A good way to start this topic is to use the SEPUP activity, Investigating Groundwater: The Fruitvale Story. These kits are available to all New Haven science teachers with training provided on the use of the kits. This activity has them find the source of groundwater contamination by sampling water from certain wells in the area. This activity leads to an understanding of groundwater movement and they become familiar with terms such as porosity, permeability and aquifers.
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Wells can be dug in a variety of ways as you can see from the diagram taken from Water Science for Schools, Groundwater: Wells. They can be dug by hand, driven or drilled but, they all have one thing in common. They must be deep enough to stay below the water table all year long. Approximately 500,000 people use well water for drinking in Connecticut. Most of this well water is not tested for pesticides. Recently 53 homeowners volunteered to have their wells tested for pesticides. Seventy-two percent used pesticides either on their lawns and/or trees. Eleven percent of the tested wells contained trace levels of pesticides. Five of the wells had more than one pesticide present. However, this does not mean if you do not use pesticides, pesticides will not contaminate your well. If you performed the Fruitvale investigation, the student will better understand how these underground formations differ in supplying water for a well. These underground formations are also the reason why some wells run dry each year while the neighbors well does not have a problem.
Well water in Connecticut frequently has problems such as hardness, taste, odor and staining which are objectionable to the user. Filter screens on faucets may also become clogged with debris from the well. The good news is that having some sort of filtration system installed probably can solve these types of problems.
Your well water should be tested periodically for nitrate and coliform bacteria. If contaminants are present and they exceed the standard, contact the Public Health Department for assistance.
There are a number of steps one should take if they are using a well for their water supply. The following is a list of suggestions taken from the website: http://www.epa.gov/safewater/pwells1.html
- Periodically inspect exposed parts of the well for problems such as:
- cracked, corroded, or damaged well casing. - broken or missing well cap. - settling and cracking of surface seals.
- Slope the area around the well to drain surface runoff away from the well.
- Install a well cap or sanitary seal to prevent unauthorized use of, or entry into, the well.
- Have the well tested once a year for coliform bacteria, nitrates, and other constituents of concern.
- Keep accurate records of any well maintenance, such as disinfectant or sediment removal, that may require the use of chemicals in the well.
- Hire a certified well driller for any new well construction, modification, or abandonment and closure.
- Avoid mixing or using pesticides, fertilizers, herbicides, degreasers, fuels, and other pollutants near the well.
- Do not dispose of wastes in dry wells or in abandoned wells.
- Do not cut off the well casing below the land surface.
- Pump and inspect septic systems as often asrecommended by your local health department.
- Never dispose of hazardous materials in a septic system.
If you do/did not have access to the SEPUP investigation, we should make sure the student understands what is meant by groundwater and why it is important to have a safe reliable source of groundwater.
Ground water is the source for well water. This water fills in the spaces inside the earth. The top of this underground water is called the water table. As the water table fluctuates with the seasons, it is important the well be deep enough to always be below the water table.
Approximately 50% of the people use groundwater for drinking. Groundwater moves through what we call aquifers (spaces in soil and rock.) The speed at which the water moves depends on the size of the spaces and how they are connected. If the material above the aquifer is permeable, then it is easier for pollutants to enter the system.
The main means wells become polluted are from landfills, septic tanks, leaky underground gas tanks and over use of pesticides/fertilizers.
Congress originally passed the Safe Drinking Water Act in 1974. This Act was put in place to protect the public by regulating the nation’s public drinking water. Maximum contaminant levels (MCLs) have been put in place for our drinking water. Secondary MCLs are also used to control odor, taste and appearance. However, these standards do not apply to water supplies that do not have at least15 connections.
Remember there are some naturally occurring pollutants to our groundwater system that we might not be aware. Remember it your responsibility to insure your well water is safe too drink for you and your family.
Here are some tips taken from: http://www.msuc.edu/genescc/natres/groundwater.htm
1. Recycle - Less chance of polluted water entering the well.
2. Use native plants for landscaping- Adapted to climate and pest, less need for fertilizers and pesticides.
3. Plug up unused wells.- Prevents contaminants from entering groundwater system.
4. Use good fertilizer practices.
5. Divert and/or contain stormwater.