Due to intensive urban, industrial and agricultural activities, surface water resources are at risk of severe pollution. Specific pollutants are defined by Water Framework Directive as the pollutants those are discharged to the water resources in significant amounts. These pollutants have various adverse effects on the aquatic organisms and humans exposed to them through different pathways. Identification and control of specific pollutants is an obligation under Water Framework Directive (2000/60/EC), in order to reach “good water quality” in all waters and ensure healthy water environment for different use alternatives. Control of specific pollutants in surface waters are ensured by the implementation of their environmental quality standards (EQS), concentrations in water, sediment or biota which should not be exceeded in order to protect human health and the environment.
As a candidate for EU membership, Turkey, has conducted comprehensive studies to determine the river basin specific pollutants and deriving environmental quality standards for these pollutants. Within the scope of these studies, point and diffuse pollutant sources were identified and pollutants that would be discharged by these sources were specified. Specific pollutants identified by other EU countries and pollutants listed in international agreements were also considered and all those chemicals were listed as “universe of chemicals”.
Following the constitution of initial chemicals list, COMMPS method was used to determine the final specific pollutants list. By this method, chemicals were ranked according to their usage amount, physicochemical properties, toxicity, potential to be present in wastewater, and environmental fate. In addition to this, two simple methods were also used to rank the chemicals for which usage data was not available. Moreover, monitoring studies were carried out to detect the levels of these pollutants in receiving water bodies and wastewater discharges. The outputs of the 3 methods and monitoring studies were combined and 117 point-sourced and 133 diffuse-sourced specific pollutants were assigned.
In order to derive the environmental quality standards for specific pollutants, acute and chronic toxicity data was collected from the literature and assessed statistically. The level which is safe for 95 % of the population was selected as the environmental quality standard generally.
The specific pollutants and the corresponding environmental quality standards were incorporated into By-Law on Surface Water Quality Management. According to the provisions of the by-law, environmental quality standards for specific pollutants must be met by the end of 2019. Therefore, monitoring programs including specific pollutants have been prepared for 25 river basins. Currently, efforts are put to reveal the measures to achieve the environmental quality standards. The study is an outstanding example of bridging science and policy in water quality management since it directly makes use of the outcomes of scientific studies in policy making.
Water quality standards and numeric criteria are developed to protect and define when waterbodies support their designated uses. Recreation is a common use type that most waterbodies are required to support. This use category includes swimming, wading by children, boating, water skiing, whitewater sports, and other recreational activities. Routinely, uses in this category are divided into primary and secondary contact relative to the likelihood that water ingestion may occur during the activity. Long-term geometric mean concentrations of fecal indicator bacteria from all flow conditions provide the basis for assessments to determine designated use support. This paper evaluates the effect of implementing an alternative water quality standards approach for contact recreation based on flow condition (safe vs. unsafe) and the type and volume of use. This effectively separates water quality samples based on hydrologic conditions for assessment purposes. Using this approach, high-flow event data considered in some assessments can be assessed differently without jeopardizing public health.
A case study performed on the Navasota River in Central Texas, USA evaluated data collected over a two-year period and separated it by flow condition to test for significant differences in median fecal indicator bacteria (Escherichia coli) concentrations between conditions. A maximum flow threshold for safe recreation (swimming, children wading) was established at 2.12 m3/s based on average depth and velocity at the monitored location. Statistical analysis using nonparametric tests suggests that significant differences in median E. coli concentrations exist between safe and unsafe flow categories but not between safe and all flows. This suggests that an alternative water quality standard that allows exclusion or re-categorizing E. coli concentrations above established thresholds may produce a different assessment outcome. Under the current assessment scheme where all flows are considered, the geometric mean of assessed data is 150.1 cfu/100 mL; however, re-categorizing and excluding high-flow data from the assessment yields a geometric mean of 106.4 cfu/100mL. This value meets the current standard of 126 cfu/100mL. Using this approach in other waterbodies may result in currently impaired waters meeting water quality standards.
Adopting this approach requires a shift from current water quality policy. Contact recreation standards are currently applied to all hydrologic conditions. Logic suggests that this is not appropriate since all types of contact recreation should not occur in streams during unsafe flow conditions. Water quality concerns are secondary to physical safety concerns and the increased risk of drowning. Persons engaging in contact recreation during unsafe hydrologic conditions assume increased risks inherent to the activity. This should also apply to water quality conditions. However, extreme sport enthusiasts have successfully argued that unsafe flow conditions should not be exempted from applicable water quality standards. As a result, numerous waterbodies are considered impaired because of E. coli data collected during unsafe hydrologic conditions. Implementing an alternative approach to water quality standards for contact recreation assessments can still protect human health while also minimizing the costs taxpayers incur to restore impaired waterbodies.
Studies on harmonization and implementation of EU Water Framework Directive in Turkey were launched in 2011 by the Turkish Ministry of Forestry and Water Affairs (MoFWA). Within the scope of these studies river basin based biological monitoring surveys were initiated in 2012. In the early stages of biological surveys, common indices generally used in academic researches were used. However, these indices do not contain lots of species endemic to Turkey and were not tested whether they correspond to Turkish situation. Thus the resulting ecological status values were considered as inadequate in terms of their confidence and precision. In order to overcome these difficulties and to define the country specific biological indices, a Project on “Establishment of the Water Quality Ecological Assessment System Specific for Turkey” was initiated in 2014.
In this study, the most suitable biological indices for each biological quality elements and for each water body categories have been determined and adapted to Turkish conditions by using the inventory results of 25 river basins in Turkey and monitoring results in 8 river basins (Sakarya, Ceyhan, Kuzey Ege, Batı Akdeniz, Batı Karadeniz, Doğu Karadeniz, Aras basins and Aşağı Fırat sub basin) representing the different climatic and geographical conditions in Turkey. Within the scope of monitoring activities, 218 rivers, 69 lakes, 15 transitional waters and 31 coastal waters were monitored biologically, chemically and hydromorphologically for 4 monitoring campaigns. Moreover the potential reference sites and reference conditions in the 8 pilot river basins were defined.
As a result of this study, various biological indices were proposed to be used in Turkey. These indices are as follows: multimetric indices in rivers and lakes, Turkish Benthic Index (TUBI) in transitional and coastal waters for benthic macroinvertabrates; adapted Med-PTI in lakes, chlorophyll a and diversity indices in transitional and coastal waters for phytoplankton; Trophic Index for Turkey (TIT) for phytobenthos (diatoms); adapted IBI in rivers and lakes, adapted ELFI in transitional waters for fish fauna; IBMR in rivers, Lake Leafpacks 2 in lakes for macrophytes; EEI in transitional and coastal waters for macroalgae and angiosperm. Moreover, reference conditions of the reference sites in 8 basins, aquatic flora and fauna lists of the country, class boundaries for the proposed indices and ecological status of the 8 pilot basin were determined. This Project is recognised as an important step for establishment of the ecological assessment system in Turkey and the project guided MoFWA to define the next steps for finalising the ecological assessment system such as establishment of the reference monitoring network in 25 basins of Turkey, definition of type specific reference conditions for all types, definition of the ecoregions of Turkey in order to revise the typology system in Turkey.
The Clean Water Act of 1972 is the primary federal law in the United States governing water pollution. The impairment of rivers and streams by pathogens as indicated by the presence of high concentrations of Escherichia coli has been a problem in Texas for many years. Over half of the waterbodies designated for contact recreation and assessed in Texas are listed as impaired by bacteria. In practice, waterbodies are generally expected to support fishing and recreational swimming. The surface water quality standard of 126 cfu/100 mL E. coli was established by the US Environmental Protection Agency (EPA) to reflect an epidemiologic correlation with about 36 cases of gastrointestinal illness per 1,000 recreation events. However, the epidemiologic studies predominantly assessed illness caused by human-derived bacteria sources such as treated and untreated discharge from wastewater treatment plants and malfunctioning septic systems. Bacterial Source Tracking (BST) includes a suite of methods for determining E. coli sources and has been used to characterize E. coli collected in 11 predominantly rural watersheds in Texas. On average, sources in a three-way split were 51% wildlife, 27% domestic animals, and 10% human, with 12% of isolates unidentified. Human health risk from exposure to human and non-human wastes as indicated through waterborne E. coli concentrations varies substantially. Quantitative Microbial Risk Assessment (QMRA) has recently been applied in a Texas watershed to assess the effectiveness of the established E. coli surface water quality standard for protection of human health. Preliminary analyses indicate that human health risk as indicated by exposure to waterborne E. coli is predominantly driven by as little as 1% human sources, even when the contribution of wildlife and livestock waste to the E. coli load is much higher. These results of these analyses will allow watershed coordinators to better explain to stakeholders the varying importance of practices for controlling discharges of waste into impaired waterbodies, with human sources such as malfunctioning septic systems and non-compliant wastewater treatment plants receiving higher priority than control of wildlife waste as human health risks from exposure to human wastes are greater than the risks from exposure to livestock or wildlife waste. Additionally, the EPA and Texas Commission on Environmental Quality are considering adopting new guidelines for utilizing QMRA assessments integrated with BST results to offer an alternative to the development of relatively costly Recreational Use Attainability Analyses (RUAAs) for the creation of site-specific water quality standards where appropriate. These preliminary results establish a foundation for improving our understanding of the potential contribution of E. coli from various sources of differing pathogenicity and clearly demonstrate the need for further investigation. Future results also will contribute to the development of best management practices and other strategies appropriate for addressing E. coli loads to Texas watersheds.