Groundwater is vulnerable to overdraft and depletion, especially in relatively dry regions where natural recharge rates are very low and groundwater is the main source of water. Artificial recharge of groundwater with treated wastewater has been widely adopted as a technique to replenish the overdraft aquifers. Indeed, in the USA, the technique has been practised for a long time. In 1981, a design procedure manual was developed for practitioners by the United States Environmental Protection Agency (USEPA). It was updated in 1984 and lastly in 2006. However, the design procedure has not been fully generalized for the different situations and has not been fully formalized in order to allow its automated implementation on calculation software (i.e. spreadsheet). Therefore, in this paper we formalized and generalized the USEPA design procedure to achieve an automated iterative method of calculation which can be easily implemented in a spreadsheet.