What is a well cap and what does it do?
The well cap is the cover on top of the well casing that sticks out of the ground. It serves many purposes. Most caps, which are usually aluminum or a thermoplastic, include a vented screen so that the pressure difference between the inside and outside of the well casing may be equalized when water is pumped from the well. However, the cap’s main function is to keep contaminants out of the water supply. What type of contaminants does the well cap keep out of the well? A properly sealed well cap protects against all types of contamination. It is the first line of protection against nonpoint source pollution, which constitutes the majority of ground water contamination. Nonpoint source pollution includes runoff of pesticides and herbicides, soil erosion, and elements from the street. Well caps also keep out insects, such as earwigs, which prefer a dark, damp environment to nest. Insects can cause major problems in a well. Bacteria levels can rise from their droppings, and sometimes the b
