HomeMy WebLinkAbout08 Public Health Goals 2021• California Health and Safety Code, Section 114670(b) requires public
water systems with greater than 10,000 service connections to
provide a Public Health Goals Report every three years
• The report is to outline water quality contaminants for which Public
Health Goals (PHG) have already been established, and have been
exceeded during the previous monitoring period
• The PHG report must also include information regarding the
contaminants, their potential health effects, and estimated costs to
reduce exposures below the PHG
• Following the completion of the PHG report, public water systems
must provide an opportunity for service area customers to review and
comment through the public hearing process
• The
District's
2019 PHG
report
was presented at
a public hearing held
at a
regularly
scheduled
board
meeting in June,
2019
• The
District's 2021 Public Health Goals
report
has been prepared and
will
be submitted to the California State
Water
Resources Control
Board (SWRCB) for review
• A copy of the PHG report has been included with the staff report
• Public Health Goals (PHG) are set by the California Office of
Environmental Health Hazard Assessment (OEHHA) and are based
solely on public health risk considerations
• When establishing PHG standards, the OEHHA does not consider
factors such as analytical detection capabilities, available treatment
technologies, or cost
• PHG are not enforceable and are strictly intended to be health goals
• For the District's 2022 PHG report, all water quality data collected
from the potable water system between 2019 and 2021 were
considered
• For the purposes of preparing the report, staff used guidelines
published by the Association of California Water Agencies
(ACWA) and the SWRCB
Arsenic
• A semi -metal element naturally occurring in the earth's crust, found
in a variety of solid phases including volcanic rock.
• The element is commonly found in sedimentary soils due to
migration and accumulation through weathering.
• The mobility of arsenic in groundwater is highly dependent upon the
physical and chemical properties of the aquifer
Arsenic (continued)
• The SWRCB Maximum
Contaminant Level (MCL) for arsenic is 10
parts per billion (ppb) and the Public Health Goal is .004 ppb
• The District has detected arsenic in 6 of the 12 groundwater wells
above the PHG limit of .004 ppb
• Glenshire Drive Well 8.9ppb
• Martis Valley Well 9.9ppb
• Airport Well 6.2ppb
• Old Greenwood Well 2.6ppb
• Prosser Village Well 2.7ppb
• Sanders Well 8.6ppb
Best Available Technology (BAT)
• Fixed bed adsorption systems are a filtration technology commonly
utilized in efforts to reduce arsenic levels in potable water sources
• The estimated cost to install treatment systems of this nature at all 6
wells where arsenic has been detected is approximately $8M for initial
construction, with an additional $6.9M estimated annual O&M
• This would result in an assumed annual estimated operating cost of
approximately $550 per customer
Recommendation for Further Action
• Drinking water quality for the Truckee Donner Public Utility District meets
or exceeds all SWRCB and United States Environmental Protection Act
standards
• In order to further reduce contaminant levels, that currently meet the
health based MCLs established by the SWRCB and USEPA, an extensive
range of costly testing and construction would be required
• Based on the uncertainty of available treatment technologies in reducing
arsenic and lead levels in water already below the MCL, and the
significant costs associated with testing and implementation, no further
action is recommended at this time
There is no direct fiscal impact associated with this item
Conduct a
Public Hearing to
receive input
from the public
regarding
the
District's 2022
Public
Health
Goals
Report