Useful information on groundwater is usually available from well drillers in the area or the state geological survey. Frequently, states have aquifer maps as well as other important information on water quantity and quality. Test wells may be necessary to ensure that an adequate flow is available, especially for large operations where rapid filling or flushing is required. Often it must be aerated before it is introduced into the system. Chemical analyses of well water for ammonia, contaminants, dissolved oxygen, etc. are essential before they are developed for aquaculture.
Surface waters represent an alternative water supply.
They are frequently less expensive to develop and pump than ground water, but have restrictions that present problems for the farmer. Surface waters may be more variable with regard to flow, temperature, and quality. Chemical and biological contaminants may also be present. Water must be filtered or screened to eliminate unwanted fish and insect larvae. Other treatments such as aeration or filtration to remove particulates may be necessary.