Evaluation of chloride contributions from major point and nonpoint sources in a northern U.S. state.

Chloride pollution of groundwater and surface water resources is an environmental concern in many regions. While use of road salt for winter road maintenance is known to be a major source of chloride in the environment, limited research has investigated the environmental impacts of chloride discharged from water softeners, particularly in areas with hard water. A chloride budget was developed for the state of Minnesota to estimate the amount of chloride discharged from household water softeners as well as other domestic, agricultural, commercial, and industrial sources. The analysis used multiple data sources, including salt sales records and wastewater monitoring data, and used statistical, spatial, and survey methods to estimate chloride loading from major sources statewide. Annual chloride mass contributions were estimated for the following sources: household water softener use; human excretions; household product use; chloride concentrations in drinking water; atmospheric deposition; road salt use; dust suppressant use; fertilizer application; industrial discharge; and livestock excretions. A mass balance for 96 wastewater treatment plants with effluent monitoring data showed that across these facilities, discharge from water softeners was the largest chloride source. A statewide chloride budget found that road salt was the largest source of chloride to the environment, but that WWTPs and fertilizer were also substantial sources, discharging 221,300 t and 209,900 t annually. Water softeners were estimated to contribute 65% of the chloride discharged to all 613 municipal WWTPs statewide. Methods used in this analysis could be applied to other communities, watersheds, or states with similar conditions. The results of the analyses indicate that water softening is an important chloride source in areas with hard water and underscore the importance of identifying and characterizing chloride sources in less urban areas, where deicing salt may be a less important contributor and receiving water bodies are often lakes, reservoirs, and streams.

On-plot drinking water supplies and health: A systematic review.

Many studies have found that household access to water supplies near or within the household plot can reduce the probability of diarrhea, trachoma, and other water-related diseases, and it is generally accepted that on-plot water supplies produce health benefits for households. However, the body of research literature has not been analyzed to weigh the evidence supporting this. A systematic review was conducted to investigate the impacts of on-plot water supplies on diarrhea, trachoma, child growth, and water-related diseases, to further examine the relationship between household health and distance to water source and to assess whether on-plot water supplies generate health gains for households. Studies provide evidence that households with on-plot water supplies experience fewer diarrheal and helminth infections and greater child height. Findings suggest that water-washed (hygiene associated) diseases are more strongly impacted by on-plot water access than waterborne diseases. Few studies analyzed the effects of on-plot water access on quantity of domestic water used, hygiene behavior, and use of multiple water sources, and the lack of evidence for these relationships reveals an important gap in current literature. The review findings indicate that on-plot water access is a useful health indicator and benchmark for the progressive realization of the Sustainable Development Goal target of universal safe water access as well as the human right to safe water.

Does global progress on sanitation really lag behind water? An analysis of global progress on community- and household-level access to safe water and sanitation.

Safe drinking water and sanitation are important determinants of human health and wellbeing and have recently been declared human rights by the international community. Increased access to both were included in the Millennium Development Goals under a single dedicated target for 2015. This target was reached in 2010 for water but sanitation will fall short; however, there is an important difference in the benchmarks used for assessing global access. For drinking water the benchmark is community-level access whilst for sanitation it is household-level access, so a pit latrine shared between households does not count toward the Millennium Development Goal (MDG) target. We estimated global progress for water and sanitation under two scenarios: with equivalent household- and community-level benchmarks. Our results demonstrate that the "sanitation deficit" is apparent only when household-level sanitation access is contrasted with community-level water access. When equivalent benchmarks are used for water and sanitation, the global deficit is as great for water as it is for sanitation, and sanitation progress in the MDG-period (1990-2015) outstrips that in water. As both drinking water and sanitation access yield greater benefits at the household-level than at the community-level, we conclude that any post-2015 goals should consider a household-level benchmark for both.