|
Cash Water Supply's 2007 Monitoring
Results
for
Contaminants in Drinking Water
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You
may be more vulnerable than the general population
to certain microbial contaminants, such as
Cryptosporidium, in drinking water. Infants,
some elderly, or Immuno-compromised persons
such as those undergoing chemotherapy for
cancer; those who have undergone organ transplants;
those who are undergoing treatment with steroids;
and people with HIV/AIDS or other immune
system disorders can be particularly at risk
from infections. You should seek advice about
drinking water from your physician or health
care provider. Additional guidelines on appropriate
means to lessen the risk of infection by
Crytosporidium are available from the Safe
Drinking Water Hotline (1-800-426-4791).
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 water poses
a health risk. More information about contaminants
and potential health effects can be obtained
by calling the EPA's Safe Drinking Water Hotline
(1-800-426-4791).
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.
In
order to ensure that tap water is safe to
drink, EPA prescribes regulations which limit
the amount of certain contaminants in water
provided by public water systems. Food and
Drug Administration regulations establish
limits for contaminants in bottled water,
which must provide the same protection for
public health.
Definitions:
Maximum Contaminant Level (MCL):
The highest level of a contaminant that is allowed
in drinking water. MCLs are set as close to
the MCLGs as feasible using the best available
treatment technology.
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 allow for a margin of safety.
Maximum Residual Disinfectant Level Goal (MRDLG):
The level of a drinking water disinfectant 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.
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.
Action Level (or AL): The concentration
of a contaminant, which, if exceeded, triggers
treatment or other requirements, which a water
system must follow.
Treatment Technique
(or TT): A required process intended
to reduce the level of a contaminant in drinking
water.
90th Percentile:
90% of samples are equal to or less than the
number in the chart.
NTU or Nephelometric Turbidity Units:
A measure of clarity.
NA: Not applicable.
ND: Not detectable at testing
limits.
Su: Standard Unit
PPB or parts per billion: micrograms
per liter (ug/l).
PPM or parts per million: milligrams
per liter (mg/l).
HARA: Highest Annual Rolling
Average.
CDC: Highest Annual Rolling
Average.
EPA: Environmenal Protection Agency.
IDSE (Initial Distribution System Evaluation):
An important part of the Stage 2 Disinfection
Byproducts Rule (DBPR) The IDSE is a one-time
study conducted by water systems to identify
distribution systems locations with high concentrations
of trihalomethanes (THMs) and haloacetic acids
(HAAs). Water systems will use results from
the IDSE, in conjunction with their Stage 1
DBPR compliance monitoring data, to select
compliance monitoring locations for the Stage
2 DBPR.
Contaminant |
Unit |
MCLG
Health Goal |
MCL
EPA's Limits |
Level
Detected |
Potential
Source of Contamination |
Cash
Water |
NTMWD |
Microbiological
Contaminants |
| Total
Coliform Bacteria |
pos/neg |
0 |
One
Positive Monthly Sample |
One
Positive in October 2007 |
NA |
Naturally
present in the environment |
| Total
Organic Carbon |
ppm
|
NA
|
TT
|
10.7*
|
|
Naturally
present in the environment |
4.84
- 10.7
|
2.82
- 4.16
|
*measured
in ppm in the source water |
**measured
in ppm in the finished water
|
| Turbidity2 |
NTU
|
NA
|
TT/never
more than 1 NTU and less than 0.3 NTU
in 95% of samples
|
0.17
(average)
|
0.14
(average)
|
Soil
Runoff. |
| 0.29
(highest) |
0.03-0.56
(range) |
100%
met limits
|
99.9%
met limits
|
Inorganic
Contaminants |
| Barium |
ppm
|
2
|
2
|
0.045
(2002)1
|
0.06
|
Discharge
of drilling wastes; Discharge from
metal refineries; Erosion of natural
deposits.
|
| Chlorite5 |
ppm
|
0.8
|
1
|
NA
|
0.66
(average)
ND - 1.41
|
By-product
of
drinking water
chlorination
|
| Chlorine
Dioxide |
ppb
|
MRDLG
= 800
|
MRDL
= 800
|
NA
|
|
Water
additive used to control microbes
|
| Copper |
ppm
|
1.3
|
1.3=
AL
|
0.135
(90th percentile)
|
|
Household
plumbing corrosion; Natural erosion;
Leaching from wood preservatives.
|
All
sites below AL
|
| Fluoride |
ppm
|
4
|
4
|
1.0
0.16 - 1.0
|
0.73
0.65
- 0.73
|
Natural erosion;
Water additive for strong teeth; Fertilizer & aluminum
factories discharge
|
| Lead |
ppb
|
0
|
15=
AL
|
1.3
(90th percentile)
|
NA
|
Corrosion
of household plumbing systems, Erosion
of natural deposits.
|
All
sites below AL
|
| Nitrate |
ppm
|
10
|
10
|
0.26
|
1.07
|
Fertilizer
runoff; Septic tank & sewage leaching;
Natural erosion |
0.96
- 1.07
|
| Synthetic
Organic Contaminants |
| Atrazine |
ppb
|
3
|
3
|
ND
|
0.4
|
Runoff
from herbicide used on row crops. |
| Volatile
Organic Contaminants and Disinfection
By-Products |
| Chloramines |
ppm
|
MRDLG
= 4
|
MRDL
= 4
|
2.17
HARA
|
2.5
(average)
|
Water
additive used to control microbes
|
1.8
- 2.5
|
0.6
- 3.9
|
Haloacetic
Acids (HAA5)
|
ppb
|
NA
|
60
|
41.4
HARA
|
21.2
HARA
|
Byproduct
of drinking water chlorination.
|
15.8
- 106.9
|
8.1
- 29.0
|
Total
Trihalo-
methanes3&6
(TTHMs) |
ppb
|
0
|
80
|
67.0
HARA
|
61.2
HARA
|
Byproduct
of drinking water chlorination.
|
29.4
- 155.9
|
33.9
- 66.8
|