 Tastes Great... And It's Safe
2002 Tap Water Test Results
Regulated Substances
Several substances present in drinking water are regulated and have Maximum
Contaminant Levels (MCLs) set by the EPA.
They are: trihalomethanes, haloacetic
acids, thallium, nitrate (as nitrogen), fluoride, alpha emitters, and carbon
tetrachloride. The levels of these regulated substances found in the JWC
water supply in 2002 and the typical source of each contaminant are listed
in the
table below:
| Regulated Substance Detected By Monitoring |
Units Of Measure |
Highest Amount Allowed In Water By
EPA (MCL) |
Amount Found In Joint Water Commission
Water |
Range Detected |
Ideal Goal (MCLG) |
Typical Source Of Substance |
| Total Trihalomethanes (TTHM) |
ppb |
80 |
Crystal: 37.7
GV: 32.05
NH: 31.6 |
16.5-74.0
19.9-47.2
14.9-57.7 |
— |
Disinfection by-products |
| Haloacetic Acids (HAA5) |
ppb |
60 |
Crystal: 30.65
GV: 19.5
NH: 27.2 |
14.7-58.0
1.4-28.8
15.5-51.9 |
0 |
Disinfection by-product |
| Thallium (7/2/99) |
ppb |
2.0 |
1.0 |
— |
<0.5 |
Leaching from ore-processing sites; glass, electronic, and
drug factory discharge |
| Nitrate as Nitrogen |
ppm |
10 |
0.38 |
— |
<10 |
Runoff from fertilizer use; leaching from
septic tanks, sewage; erosion of natural deposits |
| Fluoride |
ppm |
4.0 |
1.06 |
0.98-1.1 |
<4.0 |
State-required additive; erosion of natural deposits; fertilizer,
aluminum factory discharge |
| Alpha Emitters (7/1/99) |
pCi/L |
15.4 |
0.4 |
— |
0 |
Erosion of natural deposits |
|
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Lead and Copper
Lead and copper are also regulated substances, but they are evaluated
using a regulatory level known as Action Limit (AL). If the concentration
of lead or copper in the water exceeds the action limit, there are
additional treatment or other requirements the water system must follow.
Lead and copper get into tap water due to corrosion of home plumbing
systems. In the JWC system, both Golden Valley and New Hope distribution
systems have been found to be in violation of the lead limit in 2002.
Infants and children who consume water that contains lead in excess of the
action level (15 parts per billion) could experience delays in their physical
or mental development. Children could show slight deficits in attention span
and learning abilities. Adults who drink this water over many years could develop
kidney problems or high blood pressure.
You can substantially reduce the amount of lead in your water by simply letting
the tap run for 30 seconds to 2 minutes before using the water for drinking
or cooking. The JWC is working with the MWW to reduce corrosion and is engaged
in ongoing public education to inform water customers about the lead issue.
| Substance
Detected By Monitoring At Customers' Home |
Units of Measure |
Action Level
(Al)
|
# Of Samples
Exceeding The Action Level |
90% Of Samples
Were Below This Level |
Typical Source
Of Substance |
| Crystal |
Golden Valley |
New Hope |
Crystal |
Golden Valley |
New Hope |
| Lead |
ppb |
15 |
1 out of 30 |
3 out of 60 |
8 out of 60 |
6.8 |
8.3 |
21.0* |
Plumbing corrosion, natural
deposits |
| Copper |
ppm |
1.3 |
0 out of
30 |
0 out of
60 |
0 out of 60 |
0.12 |
0.15 |
0.13 |
Plumbing corrosion,
natural deposits |
|
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Turbidity
The MWW monitors turbidity (or cloudiness) of water at the treatment
plant. Tubidity helps indicate the effectiveness of the filtration
system.
The EPA has three basic requirements related to turbidity:
- certain treatment processes must be used to reduce turbidity
- 95% of monthly water samples must be below 0.5 Nephelometric Turbidity Units, (NTU), and
- All samples must be less than 5 NTU
| Turbidity
Monitoring |
Units
of Measure |
Lowest % Of
Monthly Samples Meeting Limits |
Highest Single Measurement |
Typical Source Of
Substance |
| Turbidity |
NTU |
Too low to measure |
Soil runoff |
|
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Unregulated Substances
Many unregulated substances are also monitored. They are evaluated
using state standards known as health risk limits. The data from
this monitoring
is used to determine future drinking water regulations.
| Unregulated Substance Detected
By Monitoring |
Units of Measure |
Amount Found In Joint Water Commission
Water |
Range Detected |
Typical Source Of Substance |
| Sulfate (7/2/99) |
ppm |
25.0 |
— |
Erosion of natural deposits |
| Sodium (7/2/99) |
ppm |
8.3 |
— |
Erosion of natural deposits |
|
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