated and blended
with other water as a normal part of the water treatment process before being allowed
to enter the distribution system.
Question: What are the health risks connected with water containing TCE?
EPA projects that water containing 4.5 ppb of TCE will increase a person's risk of dying
of cancer by one chance in 100,000, if consumed at the rate of 2 liters a day for 70 years.
The risks are compounded when the drinking water also contains other harmful organic
substances. Certain groups which may wish to take greater precaution include
pregnant women and young children.
Page 2
Question: What are Trihalomethanes (THMs)
Unlike TCE which. is an industrial product found in some well water, THMs are a
by-product found in imported water which has been chlorinated. Surface water supplies
such as the MWD supply in Northern California.(as it travels through the delta) picks
up organic materials from weeds, .grass, and leaves. When the organic material comes in
contact with chlorine during the disinfecting process THMs-are formed. Chloroform is
the trihalomethane found most often in water.
Ouestion: How much THM is in S
associated with this
ter and what are the health risks
The MWD water frequently contains from 80-120 parts per billion of THM. Santa Monica
blends its well water with this in varying amounts depending on the zone within the
City. The resulting water contains from 30-100 parts per billion THMs. The EPA has
stated that the maximum contaminant level (MCL) which may not be exceeded by 1982 as
100 parts per billioh. We believe the-.THM proba em is greater than. the TGE
problem. The effects of chloroform on the human body are still under study but one test
has found high doses can be carcinogenic to rats and mice.
Question: What is the City doing to ensure the water supply is within safe limits?
The City samples and tests the water daily for residual chlorine levels and weekly for
bacteriological water quality, general mineral content, and general physical parameters.
Since the shutdown of the two wells there is no TCE in the water. There are levels of
THMs in the water which occasionally exceed the proposed 1982 limits of the EPA (100 ppb).
The THM problem is related to the purchased Metropolitan Water District water. All of
the cities in Southern California which use MWD water (almost all of Southern California)
are experiencing the same problems as Santa Monica is since all use the MWD water. Santa
Monica has requested the MWD through its representative on the MWD Board to begin to take
steps to control the THM levels.
Page 3
Normally Santa Monica pumps about 60% well water and uses about 40% MWD water. It
is ironic that as the City has controlled its TCE level by temporarily closing two
wells, it has necessarily purchased larger amounts (approximately 65% rather than
40%) of MWD water, thus has increased the THM levels in the delivered water.
Question: What can be expected in the future?
Part of the answer lies in research technology. The development of better
scientific equipment is showing trace elements (such as TCE)- that were entirely
undetected or not even suspected a few years ago. As analytical techniques improve,
new and unforeseen problems could possibly 6e detected. What the City can assure
you is that. we will continue to take every precaution to deliver you the best
water available, and will. continue to monitor and test that water with the best
available analytical technology, and wi11 notify you if the water fails in any
way to meet Federal, State, or our own stringent requirements. The safety of our
public water supply is our business, and more than 1-,000 separate quality and
safety tests are conducted on our water each month in the City's state-approved
water laboratory.
Question: What are the alternatives?
Simply stated, if you're not convinced that the water is safe, there are always
alternatives.
Some are:
1. Boil the water. TCE and THM°have flower boiling points than water, so this is most
effective in removing it from the water.
2. Use commercially bottled water.
3. Investigate (carefully} the various makes and types of filters and treatment
units which fit on your sink or home plumbing.*
* The City, as a matter of policy, will neither approve or disapprove any commercial
product.
Page 4
Finally, this letter is not to alarm you, but rather to inform you of the facts
as they exist so that you make your own decision as to the use of City water.
Additional information on this subject is on the back page of the fall Issue
of the Seascape. We will continue to keep you informed through the local news
media or you may contact City Hall at 393-9975, extension 216.
Bohn Bambrick
Mayor