HomeMy WebLinkAbout0309.093-
Kay 1'3, 1993
THE HONORABLE CITY COUr.rCIL
Palo Alto, California
Environmental Protection Agency LEAD AND COPPER PULE -M_C'n_ P~LO
AI.TQ'S TEST RESULTS
This is an informational staff repor~ ~hi~~ provides an update on
staff efforts to comply with the EPA's L.ead and copper Rl.1Ie.
~M....k~~_P AND COP.r.ER RULE IN BRIEF
The Safe Drinking Water Action (SDWA), ''{hich 'Was enacted br
congress in 1974, gave the U.S. E~vironmental Protection Agency
(EPA) the federal authority to establish drinking water standards.
In 1975 the EPA established a primary drinking "'ater standard for
lea~ of 0.050 milligrams per liter (rog/l) and a secondary drinking
water standard for copper of 1.0 mg/l. A primary drinking water
standard is established to protect health; and, if the. standarc is
exceeded, public notification is required ..
In 1986, Cong"ress made Significant arnendmer>ts to the SDWA and
established a list of 83 contaminants for which EPA ~as to develop
drinking water standards. Lead and copper ltIere among those
contaminants. EPA responded in 1988 by proposing a rule that
included primary drinking water standards for both lead and copper
and requirO;!ments such a;:; corrosion-control treatment for water
sy$te~s. After rer.eiving n3tion~ide cc~uerts on the proposed rule
and after developing a number of drafts, EPA. announced the Lead and
Coppe~ Rule on June 7, 1991.
The basic elements of the Lead and Copper Rule are as follows:
1. All large ...,ater systems are required to test for lead and
copper at various poir:ts iri the distribution system and at
points of entry into -the distribl.'.tion system.
2. For water utilities the s:'ze of Palo Alto, 60 homes built
after 1982 having copper piping joined lJith lead solder needed
to be selected for first draw sa~pling (no water usage for at
least six hours.) The~e sa~ples are tc be taken from a faucet
inside the home. EPA used this criteria to try to identify
homes most likely to have a lead Clndjor copp.a-r problem.
CMR:309:93
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All ",ater sY$tems S€rv ing more th.an 50, 000 persor.s are also
requi~ed to do co=ro3io~ control studies ~hich must be
~ompleted by ,Tuly 1, 1990L
<!o. For all water systems excee.ding th~ action levels of 15 parts
per billion lead or 1300 parts per billio~ copp~r at the 90th
percentile cf ::a~ples tested, the foU.o'Jing actions are
required:
o optimal corrosion control,
o Public notification/education, and
o Lead service line replacement (Palo Alto has no lead
service lines).
RESULTS OF PALO ~LTO'S TE~TING
Palo Alto's first round of sampling exceeded the lead action level,
15 ppb at the 90th percentile, measuring 29.8 ppb. As required,
staff completed the second round of saJ"lpl ing in December 1992.
Results of the second round of testing, although only 16 ppb, also
exceeded the 15 ppb action level.
The EPA required all syste~s that exceeded the lead action level on
the sec'Ond round of testing to infont. customers of the adverse
health effects of lead and to explain ways people can reduce their
exposure to lead in drinking water.
Palo Alto met the public notification ~eq~irernent by including a
lead informational brochUre 'With the February util ity bill. Press
releases were also given to the local newspapers.
ClJRRENT ~T~TIJ_~
Staff completed the t.hird round of testing in early Ma:r'. The
results were 12.8 ppb lead, below the action level, 50 further
public education is not required at this time.
Pale Alto is a me~er of the Santa Clara Valley Water District's
Joint Corrosion Control Project. 'the. purpose of this project is tc
fulfill the EPA's Lead and copper Eule's corrosion testing
requirements and to evaluate the various corrosion control
treatments on the different Santa Clara County source ~aters, in
order to determine the. optimal corrosion control treatment for each
source.
Kennedy Jenks Consultants has performed an extensive review of
water quaIL ty data from both surface and ground 'Water sources
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supplying Santa Clara County. Similar ...... ater sources ...... ere grc,upeu
and seven pipe loop station locations ...... ere identified. Pipe loop
stations are a mechanical means used to evaluate the effectiveness
of corrosion inhibitors on varicus typ~s of plumbing pipes such as
copper -witI-. lead solder joints, galvanized pipe l anrj AC pipe.
Water passes through the pipe loops with various corrosion
inhibitors. At the er.d of the testing period they evaluate the
'2ffectiveness of the ir.hibitor by measuring the amounts of
corrosion in r.he various ty'pes of household piping. At each
station, four separat~ pipe loops ...... ere installed to test various
corrosion control treatments. Each of the pipe loop stations viII
be operated for eight months.
One hundred percent of Palo Alto's 'Water comes from the San
Francisco Water Department. A pipe loop station has been installed
at tt.e Water Quali't.J" Control Plant to monitor this supply. The
information gained from this station 'Will help Palo Alto evaluate
various alternatives to reduce th2 corr-osive:r.ess of its water
supply.
Respectfully submitted,
,L/..Jq..W *X,LVH{ ~$;Ef3EN~
Manager, W-G-W
Field Operations
ED J. K
II;lt rim Dife7~r .... of
(It;1 /t£~D"/'-"-
" -~~~ . ,rty Mana~er
utilities