There are a variety of reasons that cause a well to stop working or perform poorly. Some are fixable, however some are not or are very expensive to fix. The water supply may have depleted the water aquifers to low levels, meaning there is less water in the ground and the well has to work harder to pump it out. Another source of slow flows are clogs that can develop from a variety of materials including clay, silt, calcium carbonate, iron bacteria, setiment, and other deposits. The use of chemicals and brushes are common techniques for removing well clogs, but can prove costly. Human errors can also contribute to well problems including: poor well design, construction, and operation of the well. Well rehabilitation is a process that revitalizes wells that are no longer working or have experienced reduced flows over time, improving their performance and efficiency. When considering a well rehabilitation project, a professional should be consulted to assess the status of the well if the reason for failure is not apparent. Once a professional is contacted, some form of well testing is typically needed to specify the exact problem and potential solutions.