E
NV
4970
2010
A Study of Well Water
Quality in the Front Range
Keywords: groundwater, water quality, domestic wells, drinking water, Colorado
Abstract: The study of groundwater quality is imperative to protect homeowners from contaminated drinking water health hazards. In this study, we take seven random well water samples from throughout Colorado, and administer a variety of quantitative tests on each sample. We look at pH levels, turbidity, conductivity, and levels of nitrates, ammonium, calcium, and chloride. We identify high concentrations of these
components that may indicate the need for further testing. We also look for any correlation of the results to well depth.
Introduction
Well water is an important resource for the United States. Domestic well water supplies roughly 43 million Americans with drinking water (10). In Colorado,
groundwater accounts for 18% of water used, and 19 counties rely on groundwater for drinking (2). The Safe Drinking Water Act and state laws do not regulate water quality from these privately owned domestic wells (10). Therefore, it is imperative for
homeowners to be aware that water quality and well maintenance are responsibilities that fall on the homeowner. Contaminated well water can be a source of human health hazards. For example, high nitrogen levels can cause “blue baby syndrome”. In one case, a Westcliffe couple decided to have their well water tested after drinking it for
nearly 20 years. The results came back with alarmingly high levels of e.coli, coliform bacteria, and lead. The water was deemed unsafe for human consumption.
Hypothyroidism, autism, and ADHD have all been linked to lead toxicity (13). All three family members relying on the water were previously diagnosed with one of these afflictions. There are several point and non-point sources for groundwater
contamination, both anthropogenic and natural. Some contamination sources include agriculture, mining, livestock waste, faulty septic systems, and contact with naturally occurring minerals. Clean fresh water is an invaluable resource. It is imperative for homeowners who rely on groundwater for drinking and domestic purposes to test and monitor their water in order to assess and ensure proper treatment techniques for the safety of anyone drinking the water.
Literature Review
There are not too many studies published that test for general well water quality in private domestic wells. Most are government publications on drinking water quality regulations. One study we found tested irrigation water seepage on groundwater along the Rio Grande. The surface water and groundwater was tested. The results show that there are no significant differences in ammonium. Groundwater electrical conductivity is higher than surface waters. Surface DO is higher than groundwater. Nitrate is higher in groundwater when the ditch is off, and lower than surface waters when the ditch is
running. When the irrigation ditch is running, surface water pHs are higher than groundwater well sites. The conclusion of this study is that seepage from the irrigation ditch dilutes groundwater ion concentrations.
Another study we looked at tested water quality of surface waters on the lower basin of the Euphrates River, which helps feed dam lakes used for drinking sources in the area. The study tested for turbidity, total dissolved solids, suspended solids, BOD, hardness, alkalinity, calcium, magnesium, sodium, potassium, chloride, fluoride, and sulfate. Calcareous main rock is dominant in the soils, and a basaltic soil is common (Alp, 2010). The results designate the surface waters as soft-middle hard, slightly alkaline, with moderate total dissolved solids and low organic content (Alp, 2010). It was concluded that the tested surface waters are affected by dam lakes in the upper basin.
A third study we looked at tested domestic well all across the United States, roughly 18,000 wells. This study tested for nitrate levels, volatile organic compounds, pesticides, chloroform, arsenic, and uranium and radon. According to the figures, several wells in Colorado were tested for radon, uranium, and nitrate. These are probably the most common natural contaminants in this state. The results indicate, “Inorganic contaminants were detected in many of the wells and, generally,
majority of samples were still below MCLs). Arsenic was detected in ~52% of the wells and exceeded the MCL in ~11%. Arsenic exceeded the MCL more than uranium, any VOC, and any pesticide analyzed” (Focazio et al., 2006).
Objective
This study attempts to understand the well water quality of Colorado. The study will attempt to identify any potential drinking water hazards. Well water quality is important because of possible health hazards that people may face when using well water for domestic purposes. It is important to identify the quality of these waters in order to utilize the correct filtration system to ensure the water is safe for human consumption. Water is a precious resource and we need to be aware of groundwater quality and how much is available for consumption.
Study Area
Our study area is broken down into seven specific well site locations in the Front Range. The span is from the northeast portion down to the southwest portion. There is a 1234 m difference from the highest site elevation to the lowest site elevation. Two well sites supply groundwater from rock fissures, two sites are charged by tributary
Ogallala Aquifers. The range in well depth from deepest to shallowest is 436.9 m. The two farthest sites from north to south are approximately 362 km apart.
Table 1 – Sample Site Information
Site Approximate
Elevation (meters)
Well Depth (meters)
Groundwater Source Coal Creek Canyon 2438 91.4 unnamed aquifer
Tarryall 2656 183 groundwater
Buckley A.F.B. 1726 440 Ogallala Aquifer
Deer Trail 1580 177 Denver Aquifer
Greeley 1422 3.1 tributary
Golden 1732 9.1 tributary
Methods
We randomly selected 7 well sites for our study. We asked friends and family for access to well water, and one sample we just drove to a house in Greeley with a well and asked for a sample. The seven sample sites are:
Site 1 – Coal Creek Canyon (CCC)
Site 2 – Tarryall
Site 3 – Buckley Air Force Base (AFB)
Site 4 – Deer Trail
Site 5 – Greeley
Site 6 – Golden
Site 7 – Cotopaxi
For our sample collection containers we used what was available to us. We used sterile collection jars for sites 1, 3, and 4. For site 2 we used glass jars rinsed with distilled water. For the rest of the sites we used empty plastic water bottles that we rinsed with distilled water prior to filling. We ran the raw water from the well for 2 minutes before collection. We refrigerated the samples until all testing was complete.
We used Vernier LabQuest ion-selective electrodes, probes, and sensors for testing. We obtained this equipment through the Metropolitan State College of Denver’s environmental science lab. The following is a list of the equipment used:
ammonium ion-selective electrode
calcium ion-selective electrode
chloride ion-selective electrode
conductivity probe
dissolved oxygen probe
nitrate ion-selective electrode
pH sensor
turbidity sensor
We rinsed testing containers, probes, and sensors with de-ionized or distilled water between each test. We calibrated each piece of equipment according to instructions in the manuals prior to beginning any test. We performed most tests twice and recorded the average of the reading for more accurate results.
Table 2 Results of water Quality tests from Denver and Vicinity
Table 3 Statistical Analysis of Water Quality tests
Average Maximum Minimum EPA’s
Guideline values pH 5.9 7.8 3.0 6.5-9.5 Dissolved Oxygen (ppm) 9.2 9.9 8.2 No guideline Nitrate (mg/l) 2.1 7.2 0.3 10 Conductivity (µs/cm) 2111.1 9740.0 223.0 4.7-5.8 μS/cm Calcium (mg/l) 45.8 89.2 3.2 No guideline Ammonium (mg/l) 0.8 1.8 0.2 No guideline Chloride (mg/l) 58.8 248.5 7.7 250 mg/l
Turbidity (ntu) 10.7 16.6 4.7 0.5-1.0 NTU
pH Dissolved Oxygen (ppm) Nitrate (mg/l) Conductivity (µs) Calcium (mg/l) Ammonium (mg/l) Chloride (mg/l) Turbidity (ntu) Coal Creek Canyon 3.4 9.0 7.2 1011.0 71.3 0.7 248.5 5.6 Tarryall 7.7 9.9 0.3 223.0 31.2 0.3 7.7 4.7 Buckley 7.8 9.5 5.2 9740.0 3.2 0.6 25.8 11.3 Deer Trail 7.6 8.3 0.3 1780.0 51.2 1.8 18.1 14.8 Greeley 3 9.7 0.4 1385 89.2 0.9 60.4 16.2 Golden 4.35 9.5 0.3 340 33.5 0.2 12.2 16.6 Cotopaxi 7.6 8.2 1.3 298.8 41.3 0.8 39.2 5.6 Avg. 5.9 9.2 2.1 2111.1 45.8 0.8 58.8 10.7 Max 7.8 9.9 7.2 9740.0 89.2 1.8 248.5 16.6 Min 3.0 8.2 0.3 223.0 3.2 0.2 7.7 4.7 Standard Deviation 2.2 0.7 2.9 3778.6 30.7 0.6 94.6 5.2
Statistical Analysis
As Tables 2 and 3 show, most of the conducted tests are within the safe drinking water limits that have been set by the EPA. There are no guidelines for ammonium, calcium and dissolved oxygen (DO) from either the Environmental Protection Agency or the World Health Organization. Table 3 shows the average levels of pH, nitrate, and chloride are well below the standards of safe drinking water. The average results for turbidity and conductivity appear to be higher than the safe drinking water standard.
After analyzing Table 2, the highest number that stands out is the conductivity of the Buckley AFB site. The conductivity is unusually high and much higher than the other sample sites, as seen in Figure 2.
Figure 2 Conductivity levels at all sample sites
Depth Correlation
The Buckley AFB site is also the site with the deepest aquifer in our sample area. This led us to believe that there may be other correlations with depth. Figures 3 – 9 are the quality test results compared to the depths of the wells/ aquifers. There appears to be a correlation between depth and pH, calcium, and conductivity.
0.0 1000.0 2000.0 3000.0 4000.0 5000.0 6000.0 7000.0 8000.0 9000.0 10000.0 Conductivity (µs) 1011.0 223.0 9740.0 1780.0 298.8 1385 340
Figure 3 pH and Depth Comparison
Figure 4 Dissolved Oxygen and Depth Comparison
R² = 0.7033
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 0 50 100 150 200 250 300 350 400 450 500pH
Depth (m)pH and Depth Comparison
Polynomial Trend line
R² = 0.2353
0.0 2.0 4.0 6.0 8.0 10.0 12.0 0 50 100 150 200 250 300 350 400 450 500Di
ss
olv
ed
O
xy
gen
Depth (m)
Dissolved Oxygen and Depth Comparison
Polynomial Trend line
Figure 5 Nitrate and Depth Comparison
Figure 6 Calcium and Depth Comparison
R² = 0.2138
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 0 50 100 150 200 250 300 350 400 450 500 N itr ate Depth (m)Nitrate and Depth Comparison
Exponential Trend line
R² = 0.7848
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 0 50 100 150 200 250 300 350 400 450 500Cal
ciu
m
Depth (m)
Calcium and Depth Comparison
Exponential Trend line
Figure 7 Conductivity and Depth Comparison
Figure 8 Ammonium and Depth Comparison
R² = 0.9687
0.0 2000.0 4000.0 6000.0 8000.0 10000.0 12000.0 0 50 100 150 200 250 300 350 400 450 500 Cond uc ti vi ty Depth (m)Conductivity and Depth Comparison
Polynomial Trend line
R² = 0.1398
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 50 100 150 200 250 300 350 400 450 500Ammoniu
m
Depth (m)
Ammonium and Depth Comparison
polynomial Trend line
Figure 9 Chloride and Depth Comparison
Figure 10 Turbidity and Depth Comparison
R² = 0.0512
0.0 50.0 100.0 150.0 200.0 250.0 300.0 0 50 100 150 200 250 300 350 400 450 500Chl
or
id
e
Depth (m)
Chloride and Depth Comparison
Polynomial Trend line
R² = 0.4022
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 0 50 100 150 200 250 300 350 400 450 500Tur
bi
di
ty
Depth (m)
Turbidity and Depth Comparison
Polynomial Trend line
Elevation Correlation professional
According to the EPA, dissolved oxygen concentrations and percent saturation
are related, but not equivalent. Saturation level varies naturally; as water can contain
more DO at lower temperatures, higher pressures, and lower salinities. For example,
100% saturation occurs at low oxygen concentrations at high elevations compared to
low elevations (Hem, 1985). There should be a correlation between elevation and
dissolved oxygen, as elevation increases dissolved oxygen will decrease. Our findings show little change in dissolved oxygen from site to site, as seen in figure 11. Figure 11 also shows little correlation with dissolved oxygen and elevation.
Figure 11 Dissolved Oxygen Levels at all Sample sites
0.0 2.0 4.0 6.0 8.0 10.0
9.0
9.9 9.5
8.3
9.7 9.5
8.2
Disolved OxygenFigure 12 Dissolved Oxygen and Elevation Comparisons
Discussion
Tables 2 and 3 show theCoal Creek Canyon site is unfit for drinking water. This well water is very acidic. With a pH of 3.4 this site is susceptible premature damage to metal piping, and have associated aesthetic problems such as a metallic or sour taste, staining of laundry, and the characteristic "blue-green" staining of sinks and drains. Water with a low pH (< 6.5) could be acidic, soft, and corrosive. This water sample could contain metal ions such as iron, manganese, copper, lead, and zinc, as well as, elevated levels of toxic metals (APEC, 2005).
Although the nitrates from this site are within the safe limits according to the EPA, it is the highest of our samples. High Nitrates in water have been known to cause blue baby syndrome. The main concern of nitrate in drink water is
methaemoglobinaemina, which is also known as blue baby syndrome. The nitrates in drinking water combined with nitrates consumed in other food sources unite with the
R² = 0.3485
0.0 2.0 4.0 6.0 8.0 10.0 12.0 0 500 1000 1500 2000 2500 3000Di
ss
olv
ed
O
xy
gen
(ppm)
Elevation (m)
Dissolved Oxygen and Elevation Comparison
Polynomial Trend line
red blood cells in the body and form methaemoglobin. This reduces the bloods ability to carry oxygen, and reduces the uptake of oxygen to the lungs (Gray, 2005 p.289).
The conductivity of this site is also one of the highest in our sample set.
Conductivity can be indicative of mineralization or salinity problems, which in turn can affect physical properties such as color, taste and odor (Detay, 1997)
The Coal Creek Canyon sample is also has a very high Chloride content. The level of chloride is just blow the safe drinking standard. The standard is 250 mg/l and this sample is 248.5. The toxicity of chloride salts depends on the cation present; that of chloride itself is unknown. Although excessive intake of drinking-water containing sodium chloride at concentrations above 2.5 g/liter has been reported to produce hypertension, this effect is believed to be related to the sodium ion concentration (WHO, 1996).
The Turbidity level is 5.6 which is way above the EPAS Standard of 0.5-1.0 NTU. Turbidity is the measure of relative clarity of a liquid. Clarity is important
When producing drinking water for human consumption. High turbidity levels in drinking water are a problem because excessive turbidity, or cloudiness, in drinking water is aesthetically unappealing, and may also represent a health concern. Turbidity can provide food and shelter for pathogens. If not removed, turbidity can promote regrowth of pathogens in the distribution system, leading to waterborne disease
States and the world. Although turbidity is not a direct indicator of health risk, numerous studies show a strong relationship between removal of turbidity and
removal of protozoa (EPA, 1999). Due to the high levels of turbidity, pH and nitrates, it is our conclusion that the Coal Creek Canyon is unsuitable for human consumption.
The water Sample that we collected from Greely is also not fit for consumption. The pH of this sample is 3, the lowest in our sample set. This sample is as acidic as vinegar. The conductivity and turbidity of this sample is high and way above the
standards of safe drinking water. However, the nitrates and Chloride of this sample are within the limits of the EPA standards. This sample also has high levels of Dissolved oxygen, Calcium and Ammonium.
The sample taken from Golden is a bit better, but in our opinion it is not fit for drinking water. The pH levels of this sample is 4.35, which is better, but is still not within the drinking water standards. The Turbidity and Conductivity of these samples are also higher than the drinking water standards. However, the Nitrates and chloride of this sample are well within the safe drinking standards. This sample also has high levels of Dissolved oxygen, and Calcium. It is our conclusion that the Golden sample is unsuitable for human consumption.
The Tarryall sample is much different from the above samples. The pH of The Tarryall sample is 7.7, which is in the recommended limits of the EPA. The Nitrate and Chloride tests of this sample are also within limits of the drinking water standards.
However the Conductivity and Turbidity of this sample is way above the standards. However, out of our sample set Tarryall has the lowest level of turbidity. The Buckley, Cotopaxi and Deer Creek samples also have ph levels, Nitrate and Chloride within normal limits. These sites also have high Levels of Conductivity and Turbidity. Buckley has the highest Conductivity levels of all the sample sites. Due to these high levels we recommend that further testing be done at all four sites before we can say for certain that this water is safe for drinking.
Many of our sample sites had high levels of Dissolved Oxygen, Calcium, and Ammonium. As of this place in time there are no regulator standards held by the EPA or the World health organization on the effects of Dissolved Oxygen, Calcium, and Ammonium. Because of these high levels in our water samples we recommend that all sites in our study area should be analyzed further before a true assessment of drinking water quality.
The Buckley, Deer Creek and Tarryall sites are the deepest well water samples that we collected. These water samples had the highest amounts of Conductivity. This Finding leads us to believe that there may be a collation between the tests we conducted and the depth of the well. After processing the data and calculating numbers we discovered several depth colorations. These graphs can be viewed in figures 2 thru 9. The highest test variable that correlated with depth was Conductivity. The polynomial trend line shows a high polynomial relationship between depth and conductivity. The
polynomial coefficient between depth and conductivity is very high at this alludes to the possibility that as depth increases so does conductivity. There also appears to be correlations between pH, Calcium and possibly Turbidity. Our results show high colorations. However, we recommended that further testing be done to confirm this Hypothesis.
Conclusion
Our findings indicate that the CCC well water is unhealthy to drink, due to nitrates and turbidity above the safe standards and pH below the safe standards. The Greeley and Golden waters are also unhealthy due to low pH, and high conductivity and turbidity. Tarryall is also unfit to drink because of high conductivity and turbidity. The Buckley AFB water has the highest conductivity in our study, and is also the deepest well. We believe depth and conductivity are strongly related. Our findings at this site indicate that as well depth increases, so does conductivity. More testing should be done to investigate this hypothesis further.
In conclusion, we recommend further testing on all our well sites. Our tests are just simple, general tests. We recommend more detailed tests be performed that might include organic and inorganic contaminants, VOCs, and bacteria. Any homeowner can send a sample of their water to a lab and get a full and complete quality test performed for a small fee. We recommend all private domestic well owners regularly test their water and adapt any filtration system accordingly. Again, in the state of Colorado, the
responsibility of safe water quality and well maintenance fall on the shoulders of the well owner.
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Gray N.F., 2005, Water Technology and introduction for Environmental scientist and Engineers; Elesier Butterworth- Hieman
Hem JD (1985) Study and Interpretation of the Chemical Characteristics of Natural Water (3rd edition). U.S. Geological Survey, Water Supply Paper 2254. AAPEC (2005) pH Values of water explained, December 3 2010,
http://www.freedrinkingwater.com/water-education/quality-water-ph.htm Alp MT., Kocer MAT., Sen B., Ozbay O. 2010. Water quality of surface waters in lower
Euphrates Basin. Journal of Animal and Veterinary Advances9 (18): 2412-2421. Burrow RK., Nolan BT., Rupert MG., Dubrovsy NM. 2010. Nitrate in groundwater of
the United States 1991-2003. Environmental Science & Technology44: 4988-4997. Colorado Dept. of Health & Env. 2000. Water quality in Colorado. Water Quality
Control Division: 16 p.
Department of National Health and Welfare (Canada) Guidelines for Canadian drinking water quality. Supporting documentation. Ottawa, 1978
DeSimone LA., Hamilton PA., Gilliom RJ. 2009. Quality of groundwater from private domestic wells. Water Well Journal: 6 p.
Detay, M., 1997, Water well: Implementation, Maintenance and Restoration, John Wiley and sons, Chichester.
EPA, 1999, IMPORTANCE OF TURBIDITY, EPA Guidance Manual Turbidity Provisions
Focazio MJ., Tipton D., Dunkle Shapiro S., Geiger LH. 2006. The chemical quality of self-supplied domestic well water in the United States. Ground Water Monitoing & Remediation26(3): 92-104.
Helmus AM., Fernald AG., VanLeeuwen DM., Abbott LB., Ulery AL., Baker TT. 2009. Surface water seepage effects on shallow ground-water quality along the Rio Grande in northern New Mexico. Journal of the American Water Resources Association45(2): 407 – 418.
Hem JD. 1985. Study and interpretation of the chemical characteristics of natural water. 3rd edition. USGS water supply paper. 2254.
Aknowledgements:
C.Brady – Abstract, Introduction, Literature Review, Study Area, Methods, Conclusion
