Use the Symptom/Cure Approach
Make a list of water symptoms. Common symptoms include reduced flow to the house, the appearance of sediment in the water, any change in water quality such as odor or taste, and spurting fixtures that yield discolored water.
Match your water symptoms with possible causes. Reduced water yield is attributed to several factors: low water table, incrustation buildup on the casing and screens, overpumping or poor construction.
The presence of sediment in your water can mean your casing is failing, there is corrosion present, you are overpumping the well or it was poorly designed.
Changes in water quality can point to corrosion, contamination or biofouling.
Spurting fixtures with cloudy water usually mean there are gases such as methane or carbon dioxide present.
Take a water sample. You can buy simple home water testing kits at your local home improvement store. By testing your own water, you'll save money and time. Your water problems may be as simple as installing a filtration system to filter out unwanted elements.
Call in a contractor or plumber to do a well inspection. Your water problems may be resolved by a simple shock chlorination, or the well may need cleaning with brushing, fracking or high-pressure jetting.