HomeMy WebLinkAbout12 Public Health Goals Agenda Item # 12
Public Utility Distr ct
ACTION
To: Board of Directors
From: Ed Taylor
Date: March 18, 2009
Subject: Schedule a Public Hearing to Accept Input Regarding Public Health
Goals
1. WHY THIS MATTER IS BEFORE THE BOARD
Only the Board can schedule a date for a public hearing.
2. HISTORY
SB1307 (Calderone-Sher; effective 1-1-97) added new provisions to the California
Health and Safety Code which mandate that a report be prepared by July 1, 1998 and
every three years thereafter. This report is required for all water systems with more
than 10,000 service connections. The 3 year reporting cycle and the report has now
due. The attached report is intended to provide information to the public in addition to
Annual Water Quality Reports mailed to each customer.
3. NEW INFORMATION
The Public Health Goal report has been completed (Attachment 1) and is now ready
for public hearing portion of the State mandate. The State law requires that a public
hearing be held for the purpose of accepting public comment on the report. TDPUD
water system complies at this time with all of the health-based drinking water
standards and maximum contaminants levels required by the California Department
of Public Health, and United States Environmental Protection Agency.
4. FISCAL IMPACT
There is no direct fiscal impact associated with this action.
5. RECOMMENDATION
Schedule a public hearing on April 1, 2009 regular Board meeting for accepting and
I)d
ondi public comment on the Public Health Goal Report.
aylor Michael D. Holey
Water Utility Manager General Manager
Attachment 1
PUBLIC HEALTH GOAL REPORT
FOR
TRUCKEE DONNER PUBLIC UTILITY DISTRICT
Background:
Provisions of the California Health and Safety Code specify that larger (>10,000 service
connections) water utilities prepare a special report by July 1, 2004 if their water quality
measurements have exceeded any Public Health Goals (PHGs). PHGs are non-
enforceable goals established by the Cal-EPA's Office of Environmental Health Hazard
Assessment (OEHHA). The law also requires that where OEHHA has not adopted a PHG
for a constituent, the water suppliers are to use the MCLGs adopted by USEPA. Only
constituents which have a California primary drinking water standard and for which either a
PHG or MCLG has been set are to be addressed.
There are a few constituents that are routinely detected in water systems at levels usually
well below the drinking water standards for which no PHG nor MCLG has yet been
adopted by OEHHA or USEPA including Total Trihalomethanes. These will be addressed
in a future required report after a PHG has been adopted.
The new law specifies what information is to be provided in the report.
If a constituent was detected in the District's water supply between 2006 and 2008 at a
level exceeding an applicable PHG or MCLG, this report provides the information required
by the law. Included is the numerical public health risk associated with the MCL and the
PHG or MCLG, the category or type of risk to health that could be associated with each
constituent, the best treatment technology available that could be used to reduce the
constituent level, and an estimate of the cost to install that treatment if it is appropriate and
feasible.
What Are PHGs?
PHGs are set by the California Office of Environmental Health Hazard Assessment
(OEHHA) which is part of Cal-EPA and are based solely on public health risk
considerations. None of the practical risk-management factors that are considered by the
USEPA or the California Department of Public Health (DPH) in setting drinking water
standards (MCLs) are considered in setting the PHGs. These factors include analytical
detection capability, treatment technology available, benefits and costs. The PHGs are not
enforceable and are not required to be met by any public water system. MCLGs are the
federal equivalent to PHGs.
Water Quality Data Considered:
All of the water quality data collected by our water system between 2006 and 2008 for
purposes of determining compliance with drinking water standards was considered. This
data was all summarized in our 2006, 2007, and 2008 Annual Water Quality Reports which
were mailed to all of our customers in June of the following year.
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Attachment 1
Guidelines Followed:
The Association of California Water Agencies (ACWA) formed a workgroup which
prepared guidelines for water utilities to use in preparing these newly required reports. The
ACWA and California Department of Public Health guidelines were used in the preparation
of our report.
Best Available Treatment Technology and Cost Estimates:
Both the USEPA and CDHS adopt what are known as BATs or Best Available
Technologies which are the best known methods of reducing contaminant levels to the
MCL. Costs can be estimated for such technologies. However, since many PHGs and all
MCI-Gs are set much lower than the MCL, it is not always possible, nor feasible, to
determine what treatment is needed to further reduce a constituent downward to or near
the PHG or MCLG, many of which are set at zero. Estimating the costs to reduce a
Constituent to zero is difficult, if not impossible because it is not possible to verify by
analytical means that the level has been lowered to zero. In some cases, installing
treatment to try and further reduce very low levels of one constituent may have adverse
effects on other aspects of water quality.
Constituents Detected That Exceed a PHG or a MCLG:
The following is a discussion of Arsenic, Coliform Bacteria, and Lead that was detected in
our drinking water system at levels above the PHG, or if no PHG, above the MCLG.
Arsenic: The MCL for arsenic is 10 ppb, the PHG and MCLG for arsenic is 0.0004 ppb.
We have detected arsenic in 7 of our 12 wells, Glenshire Drive Well at 13 ppb, Martis
Valley Well at 8.6 ppb, Airport Well at 8 ppb, Prosser Village at 5 ppb, Old Greenwood
Well at 5 ppb, Sanders Well at 9.1 ppb and Southside Well #2 at 1.5 ppb. The category of
health risk associated with arsenic, and the reason that a drinking water standard was
adopted for it, is that people who drink water containing Arsenic above the MCL throughout
their lifetime could experience an increased risk of getting cancer. The Office of
Environmental Health Assessment (part of California Environmental Protection Agency)
has set the PHG at 4 ppt (0.0004 ppb). The PHG is based on a level that will result in not
more than 1 excess cancer in 1 million people who drink 2 liters daily of this water for 70
years. The actual cancer risk may be lower or zero. The BAT that we are using for this
report to lower the level below the MCL to 4 ppt is a fixed bed adsorption system. These
are the same systems we are already using at Northside Well which has an arsenic level
of 38 ppb before treatment and a post treatment level of N/D to 1.5 ppb, and the
Hirschdale Well which has a pre treatment level of 40 ppb and post treatment level of N/D
to 9 ppb. The estimated cost to install and operate such a treatment system on all 7 Wells
would reliably reduce the Arsenic level to 4 ppt and would cost approximately $6,831,000
for the initial construction with an additional O&M cost of $5,471,400 per year. This would
result in an assumed increased cost for each customer of $492 per year.
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Attachment 1
Coliform Bacteria:
During 2006 and 2007, we collected between 40 and 50 samples each month for Coliform
analysis. Occasionally, a sample was found to be positive for Coliform Bacteria. Check
samples were negative and follow up action was taken. A maximum of 2.5% of these
samples were positive in any month. In 2008 there were no positive samples.
The MCL for coliform is 5% positive samples of all samples per month and the MCLG is
zero. The reason for the coliform drinking water standard is to minimize the possibility of
the water containing pathogens which are organisms that cause waterborne disease.
Because coliform is only a surrogate indicator of the potential presence of pathogens, it is
not possible to state a specific numerical health risk. While USEPA normally sets MCLGs
"at a level where no known or anticipated adverse effects on persons would occur', they
indicate that they cannot do so with coliforms.
Coliform bacteria are an indicator organism that are ubiquitous in nature and are not
generally considered harmful. They are used because of the ease in monitoring and
analysis. If a positive sample is found, it indicates a potential problem that needs to be
investigated and follow up sampling done. It is not at all unusual for a system to have an
occasional positive sample. It is difficult, if not impossible, to assure that a system will
never get a positive sample.
TDPUD adds chlorine at our sources to assure that the water served is micro biologically
safe. The chlorine residual levels are carefully controlled to provide the best health
protection without causing the water to have undesirable taste and odor or increasing the
disinfection byproduct level. This careful balance of treatment processes is essential to
continue supplying our customers with safe drinking water.
Other equally important measures that we have implemented include: an effective cross-
connection control program, maintenance of the disinfectant residual throughout our
system, an effective monitoring and surveillance program and maintaining positive
pressures in our distribution system. Our system has already taken all of the steps
described by CDHS as "best available technology" for coliform bacteria in Section 64447,
Title 22, CCR.
Lead
There is no MCL for Lead. Instead the 90th percentile value of all samples from household
taps in the distribution system cannot exceed an Action Level of 0.015 mg/I for lead .The
PHG for lead is 0.002 mg/l. Lead and copper enter drinking water primarily through
plumbing materials on the customer's side of the water service. There is no MCL for Lead
in source water from wells.
Exposure to lead and copper may cause health problems ranging from stomach distress to
brain damage. On June 7, 1991, USEPA published a regulation to control lead and copper
in drinking water. This regulation is known as the Lead and Copper Rule (also referred to
as the LCR or 1991 Rule) which has also been adopted by CDPH. Numerical health risk
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Attachment 1
data on lead has not yet been provided by OEHHA, the State agency responsible for
providing that information.
All of our source water samples for lead in 2006, 2007, and 2008 were less than the PHG.
Based on extensive sampling of our distribution system in 2007, our 90th percentile value
for lead was 0.004 mg/I which was over the PHG of 0.002 mg/L.
The treatment technique for the rule requires systems to monitor drinking water at
customer taps. If lead concentrations exceed an action level of 15 ppb or copper
concentrations exceed an action level of 1.3 ppm in more than 10% of customer tap
samples, the system must undertake a number of additional actions to control corrosion. If
the action level for lead is exceeded, the system must also inform the public about steps
they should take to protect their health and may have to replace lead service lines under
their control.
Our water system is in full compliance with the Federal and State Lead and Copper Rule.
Based on our extensive sampling, it was determined according to State regulatory
requirements that we meet the Action Levels for Lead. Therefore, we are deemed by
CDHS to have "optimized corrosion control' for our system. In general, optimizing
corrosion control is considered to be the best available technology to deal with corrosion
issues and with any lead or copper findings. We continue to monitor our water quality
parameters that relate to corrosivity, such as the pH, hardness, alkalinity, total dissolved
solids, and will take action if necessary to maintain our system in an "optimized corrosion
control' condition.
Since we are meeting the optimized corrosion control' requirements, it is not prudent to
initiate additional corrosion control treatment as it involves the addition of other chemicals
and there could be additional water quality issues raised. Therefore, no estimate of cost
has been included.
RECOMMENDATIONS FOR FURTHER ACTION:
The drinking water quality of the Truckee Donner Public Utility District at this time meets all
State of California, Department of Public Health and USEPA drinking water standards set
to protect public health. To further reduce the levels of the constituents identified in this
report that are already below the health-based Maximum Contaminant Levels established
to provide "safe drinking water", additional costly treatment processes would be required.
The effectiveness of the treatment processes to provide any significant reductions in
constituent levels at these already low values is uncertain. The health protection benefits
of these further hypothetical reductions are not at all clear and may not be quantifiable.
Therefore, no action is proposed.
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