In March, the Environmental Protection Agency published its 2015 Drinking Water Infrastructure Needs Survey and Assessment (DWIN- SA). The report concluded, “The nation’s drinking water utilities need $472.6 billion in infrastructure investments over the next 20 years for thousands of miles of pipe as well as thousands of treatment plants, storage tanks, and other key assets to ensure the public health, security, and economic well-being of our cities, towns, and communities.” This estimate represents Drinking Water State Revolving Fund (DWSRF)- eligible infrastructure projects necessary from Jan. 1, 2015, through Dec. 31, 2034. The national total comprises the infrastructure investment needs of the nation’s approximately 49,250 community water systems, 21,400 not- for-profit noncommunity water systems, American Indian water sys- tems, and Alaska Native Village water systems. The DWINSA relied primarily on a statistical survey of public water systems. The survey response rate was 99.7 percent (2,592 responses from 2,600 systems surveyed), the highest response rate in the history of the DWINSA, providing a high degree of confidence in the statistical precision of the assessment’s findings, according to EPA. The estimate covers infrastructure needs that are eligible for (but not necessarily financed by) the DWSRF, including installation of new drinking water infrastructure and rehabilitation, expansion, or replace- ment of existing infrastructure. The reported projects may be needed to address existing infrastructure that is deteriorated or undersized, ensure compliance with regulations, provide system resilience, im- prove energy efficiency, or improve cost effectiveness. Cost estimates include engineering and design, purchase of raw materials and equip- ment, construction and installation labor, and final inspection. EPA conducted five previous DWINSAs in 1995, 1999, 2003, 2007, and 2011. Total national need increased by about 1 percent in both the 2007 and 2011 Assessments, essentially the same statistical result as the 2003 findings. However, the 2015 assessment reveals a 10 per- cent increase in the estimate of total national need, with survey data Survey of drinking water infrastructure needs EPA report documents the growing cost to fix the nation’s drinking water systems.
Figure 1: Total 20-year need by project category (billions of January 2015 dollars). Image: U.S. Environmental Protection Agency
indicating the largest increase in rehabilitation and replacement needs for existing infrastructure, specifically in the water transmission and distribution project category. This increase was seen in both medium- and large-sized systems. EPA grouped water system infrastructure needs into four major catego- ries based on project type (see Figure 1 and Table 1): • drinking water source, • transmission and distribution, • treatment, and • storage. An additional “other” category comprises projects that do not fit into one of the four, such as system-wide supervisory control and data ac- quisition (SCADA) or emergency generators. Source water needs include construction or rehabilitation of surface water intake structures, drilled wells, and spring collectors. Needs for dams and raw water reservoirs, which are not eligible for DWSRF funding, are excluded from the assessment. The transmission and distribution category includes projects for reha- bilitation and replacement of existing water mains, installing new pipe to eliminate dead end mains and the resulting stagnant water, install- ing new mains in areas where existing homes do not have a safe and adequate water supply, and installing or rehabilitating pumping sta- tions to maintain adequate pressure. It also includes projects to address replacement of appurtenances, such as meters to record flow and water consumption, backflow-prevention devices to avoid contamination, and valves for controlling flows and isolating problem areas during repairs. The treatment category includes construction, expansion, and rehabili- tation of facilities to reduce contamination through treatment processes. Treatment systems range from a simple chlorinator for disinfection to a complete conventional treatment system with sedimentation, filtra-
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july 2018
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