Providence Water sells water to approximately 76,800 retail customer connections including houses and businesses in Providence, Johnston, North Providence, Cranston and East Smithfield and to 7 wholesale communities serving a number of additional municipalities within the State. Providence Water presently supplies approximately 60 percent of the state's drinking water. Of the water produced, 36 percent is supplied to the residents of Providence, 22 percent to the retail districts outside of Providence, and 42 percent goes to the wholesale water districts.
Finished water is transmitted from the treatment plant to the distribution system through two major transmission lines. The first major transmission line, the 90-inch diameter Scituate Tunnel and Aqueduct, transports water from the treatment plant to the distribution system in an easterly direction, generally along a route that parallels Route 12, ending at the siphon chamber near Interstate 295. From the siphon chamber the transmission line splits into two lines, a 60-inch diameter concrete conduit, and a 66-inch diameter steel pipeline. The 60-inch line continues to feed the Neutaconkanut and Bath Street Pumping Stations and the Neutaconkanut Distribution Storage Reservoir. The 66-inch line continues to the general area of Budlong Road in Cranston from where further distribution begins. The second major transmission line is the Supplemental Tunnel and Aqueduct. This Supplemental Tunnel and Aqueduct starts off as a 78-inch diameter conduit at the treatment plant and transports water in a southeasterly direction through the northern section of West Warwick. At this point, the transmission line expands to 102 inches in diameter and turns northerly to terminate in the general area of Budlong Road in Cranston where further distribution begins. The capacity of the 90-inch line is 100 MGD and the capacity of the 78 and 102-inch lines is 77 MGD.
The retail distribution system is serviced by three separate pressure zones. The Low Service Area maintains pressures between 37 and 98 PSI at the customer tap and serves areas with elevations of 0-140 ft above sea level. This zone delivers approximately 71.5 % of the total retail water. The High Service Area supplies consumers at elevations of 140-220 ft above sea level with pressures ranging from 36 to 71 PSI. The Extra High Service Area services those customers 220 ft above sea level with pressures between 36 and 77 PSI.
Providence Water has six storage reservoirs in its system. The capacity of these reservoirs range from 1.0 MGD to 43.4 MGD. Although the majority of the system is fed by gravity, Providence Water does own and operate various pump stations throughout the system to pump water to services areas at higher elevations.