The city of St. Petersburg, Florida, is a largely residential peninsular community located on Florida’s west-central coast. It is bound on the east and south by Tampa Bay and on the west by the Gulf of Mexico. St. Petersburg has a population of approximately 250,000. The Tampa Bay area receives an average of 140 centimeters (cm) (55 inches [in]) of rainfall annually, nearly half of which falls during the months of June, July, and August. Approximately 100 cm (40 in) of the 140 cm (55 in) are lost to evapotranspiration, leaving only 40 cm (15 in) available for potable and other uses. Due to the region’s flat topography, there is little opportunity to impound water as a water supply source. Thus, while some of the rainfall percolates into the underground and enhances the groundwater supply, the majority of the rainfall remaining after evapotranspiration becomes runoff and eventually flows into the sea. The water supply problem is further compounded by a continuing influx of new residents to the area, many of whom choose to live in coastal areas where the groundwater supply is most limited because of seawater intrusion.
St. Petersburg has no significant surface water or groundwater suitable for potable water supplies within its corporate boundaries. As a result, water is obtained from adjacent counties from which several other municipal governments also obtain their water supplies. This situation, coupled with restrictive wastewater discharge requirements, led St. Petersburg to develop one of the largest urban water reuse systems in the world.
The initial portion of the retrofit system went into operation in 1977. Since that time it has grown both in volume of reclaimed water delivered and number