Is there a risk of contamination with different casing materials?

Material Corrosion and Leaching

When selecting a water well casing material, it’s essential to consider the potential for corrosion and leaching. For example, galvanized steel casings can corrode and release zinc into the surrounding soil and water, contaminating the aquifer. Similarly, PVC casings can leach chemicals such as phthalates and BPA into the water. In contrast, fiberglass-reinforced plastic (FRP) casings are generally non-reactive and non-toxic, making them a popular choice for groundwater wells.

Casing Material Options and Standards

The American Society of Testing and Materials (ASTM) and the American Water Works Association (AWWA) have established standards for water well casing materials. For instance, AWWA C-200 specifies the requirements for steel and ductile iron casings, while AWWA C-900 covers PVC casings. When selecting a casing material, it’s crucial to ensure that it meets or exceeds these standards to minimize the risk of contamination. For example, a 2-inch thick steel casing with a minimum yield strength of 35,000 pounds per square inch (psi) would meet the AWWA C-200 standard.

Inspection and Maintenance

Regular inspection and maintenance of the water well casing are critical to preventing contamination. This includes monitoring the casing for signs of corrosion or damage, such as cracks or leaks, and performing regular disinfection and sanitization of the well. For example, a well owner might use a 10% bleach solution to disinfect the casing every 6 months. By following these guidelines, you can help ensure the integrity of your water well casing and prevent contamination.