2014 CCR
Consumer Confidence Report
2014 Consumer Confidence Report
Water System Name: Best Road MWC Report Date: May 14, 2015
We test the drinking water quality for many constituents as required by state and federal regulations. This report shows
the results of our monitoring for the period of January 1 -
Este informe contiene información muy importante sobre su agua potable. Tradúzcalo ó hable con alguien que lo
entienda bien.
Type of water source(s) in use: Groundwater
Name and general location of source(s): Wells 1 and 2 are located on John Smith Road, approximately 1 mile from Fairview Rd.
Drinking Water Source Assessment information: See attached; dated August 2002 (Well #1 & #2).
Time and place of regularly scheduled board meetings for public participation: 7pm, the 3rd Tuesday at San Benito Land & Title Company, 260 Tres Pinos Road, Hollister, CA 95023.
For more information, contact: Garry Solmonson Phone: (831).634.0144
TERMS USED IN THIS REPORT
Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as is economically and technologically feasible. Secondary MCLs are set to protect the odor, taste, and appearance of drinking water.
Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the U.S. Environmental Protection Agency (USEPA).
Public Health Goal (PHG): The level of a contaminant in drinking water below which there is no known or expected risk to health. PHGs are set by the California Environmental Protection Agency.
Maximum Residual Disinfectant Level (MRDL): The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
Maximum Residual Disinfectant Level Goal: (MRDLG): The level of a drinking water disinfectant ppt: parts per trillion or nanograms per liter (ng/L) below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use
of disinfectants to control microbial contaminants.
Primary Drinking Water Standards (PDWS): MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements, and water treatment requirements.
Secondary Drinking Water Standards (SDWS): MCLs for contaminants that affect taste, odor, or appearance of the drinking water. Contaminants with SDWSs do not affect the health at the MCL levels.
Treatment Technique (TT): A required process intended to reduce the level of a contaminant in drinking water.
Regulatory Action Level (AL): The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.
Variances and Exemptions: State Board permission to exceed an MCL or not comply with a treatment technique under certain conditions.
ND: not detectable at testing limit.
ppm: parts per million or milligrams per liter (mg/L)
ppb: parts per billion or micrograms per liter (µg/L)
ppt: parts per trillion or nanograms per liter (ng/L)
ppq: parts per quadrillion or picogram per liter (pg/L)
pCi/L: picocuries per liter (a measure of radiation).
The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.
Contaminants that may be present in source water include:
• Microbial contaminants, such as viruses and bacteria, that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
• Inorganic contaminants, such as salts and metals, that can be naturally-occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
• Pesticides and herbicides, that may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.
• Organic chemical contaminants, including synthetic and volatile organic chemicals, that are by-products of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural application, and septic systems.
• Radioactive contaminants, that can be naturally-occurring or be the result of oil and gas production and mining activities.
In order to ensure that tap water is safe to drink, the USEPA and the State Water Resources Control Board (State
Board) prescribe regulations that limit the amount of certain contaminants in water provided by public water systems.
State Board regulations also establish limits for contaminants in bottled water that provide the same protection for public
health.
Tables 1, 2, 3, 4, 5, 7, and 8 list all of the drinking water contaminants that were detected during the most recent sampling for the constituent. The presence of these contaminants in the water does not necessarily indicate that the water
poses a health risk. The State Board allows us to monitor for certain contaminants less than once per year because the
concentrations of these contaminants do not change frequently. Some of the data, though representative of the water
quality, are more than one year old.
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Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the U.S. Environmental Protection Agency (USEPA).
Public Health Goal (PHG): The level of a contaminant in drinking water below which there is no known or expected risk to health. PHGs are set by the California Environmental Protection Agency.
Maximum Residual Disinfectant Level (MRDL): The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
Maximum Residual Disinfectant Level Goal: (MRDLG): The level of a drinking water disinfectant ppt: parts per trillion or nanograms per liter (ng/L) below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use
of disinfectants to control microbial contaminants.
Primary Drinking Water Standards (PDWS): MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements, and water treatment requirements.
Secondary Drinking Water Standards (SDWS): MCLs for contaminants that affect taste, odor, or appearance of the drinking water. Contaminants with SDWSs do not affect the health at the MCL levels.
Treatment Technique (TT): A required process intended to reduce the level of a contaminant in drinking water.
Regulatory Action Level (AL): The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.
Variances and Exemptions: State Board permission to exceed an MCL or not comply with a treatment technique under certain conditions.
ND: not detectable at testing limit.
ppm: parts per million or milligrams per liter (mg/L)
ppb: parts per billion or micrograms per liter (µg/L)
ppt: parts per trillion or nanograms per liter (ng/L)
ppq: parts per quadrillion or picogram per liter (pg/L)
pCi/L: picocuries per liter (a measure of radiation).
The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-
Contaminants that may be present in source water include:
• Microbial contaminants, such as viruses and bacteria, that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
• Inorganic contaminants, such as salts and metals, that can be naturally-
• Pesticides and herbicides, that may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.
• Organic chemical contaminants, including synthetic and volatile organic chemicals, that are by-
• Radioactive contaminants, that can be naturally-
In order to ensure that tap water is safe to drink, the USEPA and the State Water Resources Control Board (State
Board) prescribe regulations that limit the amount of certain contaminants in water provided by public water systems.
State Board regulations also establish limits for contaminants in bottled water that provide the same protection for public
health.
Tables 1, 2, 3, 4, 5, 7, and 8 list all of the drinking water contaminants that were detected during the most recent sampling for the constituent. The presence of these contaminants in the water does not necessarily indicate that the water
poses a health risk. The State Board allows us to monitor for certain contaminants less than once per year because the
concentrations of these contaminants do not change frequently. Some of the data, though representative of the water
quality, are more than one year old.
_____________________________________________________________________________________________________________
TABLE 1 – SAMPLING RESULTS SHOWING THE DETECTION OF COLIFORM BACTERIA
Microbiological Contaminants Highest No. No. of months in
(complete if bacteria detected) of Detections violation MCL MCLG Typical Source of Bacteria
Total Coliform Bacteria (In a mo.) 0 More than 1 sample in a 0 Naturally present in the
0 month with a detection environment
Fecal Coliform or E. coli (In the year) 0 A routine sample and a 0 Human and animal fecal waste
0 routine sample detect
total coliform and either
sample also detects fecal
coliform or E. coli
_____________________________________________________________________________________________________________
(complete if bacteria detected) of Detections violation MCL MCLG Typical Source of Bacteria
Total Coliform Bacteria (In a mo.) 0 More than 1 sample in a 0 Naturally present in the
0 month with a detection environment
Fecal Coliform or E. coli (In the year) 0 A routine sample and a 0 Human and animal fecal waste
0 routine sample detect
total coliform and either
sample also detects fecal
coliform or E. coli
_____________________________________________________________________________________________________________
TABLE 2 – SAMPLING RESULTS SHOWING THE DETECTION OF LEAD AND COPPER
90th
Lead and Copper percentile No. sites
(complete if lead or copper Sample samples level exceeding
detected in the last sample set) Date collected detected AL AL PHG Typical Source of Contaminant
Lead (ppb) 2013 5 <4 0 15 0.2 Internal corrosion of household
water plumbing systems; discharge from industrial manufacturers; erosion of natural deposits
Copper (ppm) 2013 5 0.39 0 1.3 0.3 Internal corrosion of household
plumbing systems; erosion of
natural deposits; leaching from
wood preservatives
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Lead and Copper percentile No. sites
(complete if lead or copper Sample samples level exceeding
detected in the last sample set) Date collected detected AL AL PHG Typical Source of Contaminant
Lead (ppb) 2013 5 <4 0 15 0.2 Internal corrosion of household
water plumbing systems; discharge from industrial manufacturers; erosion of natural deposits
Copper (ppm) 2013 5 0.39 0 1.3 0.3 Internal corrosion of household
plumbing systems; erosion of
natural deposits; leaching from
wood preservatives
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TABLE 3 – SAMPLING RESULTS FOR SODIUM AND HARDNESS
Chemical or Constituent Sample Level Range of PHG
(and reporting units) Date Detected Detection MCL (MCLG) Typical Source of Contaminant
Sodium (ppm) 7/8/2014 280 270-290 none none Salt present in the water and is
generally naturally occurring
Hardness (ppm) 7/8/2014 259.5 247-272 none none Sum of polyvalent cations present
In the water, generally magnesium and calcium, and are usually naturally occurring
*Any violation of an MCL or AL is asterisked. Additional information regarding the violation is provided later in this report.
____________________________________________________________________________________________________________
(and reporting units) Date Detected Detection MCL (MCLG) Typical Source of Contaminant
Sodium (ppm) 7/8/2014 280 270-
generally naturally occurring
Hardness (ppm) 7/8/2014 259.5 247-
In the water, generally magnesium and calcium, and are usually naturally occurring
*Any violation of an MCL or AL is asterisked. Additional information regarding the violation is provided later in this report.
____________________________________________________________________________________________________________
TABLE 4 – DETECTION OF CONTAMINANTS WITH A PRIMARY DRINKING WATER STANDARD
PHG
Chemical or Constituent Sample Level Range of MCL (MCLG)
(and reporting units) Date Detected Detections (MRDL) [MRDLG] Typical Source of Contaminant
Aluminum 7/8/2014 0.155 <0.05-0.310 1 0.6 Erosion of natural deposits;
residue from some surface water
treatment process.
Arsenic, (ppb) 12/9/2014 7.60 <2-24 10 0.004 Erosion of natural deposits;
runoff from orchards; glass and
electronics production wastes.
Chromium (ppb) 7/8/2014 6.5 <10-13 50 (100) Discharge from steel and pulp
mills and chrome plating
erosion of natural deposits
Copper (ppm) 7/8/2014 0.036 <0.050-0.071 (AL=1.3) 0.3 Internal corrosion of household
plumbing systems; erosion of
natural deposits;
from wood preservatives
Fluoride (ppm) 7/8/2014 0.41 0.40-0.42 2.0 1 Erosion of natural deposits;
water additive which promotes
strong teeth; discharge from
fertilizer and aluminum factories.
Hexavalent Chromium 8/13/2014 8.45 4.8-11 10 0.02 Discharge from electroplating
VI (ppb) factories, leather tanneries,
wood preservation, chemical
synthesis, refractory production,
and textile manufacturing
facilities; erosion of natural
deposits.
Nitrate (as NO3) (ppm) 7/8/2014 6.33 <2.0-13.3 45 45 Runoff and leaching from
fertilizer use; leaching from
septic tanks and sewage;
erosion of natural deposit.
Selenium (ppb) 7/8/2014 4.5 <5.0-9.0 50 30 Discharge from petroleum,
glass, and metal refineries;
erosion of natural deposits;
discharge from mines and
chemical manufacturers; runoff
from livestock lots (feed
additive).
Gross Alpha Particle 9/5/2014 2.65 2.59-2.70 15 (0) Erosion of natural deposits
Activity (pCi/L)
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Chemical or Constituent Sample Level Range of MCL (MCLG)
(and reporting units) Date Detected Detections (MRDL) [MRDLG] Typical Source of Contaminant
Aluminum 7/8/2014 0.155 <0.05-
residue from some surface water
treatment process.
Arsenic, (ppb) 12/9/2014 7.60 <2-
runoff from orchards; glass and
electronics production wastes.
Chromium (ppb) 7/8/2014 6.5 <10-
mills and chrome plating
erosion of natural deposits
Copper (ppm) 7/8/2014 0.036 <0.050-
plumbing systems; erosion of
natural deposits;
from wood preservatives
Fluoride (ppm) 7/8/2014 0.41 0.40-
water additive which promotes
strong teeth; discharge from
fertilizer and aluminum factories.
Hexavalent Chromium 8/13/2014 8.45 4.8-
VI (ppb) factories, leather tanneries,
wood preservation, chemical
synthesis, refractory production,
and textile manufacturing
facilities; erosion of natural
deposits.
Nitrate (as NO3) (ppm) 7/8/2014 6.33 <2.0-
fertilizer use; leaching from
septic tanks and sewage;
erosion of natural deposit.
Selenium (ppb) 7/8/2014 4.5 <5.0-
glass, and metal refineries;
erosion of natural deposits;
discharge from mines and
chemical manufacturers; runoff
from livestock lots (feed
additive).
Gross Alpha Particle 9/5/2014 2.65 2.59-
Activity (pCi/L)
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TABLE 5 – DETECTION OF CONTAMINANTS WITH A SECONDARY DRINKING WATER STANDARD
Chemical or Constituent Sample Level Range of PHG
(and reporting units) Date Detected Detections MCL (MCLG) Typical Source of Contaminant
Turbidity (Units) 7/8/2014 2.5 <0.10-
Chloride (ppm) 7/8/2014 275 270-
deposits; seawater influence
Iron, sources (ppb) 10/6/2014 702.22* <100-
industrial wastes
Manganese (ppb) 10/6/2014 15.33 <20-
Sulfate (ppm) 7/8/2014 160 150-
deposits; industrial wastes
Total Dissolved Solids 7/8/2014 1,100* 1,100-
(TDS), (ppm) deposits
Zinc (ppm) 7/8/2014 0.340 <0.050-
deposits; industrial wastes
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TABLE 6 – DETECTION OF UNREGULATED CONTAMINANTS
Chemical or Constituent Sample Level Range of
(and reporting units) Date Detected Detections Notification Level Health Effects Language
*Any violation of an MCL, MRDL, or TT is asterisked. Additional information regarding the violation is provided later in this report.
(and reporting units) Date Detected Detections Notification Level Health Effects Language
*Any violation of an MCL, MRDL, or TT is asterisked. Additional information regarding the violation is provided later in this report.
Additional General Information on Drinking Water
Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that the water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the USEPA’s Safe Drinking Water Hotline (1-800-426-4791).
Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organtransplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at riskfrom infections. These people should seek advice about drinking water from their health care providers. USEPA/Centersfor Disease Control (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (1-800-426-4791).
Lead-Specific Language for Community Water Systems: If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. (INSERT NAME OF UTILITY) is responsible for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline or at http://www.epa.gov/safewater/lead.
Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-
Lead-
Summary Information for Violation of a MCL, MRDL, AL, TT,
or Monitoring and Reporting Requirement
VIOLATION OF A MCL, MRDL, AL, TT, OR MONITORING AND REPORTING REQUIREMENT
or Monitoring and Reporting Requirement
VIOLATION OF A MCL, MRDL, AL, TT, OR MONITORING AND REPORTING REQUIREMENT
Actions Taken to Correct Health Effects
Violation Explanation Duration the violations Language
*Iron Quarterly well Since 1995 Greensand filter None
monitoring
*Total Dissolved High levels in July, July 2014 Not available None
Solids 2014
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For Water Systems Providing Ground Water as a Source of Drinking Water
Table 7 – Sampling Results Showing
Fecal Indicator-Positive Ground Water Source Samples
Fecal Indicator-
Microbiological Contaminants Total No. of Sample MCL PHG
(complete if fecal-
(MRDLG)
Enterococci (In the year) TT n/a Human and animal fecal waste
Coliphage (In the year) TT n/a Human and animal fecal waste
_____________________________________________________________________________________________________________
Summary Information for Fecal Indicator-Positive Ground Water Source Samples,
Uncorrected Significant Deficiencies, or Ground Water TT
Uncorrected Significant Deficiencies, or Ground Water TT
__________________________________________________________________________________________________________
SPECIAL NOTICE OF FECAL INDICATOR-
__________________________________________________________________________________________________________
SPECIAL NOTICE FOR UNCORRECTED SIGNIFICANT DEFICIENCIES
__________________________________________________________________________________________________________
VIOLATION OF GROUND WATER TT
TT Violation Explanation Duration Actions Taken to Correct Health Effects
The violation Language
For Systems Providing Surface Water as a Source of Drinking Water
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TABLE 8 -
Treatment Technique (a)
(Type of approved filtration technology used) Turbidity of the filtered water must:
Turbidity Performance Standards (b) 1 – Be less than or equal to _____ NTU in 95% of measurements in a month.
(that must be met through the water treatment process) 2 – Not exceed _____ NTU for more than eight consecutive hours.
3 – Not exceed ____ NTU at any time.
Lowest monthly percentage of samples that met Turbidity
Performance Standard No. 1.
Highest single turbidity measurement during the year
Number of violations of any surface water treatment
requirements
(a) A required process intended to reduce the level of a contaminant in drinking water.
(b) Turbidity (measured in NTU) is a measurement of the cloudiness of water and is a good indicator of water quality and filtration performance.
Turbidity results which meet performance standards are considered to be in compliance with filtration requirements.
* Any violation of a TT is marked with an asterisk. Additional information regarding the violation is provided below.
_____________________________________________________________________________________________________________
Summary Information for Violation of a Surface Water TT
VIOLATION OF A SURFACE WATER TT
VIOLATION OF A SURFACE WATER TT
TT Violation Explanation Duration Actions Taken to Correct Health Effects
the Violation Language
the Violation Language
Summary Information for Operating Under a Variance or Exemption
Drinking Water Source Assessment
Water System
BEST ROAD MWC
San Benito County
Water Source
WELL 01
Assessment Date
August, 2002
Assessment Completed By
CDPH Monterey District
__________________________________________________________________
California Department of Public Health
Drinking Water Field Operations Branch
CDPH Monterey District
District No. 05
System No. 3500823
Source No. 002
PS Code 3500823-
Vulnerability Summary
District Name: CDPH Monterey District District No. 05 County: San Benito
System Name: BEST ROAD MWC System No: 3500823
Source Name: WELL 01 Source No: 002 PS CODE: 3500823-
Completed by: CDPH Monterey District Date: August, 2002
According to CDPH records, this Source is Groundwater. This Assessment was done using the Default Groundwater System Method.
A source water assessment was conducted for the WELL 01 of the BEST ROAD MWC water system in August, 2002
The source is considered most vulnerable to the following activities associated with contaminants detected in the water supply:
Septic systems -
The source is considered most vulnerable to the following activities not associated with any detected contaminants:
Crops, nonirrigated [e.g., Christmas trees, grains, grass seeds, hay,
Transportation corridors -
Storm Water Detention Facilities
Discussion of Vulnerability
Well 01 is considered most vulnerable to low density septic systems. This activity is associated with the contaminant nitrate, which has been detected in the water supply. The well is also considered vulnerable to the following activity not associated with any detected contaminants: storm water detention facilities.
Although outside of the 10 year zone of influence, there is a landfill located approximately 1 mile from the wells. This landfill could have long term effects on water quality in the area.
A copy of the complete assessment may be viewed at:
Best Road MWC
P.O. Box 395
Hollister, CA 95024
You may request a summary of the assessment be sent to you by contacting:
Gary Solmonson
President
(831) 634-
garwsol@hotmail.com
Vulnerability Ranking
District Name: CDPH Monterey District District No. 05 County: San Benito
System Name: BEST ROAD MWC System No: 3500823
Source Name: WELL 01 Source No: 002 PS CODE: 3500823-
Completed by: CDPH Monterey District Date: August, 2002
The following PCAs were identified in the assessment and are listed in priority order based on risk to the water supply. Refer to the last page for more information.
PCA Risk Zone PBE Vulnerability
Zone PCA (Risk Ranking) * Points Points Points Score
B5 Septic systems-
B10 Septic systems-
A Crops, nonirrigated [e.g., Christmas trees, grains, grass seeds, hay, 1 5 3 9
pasture] [includes drip-
A Transportation corridors -
B5 Storm Water Detention Facilities (M) 3 3 3 9
Explanation of Source Water Assessments and Definition of Terms
A source water assessment was recently completed for this drinking water source. The assessment identifies the vulnerability of the drinking water supply to contamination from typical human activities. The assessments are intended to facilitate and provide the basic information necessary for a local community to develop a program to protect the drinking water supply.
A summary of the complete assessment is provided here. For more information, contact the agency or individual that prepared the assessment (shown in summary). You may also contact the local Department of Public Health Drinking Water Field Operations Branch district office (http://www.cdph.ca.gov/programs/Documents/DDWEM/OriginalDistrictMapCDPH.pdf).
Additional information about assessments can be found at: http://www.cdph.ca.gov/certlic/drinkingwater/Pages/DWSAP.aspx
Terms used in this summary:
Source Water Assessment: An assessment is an evaluation of a drinking water source to determine the "possible contaminating activities" (PCAs) to which the source is most vulnerable. The assessment includes: a delineation of protection zones around the source; an inventory of the types of PCAs within the source protection zones; and an analysis to determine the PCAs to which the source is most vulnerable. The information is compiled into a report that includes a map, calculations, checklists, and a summary of the findings.
Possible Contaminating Activity (PCA): A PCA is a current or historic human activity that is an actual or potential origin of contamination for a drinking water source. PCAs include activities that use, store, produce or dispose of chemicals that have the potential to contaminate drinking water supplies. There are 110 types of PCAs in the California DWSAP program.
PCA Risk Ranking: Each type of PCA is assigned a risk ranking (Very High, High, Moderate, or Low). The risk ranking is based on the contaminant(s) typically associated with that PCA, the likelihood of release from that type of facility based on historical experience, and the mobility of the contaminant(s).
PCA Inventory: The PCA inventory is a review using local knowledge, databases, and on-
Source Water Zones or Areas: These are areas located around and typically adjacent to a drinking water source that have been identified as initial protection areas.
For groundwater sources, there are typically three concentric circular zones around a source (Zones A, B5 and B10). The sizes of the are determined based on characteristics of the source. PCAs located in the inner Zone A are considered more of a risk to the water supply than PCAs located in the middle Zone B5. Similarly, PCAs located in Zone B5 are considered more of a risk than PCAs located in the outer Zone B10.
For surface water sources, the watershed is defined as the overall protection area, and as an option, zones are defined closer to the source. Two types of zones are typically established. Zone A is the area within and near the surface water body and its tributaries. Zone B is an area within 2,500 feet of the intake, not including areas in Zone A. For surface water sources, PCAs located in Zone A are considered a greater threat than PCAs located in Zone B. PCAs located on the watershed outside of the zones are considered to be of less risk to the water supply. If zones have not been defined, PCAs are considered to be of equal risk regardless of location on the watershed.
Physical Barrier Effectiveness (PBE): The PBE for a source is an evaluation of the ability of the source and the surrounding area to prevent the movement of contaminants into the source. The PBE is based on the construction and operation features of the source, and the characteristics of the surrounding area. A source is assigned a PBE of Low, Moderate or High, where High indicates that the physical barriers of the source and site are very effective in preventing the movement of contaminants. By design, typical groundwater sources will have Moderate PBE, while typical surface water sources will have Low PBE. This is due to the greater exposure of surface water sources to contamination.
Vulnerability Ranking: The vulnerability ranking is a summary of the PCAs identified in the assessment prioritized by the risk that they pose to the water supply. The prioritization is based on the risk associated with a PCA, the zone in which it occurs, and the PBE of the source. In the vulnerability ranking, points are assigned as follows:
PCA risk ranking Very High = 7 High = 5 Moderate = 3 Low = 1 Unknown in any zone = 0
Zone (Groundwater) A =5 B5 = 3 B10 = 1
Zone (Surface water with zones) A = 5 B = 3 Watershed = 1
Zone (Surface water without zones) Watershed = 5
Physical Barrier Effectiveness Low = 5 Moderate = 3 High = 1
The points for each type of PCA in each zone are totaled to give a vulnerability score, and the PCAs are ranked in order from the highest score to the lowest score. PCAs associated with detected contaminants are ranked at the top, regardless of vulnerability score. By definition, groundwater sources are not considered vulnerable to PCAs with scores less than 8, and surface water sources are not considered vulnerable to PCAs with scores less than 11. It should be noted that the vulnerability ranking scores do not have a direct quantitative value. Rather, the points are used only to relatively rank the types of PCAs for an individual source.
Note: Some of the summaries do not include a vulnerability ranking. If the assessment was done on paper and the details were not entered into the database, the vulnerability ranking is not available here. In addition, alternate methods of determining vulnerability were allowed in some cases, and the vulnerability ranking is not in the database.
Vulnerability Summary: The source is considered most vulnerable to the PCAs with the highest score, and to PCAs associated with detected contaminants. These PCAs are noted in the vulnerability summary. Further details or discussion may be provided in the vulnerability discussion.
Drinking Water Source Assessment
Water System
BEST ROAD MWC
San Benito County
Water Source
WELL 02
Assessment Date
August, 2002
Assessment Completed By
CDPH Monterey District
__________________________________________________________________
California Department of Public Health
Drinking Water Field Operations Branch
CDPH Monterey District
District No. 05
System No. 3500823
Source No. 003
PS Code 3500823-
Vulnerability Summary
District Name: CDPH Monterey District District No: 05 County: San Benito
System Name: BEST ROAD MWC System No: 3500823
Source Name: WELL 02 Source No: 003 PS CODE: 3500823-
Completed by: CDPH Monterey District Date: August, 2002
According to CDPH records, this Source is Groundwater. This Assessment was done using the Default Groundwater System Method.
A source water assessment was conducted for the WELL 02 of the BEST ROAD MWC water system in August, 2002
.
The source is considered most vulnerable to the following activities not associated with any detected contaminants:
Storm Water Detention Facilities
Discussion of Vulnerability
Although outside of the 10 year zone of influence, there is a landfill located 1 mile from the wells. This landfill could have long term effects on water quality in the area.
A copy of the complete assessment may be viewed at:
Best Road MWC
P.O. Box 395
Hollister, CA 95024
You may request a summary of the assessment be sent to you by contacting:
Gary Solmonson
President
(831) 634-
garwsol@hotmail.com
Vulnerability Ranking
PCA Risk Zone PBE Vulnerability
Zone PCA (Risk Ranking) * Points Points Points Score
A Storm Water Detention Facilities (M) 3 5 3 11
A Crops, nonirrigated [e.g., Christmas trees, grains, grass seeds, hay, 1 5 3 9
pasture] [includes drip-
A Transportation corridors-
Explanation of Source Water Assessments and Definition of Terms
A source water assessment was recently completed for this drinking water source. The assessment identifies the vulnerability of the drinking water supply to contamination from typical human activities. The assessments are intended to facilitate and provide the basic information necessary for a local community to develop a program to protect the drinking water supply.
A summary of the complete assessment is provided here. For more information, contact the agency or individual that prepared the assessment (shown in summary). You may also contact the local Department of Public Health Drinking Water Field Operations Branch district office (http://www.cdph.ca.gov/programs/Documents/DDWEM/OriginalDistrictMapCDPH.pdf).
Additional information about assessments can be found at: http://www.cdph.ca.gov/certlic/drinkingwater/Pages/DWSAP.aspx
Terms used in this summary:
Source Water Assessment: An assessment is an evaluation of a drinking water source to determine the "possible contaminating activities" (PCAs) to which the source is most vulnerable. The assessment includes: a delineation of protection zones around the source; an inventory of the types of PCAs within the source protection zones; and an analysis to determine the PCAs to which the source is most vulnerable. The information is compiled into a report that includes a map, calculations, checklists, and a summary of the findings.
Possible Contaminating Activity (PCA): A PCA is a current or historic human activity that is an actual or potential origin of contamination for a drinking water source. PCAs include activities that use, store, produce or dispose of chemicals that have the potential to contaminate drinking water supplies. There are 110 types of PCAs in the California DWSAP program.
PCA Risk Ranking: Each type of PCA is assigned a risk ranking (Very High, High, Moderate, or Low). The risk ranking is based on the contaminant(s) typically associated with that PCA, the likelihood of release from that type of facility based on historical experience, and the mobility of the contaminant(s).
PCA Inventory: The PCA inventory is a review using local knowledge, databases, and on-
Source Water Zones or Areas: These are areas located around and typically adjacent to a drinking water source that have been identified as initial protection areas.
For groundwater sources, there are typically three concentric circular zones around a source (Zones A, B5 and B10). The sizes of the are determined based on characteristics of the source. PCAs located in the inner Zone A are considered more of a risk to the water supply than PCAs located in the middle Zone B5. Similarly, PCAs located in Zone B5 are considered more of a risk than PCAs located in the outer Zone B10.
For surface water sources, the watershed is defined as the overall protection area, and as an option, zones are defined closer to the source. Two types of zones are typically established. Zone A is the area within and near the surface water body and its tributaries. Zone B is an area within 2,500 feet of the intake, not including areas in Zone A. For surface water sources, PCAs located in Zone A are considered a greater threat than PCAs located in Zone B. PCAs located on the watershed outside of the zones are considered to be of less risk to the water supply. If zones have not been defined, PCAs are considered to be of equal risk regardless of location on the watershed.
Physical Barrier Effectiveness (PBE): The PBE for a source is an evaluation of the ability of the source and the surrounding area to prevent the movement of contaminants into the source. The PBE is based on the construction and operation features of the source, and the characteristics of the surrounding area. A source is assigned a PBE of Low, Moderate or High, where High indicates that the physical barriers of the source and site are very effective in preventing the movement of contaminants. By design, typical groundwater sources will have Moderate PBE, while typical surface water sources will have Low PBE. This is due to the greater exposure of surface water sources to contamination.
Vulnerability Ranking: The vulnerability ranking is a summary of the PCAs identified in the assessment prioritized by the risk that they pose to the water supply. The prioritization is based on the risk associated with a PCA, the zone in which it occurs, and the PBE of the source. In the vulnerability ranking, points are assigned as follows:
PCA risk ranking Very High = 7 High = 5 Moderate = 3 Low = 1 Unknown in any zone = 0
Zone (Groundwater) A =5 B5 = 3 B10 = 1
Zone (Surface water with zones) A = 5 B = 3 Watershed = 1
Zone (Surface water without zones) Watershed = 5
Physical Barrier Effectiveness Low = 5 Moderate = 3 High = 1
The points for each type of PCA in each zone are totaled to give a vulnerability score, and the PCAs are ranked in order from the highest score to the lowest score. PCAs associated with detected contaminants are ranked at the top, regardless of vulnerability score. By definition, groundwater sources are not considered vulnerable to PCAs with scores less than 8, and surface water sources are not considered vulnerable to PCAs with scores less than 11. It should be noted that the vulnerability ranking scores do not have a direct quantitative value. Rather, the points are used only to relatively rank the types of PCAs for an individual source.
Note: Some of the summaries do not include a vulnerability ranking. If the assessment was done on paper and the details were not entered into the database, the vulnerability ranking is not available here. In addition, alternate methods of determining vulnerability were allowed in some cases, and the vulnerability ranking is not in the database.
Vulnerability Summary: The source is considered most vulnerable to the PCAs with the highest score, and to PCAs associated with detected contaminants. These PCAs are noted in the vulnerability summary. Further details or discussion may be provided in the vulnerability discussion.