Casselberry is an established Seminole County suburb that grew up around the Triplet Chain of Lakes and incorporated back in 1940. Today it runs largely on municipal water, so most homes here are not on a private well.
Wells are on older and lakefront lots that kept a private well, and on homes that run a separate irrigation well to keep a mature lawn green. Those wells draw from the Floridan Aquifer, commonly 100 to 400 feet down, through Central Florida limestone that leaves hardness and mineral scale inside pumps, tanks, and check valves over time.