As wastewater treatment plant permit conditions have become stricter in recent years, Pima County has urged that standards be relaxed or that streambed releases be discontinued. The cost of building distribution systems for use can be high, especially for golf courses or other facilities far from the treatment plant and usually requiring uphill pumping. Effluent, however, is regulated with regards to its water quality. Although effluent is treated, it still contains some contaminants that can affect groundwater. These include nitrates which have been found in groundwater in the Marana area and are probably the result of both agricultural activity and effluent.
Excess nitrates can cause serious problems for infants.