My mother's house is near the spring-fed town water supply, so the water table is quite high. Except in the middle of the summer, her sump pump runs frequently. IF you are tapping the water table, nothing much you can do about it except move. You can test the water to see if it is ground water verses piped water from the city. If it is piped water from the city, it would have their typical mix of chemicals in it. The ground water typically wouldn't. If it is a water main leak, you might get the city to fix it. If it is ground water, not much you can do. the water table can have dips and peaks, depending on the soil conditions (sand, clay, stone, etc.).