H 2O REPORT
H2O Report is an annual publication of Beaver Water District
Summer 2010
We are pleased to provide you with this
annual report on the quality of your drinking water.
Beaver Water District sells water to Fayetteville,
Springdale, Rogers and Bentonville. These cities in
turn sell the water to retail customers, as well as
wholesaling water to smaller communities. Inside
this report are some of the most critical water
quality data, as well as data frequently requested by end users. Additionally, we have included useful definitions related to common water quality parameters.
Once again in 2009, the District achieved 100% compliance with state and federal
drinking water regulations. While Beaver Lake's raw water quality varies throughout the
year, the drinking water that is pumped to your home must be of consistent quality at all
times. The conventional treatment processes utilized by the District - which include filtration and chlorine disinfection -- are quite effective in treating water from Beaver Lake. Our
staff is well trained and committed to insuring that the drinking water we produce is exceptional and is safe for you to drink.
All of us, including you, have a part to play in seeing to it that Beaver Lake remains a
high quality source of water for our region. Failure to do so could easily result in much more
sophisticated and expensive treatment, which means drinking water might cost you more
money at the tap. Did you know that one in eight Arkansans receives drinking water from
Beaver Lake? The lake is a valuable resource for our region, both for quality of life and
health, as well as for the economic well-being of Northwest Arkansas. We urge you to consume, conserve and connect with Beaver Water District and Beaver Lake. Visit
www.bwdh2o.org and click the water faucet logo to learn more about what you can do to
help. Help us to help you connect today's actions with tomorrow's planet. For more detailed
water quality data, visit the website and download the detailed 2009 Water Quality Report.
If you have questions, please e-mail [email protected] or call 479-756-3651.
Misssio
on
Our mission is to serve our customers in the Benton and Washington County
area by providing high quality drinking water that meets or exceeds all federal
and state regulatory requirements in such quantities as meets their demands
and is economically priced consistent with our quality standards.
Page 2
pH
pH is the measurement of how acidic or basic the water is. The pH scale is from 0 to 14. A pH of less than
7.0 means the water is acidic while a pH of greater than 7.0 is basic. A pH of 7.0 is considered neutral.
Hardness and Alkalinity
Hardness in water is caused by the presence of calcium and magnesium ions. Hard water can cause an
increase in soap and detergent usage and increase mineral deposits (scaling) in hot water tanks and plumbing systems. The light colored ring that forms in a pan after boiling water is a result of the hardness of the water. Soft
water doesn’t require as much soap to work up a lather; however, if the water is too soft you will have trouble rinsing the soap off and may be left with a slimy feeling. The 2009 average hardness of the water distributed by Beaver
Water District was 70 parts per million (ppm) which is moderately hard according to the table below.
Water Hardness Scale
Grains Per Gallon
less than 1.0
1.0 - 3.5
3.5 - 7.0
7.0 - 10.5
over 10.5
Parts Per Million (ppm)
less than 17.1
17.1 – 60
60 – 120
120 – 180
over 180
Classification
Soft
Slightly Hard
Moderately Hard
Hard
Very Hard
Alkalinity is the quantitative capacity of water to neutralize an acid; that is, the measure of how much acid
can be added to a liquid without causing a significant pH change. Automatic dishwasher detergents, most
cleansers and hard surface cleaners utilize alkalinity for their cleaning ability. Hardness and alkalinity are often
talked about together because many chemical substances contribute to both hardness and alkalinity.
Coliform
Coliforms are a group of non-pathogenic bacteria that are naturally present in the environment as well as in
feces. Total Coliforms are not a health threat in itself but are used to indicate if other potentially harmful bacteria
may be present.
Turbidity
Soil runoff is one of the main sources of turbidity. Turbidity is a measure of the cloudiness of water. It is
used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present).
Higher turbidity levels are often associated with higher levels of disease- causing microorganisms such as viruses, parasites, and some bacteria.
Trihalomethanes and Haloacetic Acids
Disinfection byproducts are compounds that are formed when disinfectants like chlorine combine with
organic matter in the water. Trihalomethanes (THMs) and Haloacetic Acids (HAA5) are two classes of these
byproducts that are regulated because of potential negative health effects and have limits established by the
Environmental Protection Agency (EPA) of 80 ppb and 60 ppb respectively.
Total Organic Carbon (TOC)
Total Organic Carbon (TOC) is a measure of the organic content in the water. Since the disinfection byproducts
(DBP) listed above are formed from the combination of chlorine and organic matter, TOC is used as a “precursor”
for DBP formation. TOC samples can be analyzed more quickly and are less costly to run than THM and HAAs.
Cryptosporidium and Giardia
Cryptosporidium and Giardia are microscopic parasites that are resistant to chlorine disinfection. They cause
gastrointestinal illness including nausea, vomiting, and diarrhea. Cases are most prevalent in younger children in
daycare facilities, workers or parents caring for infected children, hikers who drink unfiltered water, and international travelers. These microorganisms can be transmitted through ingestion of infected water; recreational waters
like fountains and water parks are common sources of outbreaks.
Page 3
2009 Water Quality Results
* For the full Water Quality Report, go to
www.bwdh2o.org
PRIMARY STANDARDS - Health Related and Mandated by U.S. EPA & ADH
Disinfectant
Units
MCLG
MCL
BWD
Total Residual Chlorine*
Range of Results
Clarity
Turbidity * (Finished Water)
Highest yearly sample result
Average NTU
Lowest % of samples meeting
Microbiological
Total Coliform Bacteria
Fecal Coliform or Escherichia coli
Inorganic Chemicals
Fluoride (Average)
Range of Results
ppm
ppm
Units
4.0
4.0
MCLG
n/a
MCL
>0.3 NTU in
>5% of samples
or any 1
sample>1 NTU
1.47
1.30-1.75
BWD
MCLG
0
0
MCLG
4.0
MCL
1/month
0
MCL
4.0
Units
MCLG
MCL
BWD
ppb
N/A
80
65.6
32-108
ppb
N/A
60
48.2
20-68
Volatile Organic Contaminants (VOC’s) Regulated
Total Trihalomethanes (TTHMs)
Highest Running Annual
Range of quarterly samples
Haloacetic Acids 5 (HAA5)
Highest Running Annual
Range of quarterly samples
NTU
NTU
%
Units
P/A
P/A
Units
ppm
ppm
0.14
0.10
100
BWD
0
0
BWD
0.93
0.78-1.04
SECONDARY STANDARDS - Aesthetic Standards Recommended by EPA & ADH
Physical Parameters
Apparent Color
pH * (Average)
Inorganic Chemicals
Chloride
Units
units
units
Units
ppm
MCLG
15
6.5 - 8.5
MCLG
250
BWD
0
8.3
BWD
9
UNREGULATED CONSTITUENTS - Monitored by ADH and BWD *
Physical and Chemical Parameters
Alkalinity (Total) *
Conductivity *
Hardness (Total) *
Range of Results
Sodium
Units
BWD
ppm as CaCO33 47 (avg)
186 (avg)
µ S/cm
ppm as CaCO33 70 (avg)
ppm as CaCO33 54-92
ppm
7.82
Page 4
State of the Lake, 2009
By Robert Morgan, Ph.D.,
Manager of Environmental Quality
Weather wise, 2009 was exciting in Northwest
Arkansas. We started the year with a record-breaking
ice storm in January, had a cool and somewhat wet
spring, ample rain that continued through the summer,
and a cooler than normal fall. However, water quality
wise, 2009 was fairly boring for Beaver Lake. And that
is the way we at Beaver Water District like it! Boring is
good when it comes to water quality in Beaver Lake.
The surface elevation of the lake started the year
right at the top of the conservation pool at 1120.39 feet
above mean sea level. On Dec. 31st, the surface was at
elevation 1127.66 for a net gain of 7.27 feet or 215,309
acre feet. During the year, the maximum surface elevation was 1129.24, just 0.76 feet below the top of the
flood pool, and the minimum was 1118.05. According
to the U.S. Army Corps of Engineers website, 1,425,845
acre feet were withdrawn from the lake during the year.
The vast majority of water withdrawn, 1,110,762 acre
feet, was for hydropower production, while 66,716 acre
feet were withdrawn for water supply, 74,450 acre feet
evaporated, and the rest went to seepage.
We were fortunate for the second year in a row in
not having a serious taste and odor event. Taste and
odor at Beaver Lake is usually caused by
2-Methylisoborneol or MIB for short. MIB is a byproduct of blue-green algae metabolism. Research at the
University of Arkansas -- one project conducted by Dr.
Sonja Hausmann and Byron Winston and another by Dr.
Thad Scott -- indicates that blue-green algae in the lake
become problematic when the nitrogen to phosphorus
ratio in the water drops below 30. It appears that the late
season rains that maintain inflow to the lake reduce the
chance of serious taste and odor events. Most years,
when rains end in July, nitrogen quickly dissipates from
the lake leaving a surplus of phosphorus relative to the
available nitrogen.
Turbidity in Beaver Lake at the Beaver Water
District intake near Hickory Creek averaged 12.9 NTUs
during 2009. (NTU stands for nephelometric turbidity
unit and it's a measure of the clarity of the water.) The
maximum turbidity occurred Oct. 9 following 6 ½
inches of rain in the watershed. The highest recorded
value was 242 NTUs. For several years, the average
turbidity in Beaver Lake has been improving, with the
exception of extreme turbidities after storm events.
Overall, 2009 was a very good year for Beaver
Lake. With everyone's help, we can keep it that way.
Beaver Lake
Water Use 2009
1,425,845 Acre Feet (AF)
Domesc Water 5%
(66,716 AF)
Evaporaon 6%
(74,450 AF)
Seepage 2%
(23,250 AF)
Hydropower 87%
(1,110,762 AF)