WHY OUR MISSION IS IMPORTANT
About 60% of the water supplied to Laramie residents comes from the Casper Aquifer. In addition, several hundred residents near the city depend on the Casper Aquifer for 100% of their drinking water.
Locally, the Casper Aquifer is recharged in the area extending approximately from Boulder Drive to the Laramie Range east of the city.
Find out how to support our mission...
On August 3, the Albany County / Laramie Environmental Advisory Committee received the results of US Geological Survey sampling of two monitor wells on the east side of town drilled as part of the 2015 Laramie Monitor Well Program. The “Imperial Heights Park South” well is off the northwest corner of the Sherman Hills Subdivision; the “Triangle” well is at the intersection of Vista Dr. and Grand Ave. These wells were not located within areas served by septic systems, but were sited to monitor groundwater quality between such areas and the City’s Turner Wellfield.
Consistent with the City report, but including a much larger set of chemicals, the USGS sampling found nothing in excess of EPA-established maximum contaminant limits for drinking water.
Nitrates, sodium, and chlorides were described as “elevated” relative to other Casper Aquifer wells in the area. Isotopic analysis of nitrates ruled out fertilizer and precipitation sources, but could not distinguish between septic waste and natural soil contributions.
The samples were also analyzed for 65 different “wastewater compounds” that are “common in septic system effluent”, like caffeine and birth-control hormones. None were detected. Thus, the information from these two wells indicates these contaminants that may be present within the areas of septic systems are not making their way toward the city wells at detectable concentrations.
Tritium analysis indicates the groundwater at these locations recharged the aquifer later than the 1950s.
What is groundwater contamination?
While rocks and soil do provide some filtering action, they don’t filter everything. Toxic materials, or contaminants, can still travel into the groundwater. Contaminants can enter in aquifer the same way that water enters it. For example, if oil spills onto the ground, it can soak in and end up in the water we drink. So can other chemicals and things that can harm people and animals.
In fact, groundwater contamination is a serious problem faced by cities throughout the United States. Laramie’s groundwater is particularly vulnerable to contamination because of the high permeability of the surface soils, because the Casper Formation is fractured and faulted, and because Interstate-80 cuts through the entire thickness of the Casper Formation.
Some people are tempted to think that aquifers can be “naturally protected” by clay layers in the earth. Unfortunately, this isn’t quite true, either. Water will gradually but continually make its way around the edges of any clay layers it encounters, or through any cracks, carrying contaminants into the groundwater below.
Groundwater contamination is a particularly troublesome form of pollution. For one thing, many toxic water pollutants cannot be seen, smelled, or tasted, so you may not even be able to tell if they’re in a glass of water you are about to drink. Complicated and expensive laboratory tests are often required to identify them.
In addition, contaminants often remain in groundwater for a very long time and can be extremely costly to remove. Because of groundwater’s slow rate of movement, and limited biochemical activity, contaminants are likely to remain in the groundwater for hundreds of years. Expensive drilling and sampling techniques are required to find out which contaminants are present and how far they’ve spread. Alternative water supplies must be provided while the contamination is cleaned up. And the process of cleaning a polluted groundwater site can cost millions of dollars and take dozens of years. Even then it’s not always successful. Some polluted aquifers may never be completely restored.
We threaten groundwater quality in our individual lives by exposing the groundwater to substances such as pesticides, fertilizers, gasoline, motor oil, household cleaners, paints, and leaky septic systems. It takes only a very small quantity of some of these contaminants to degrade all of the water in an aquifer. Only one quart of oil, for example, can contaminate up to a quarter of a million gallons of drinking water.