Water Quality Criteria Research Articles

Ecosystem complexity explains the scale-dependence of ammonia toxicity on macroinvertebrates

The toxic effect of unionized ammonia (NH3) on aquatic organisms is receiving increasing attention due to the excessive nitrogen discharge to various surface waters. Researches have suggested the scale-dependence of NH3 toxicity, being lower in field than under lab conditions. Such scale-dependence of toxicity is a big challenge to water quality criteria setting as the results solely from lab tests might not apply to natural ecosystems. Therefore, it is necessary to explore the underlying mechanism to understand the difference of toxicity across various spatial scales. In this study, we used the widely distributed gastropod Bellamya aeruginosa as the test animal and performed two 192-h microcosm experiments. Each experiment included a control and an ammonia addition treatment: N0(LC50) & N+(LC50), N0(LC100) & N+(LC100) (96-h LC50 = 0.8 mg NH3N/L, 96-h LC100 = 18.1 mg NH3N/L). Besides water-only, three potential key components (food, sediment, and submersed macrophytes) were included in the various treatments to mimic different complexity levels of aquatic ecosystems (Water, Water + Food, Water + Sediment, Water + Sediment + Macrophytes). The results showed that: 1) food directly improved the survival and growth of gastropods under expected lethal concentration of ammonia (96-h concentration of NH3N = LC20 of the 96-h acute test); 2) sediment and macrophyte quickly decreased the ammonia concentration, mainly by sediment adsorption and macrophyte uptake, to alleviate the ammonia stress to gastropods and permitted them to survive and grow under expected lethal concentration of ammonia (96-h concentration of NH3N = LC10∼LC20 of the 96-h acute test); 3) sediment and macrophyte also provided additional food for gastropods; 4) under extremely high ammonia stress (i.e., 96-h LC100, food was left uneaten and macrophyte died, and gastropods could, therefore, not be released from ammonia stress. Our results demonstrate that under moderate ammonia stress, the introduction of extra ecosystem elements (food, sediment, and macrophytes) significantly improved the survival and growth of gastropods, mainly by enhancing their tolerance and by quickly decreasing the NH3 concentration and thus toxicity. However, these introduced elements had little effect at very high concentration of ammonia (i.e., 96-h LC100). Our findings add to the understanding of the reasons behind the previous observed scale-dependent toxicity of NH3 on aquatic organisms and contribute to better decisions on the role of NH3 in relation to water quality management.

Water quality criteria and ecological risk assessment of lead (Pb) in China considering the total hardness of surface water: A national-scale study

Site-specific water quality criteria considering hydrochemical conditions are needed for zoning control of environmental risks. However, the differences in water quality parameters between regions have not been fully considered in the current research on water quality criteria and risk assessment of lead. In this study, lead concentration and total hardness (TH) data of surface water in 13 major river basins and 31 administrative regions in China were collected. Based on the normalization of the TH of the toxicity data, the short-term and long-term water quality criteria of lead in China's surface water in the specific TH condition (100 mg/L) were derived using the species sensitivity distribution method, which were 90.7 μg/L and 2.1 μg/L, respectively. Furthermore, this study provided general derivation formulas for the water quality criteria based on the TH of surface water and obtained the site-specific criteria for different regions/basins in China. On this basis, an ecological risk assessment considering the TH was proposed for the first time. The results showed that there was a clear risk of lead in the Pearl River Basin and the rivers in Zhejiang-Fujian. The southern coastal provinces were at an unacceptable risk level, although the lead concentrations in the surface water were medium; the opposite was true in northern China, which meant that a high concentration of lead did not necessarily pose a high ecological risk and about 25 % of the variation in the predicted risk can be explained by the TH in Monte Carlo simulation.

Using Structured Decision Making to Evaluate Wetland Restoration Opportunities in the Chesapeake Bay Watershed

Wetland restoration is an important water quality and climate resilience strategy. Wetland restoration rarely considers tradeoffs at large spatial and temporal scales, which limits capacity to aid decision makers. High resolution data can reveal hundreds to thousands of possible restoration options across a landscape, but guidance for setting restoration targets at these scales is limited. This study uses structured decision making (SDM) as a process for evaluating the desirability of numerous restoration options, with a case study on the Outer Coastal Plain of the Chesapeake Bay watershed, USA. The Nature Conservancy, in partnership with federal, state, and nonprofit organizations, evaluated a decision to target large-scale wetland restoration based on two fundamental objectives: improve water quality and enhance climate resilience. A total of 964 potentially restorable alternatives were delineated across the study area. The alternatives were evaluated on seven water quality and climate resilience criteria. High-priority alternatives were mapped based on multi-criteria ranking methods and principal component analysis. Sensitivity analysis included varying nutrient load data, implementing multiple ranking methods with different assumptions, and varying criteria weights. The maps revealed seven distinct regions of restoration opportunities. Tradeoffs were evaluated to distinguish between desirable and less desirable regions. Results indicated that three regions were promising choices to initiate landowner engagement and outreach. This study highlights the advantages of SDM to structure large-scale restoration decisions. In doing so, our work offers a roadmap toward further developing SDM in future applied restoration contexts.

Assessment of potential ecological risk of bisphenol A in surface waters via evaluation of alternative non-animal approaches

Recently, national regulatory agencies have announced plans to move away from animal testing through the adoption of new approach methods (NAMs) including in silico and in vitro approaches. In this study, we suggest a new approach of environmental risk assessment method for water quality criteria of bisphenol A (BPA) in the surface water of 11 rivers in Asia using an alternative toxicity method based on the in vitro-based cytotoxicity and genetic toxicity. The hazardous concentrations for 5% (HC5) were obtained from the species sensitivity distribution (SSD) curves based on the traditional acute toxicities (TAT), traditional chronic toxicities (TCT), and alterative acute toxicities (AAT) data. The HC5 values for the TAT, TCT, and AAT data were 2019.3 µg/L, 0.92 µg/L, and 0.68 µg/L, respectively. The TAT-based predicted no-effect concentration (PNECTAT), TCT-based PNEC (PNECTCT), and AAT-based PNEC (PNECAAT) values were derived as 1009.65 µg/L, 0.46 µg/L, and 0.34 µg/L, respectively. The TAT-based risk quotient (RQTAT) value of BPA was negligible (<0.1). The AAT-based RQ value (RQAAT) of BPA in Liuxi river (RQAAT = 21.94) of China showed the highest potential ecological risk of the 11 sampled rivers of Asia. In Korea, the highest potential risk assessment (RQAAT = 2.93) was recorded in Gyeonggi-do as the largest administrative region. The results may suggest that the application of AAT in the ecological risk assessment for surface water can replace the previously applied TCT approach.

A Novel Approach to Developing Thresholds for Total Dissolved Solids Using Standardized and Experimental Toxicity Test Methods.

The increasing salinization of freshwater streams from anthropogenic land uses and activities is a growing global environmental problem. Increases in individual ions (such as sodium or chloride) and combined measures such as total dissolved solids (TDS) threaten drinking water supplies, agricultural and economic interests, and the ecological health of freshwater streams. Because the toxicity of high ionic strength waters depends on the specific ion composition, few water quality standards exist to protect freshwater streams from salinization. In the present study, we used a novel approach to develop site-specific and ecologically relevant TDS thresholds for the protection of aquatic life. The first step of the approach was to characterize the ion composition of the waterbody or region of interest and prepare artificial samples to match that composition. Using a combination of standardized toxicity test species and more ecologically relevant field-collected species, toxicity tests were then conducted on these artificial samples prepared at a range of TDS concentrations. The advantage of this approach is that water quality criteria can be developed for easy-to-measure generalized parameters such as TDS while ensuring that the criteria are protective of instream aquatic life and account for the complex interactions of the various ions contributing to salinization. We tested this approach in Sand Branch, Loudoun County, Virginia, USA, where salinization from hard rock mining and urban runoff has impaired aquatic life. Acute and chronic TDS thresholds of 938 and 463 mg/L, respectively, were developed in this stream and used for total maximum daily load development in the watershed. The approach provides a potential model for establishing protective thresholds for other waterbodies impacted by salinization. Environ Toxicol Chem 2022;41:2782-2796. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Ambient water quality criteria derived using probabilistic risk assessment.

National recommendations for numeric human health ambient water quality criteria (AWQC) for toxic substances are derived by the US Environmental Protection Agency (USEPA) using a deterministic approach that combines point estimates for exposure, toxicity, and acceptable risk. In accordance with the Clean Water Act, states, territories, and authorized tribes must either adopt these recommendations or modify and replace them with criteria using an alternative, scientifically defensible method. Recent reports have criticized the deterministic approach, stating that it suffers from compounded conservatism by selecting upper percentiles or maximum values for multiple inputs and that it cannot directly determine what portion of the population a given criterion protects. As an alternative, probabilistic risk assessment (PRA) has been promoted as a more transparent and robust method for deriving AWQC. Probabilistic risk assessment offers several advantages over the deterministic approach. For example, PRA uses entire data distributions rather than upper-percentile point estimates to specify exposures, thereby reducing compounded conservatism. Additionally, because it links acceptable risk targets with specific segments of the exposed population, PRA-based AWQC demonstrably protects multiple subsets of the population. To date, no study has quantitatively compared deterministic and PRA approaches and resulting AWQC using national inputs consistent with USEPA guidance. This study introduces a PRA method for deriving AWQC and presents case studies to compare probabilistically derived AWQC with USEPA's 2015 recommendations. The methods and results of this work will help federal and state regulators, water quality managers, and stakeholders better understand available approaches to deriving AWQC and provide context to assumption- and method-specific differences between criteria. Integr Environ Assess Manag 2023;19:501-512.© 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Development of seawater quality criteria for phenanthrene based on toxicity data of native species in the Bohai Sea.

Phenanthrene (Phe), one of the most commonly detected polycyclic aromatic hydrocarbons, poses a potential threat to marine ecosystems due to its strong toxicity to aquatic organisms. Developing marine water quality criteria (WQC) is critical to effectively control Phe pollution. This study conducted 10 acute toxicity tests and 4 chronic toxicity tests using native species in the Bohai Sea, China and found that the half-lethal/effective concentrations (LC50/EC50) of Phe for all tested organisms were in the range of 0.198-50.142mg/L. Among them, the mysid Neomysis awatschensis was the most sensitive species, and the rotifer Brachionus plicatilis was the least sensitive. In terms of chronic toxicity, the range of no-observed-effect concentrations (NOECs) for the four tested organisms was 0.0156-4.00mg/L. Based on the toxicity data and other data collected from existing databases and literature, the established species sensitivity distribution (SSD) model revealed that the marine WQC for Phe was 39.55μg/L. Furthermore, the reliability of the derived criteria was verified by measuring multiple endpoints of Skeletonema costatum and Brachionus plicatilis after chronic exposure to Phe. Finally, the environmental concentrations of Phe in the Bohai Sea were determined to be 8.0-318ng/L, and the joint probability curve (JPC) results showed that the ecological risk of Phe was acceptable. This study provides a reference for developing seawater quality standards for Phe.

Agronomic evaluation of irrigation water on the Southern Buh and Kamianska irrigation systems

The aim of the research was to study the temporal and spatial dynamics of a set of agronomic criteria for irrigation water in the process of transporting it from the Southern Buh River intake site to the lands of the Southern Buh and Kamianska irrigation systems situated in southern Ukraine. Six stationary research sites for monitoring the quality of irrigation water were established along the route of irrigation water transportation. Determination of agronomic criteria for irrigation water quality was carried out in two terms: at the beginning of the irrigation season, in May, and at the end, in September. The content of cations of sodium, magnesium, calcium, and anions of chlorine, sulphates, carbonates, and bicarbonates was determined. In the field, the pH and electrical conductivity of water, the total salt content, and the total amount of dissolved solids were determined. It is determined that waters have an average level of danger from the point of view of salinisation of soils. This fact leads to a decrease in yield of sensitive to salinity crops (corn, alfalfa and most vegetables). The high content of sodium cations along with the low content of calcium and magnesium cations indicates the danger of degradation of the physical properties of the southern chernozems and the need to use the meliorants containing calcium. There is a high probability of toxic effects on crops caused by sodium cations. At the same time, it is stated that there is no negative effect of chlorine anions on plants.

Using Biological Responses to Monitor Freshwater Post-Spill Conditions over 3years in Blacktail Creek, North Dakota, USA.

A pipeline carrying unconventional oil and gas (OG) wastewater spilled approximately 11 million liters of wastewater into Blacktail Creek, North Dakota, USA. Flow of the mix of stream water and wastewater down the channel resulted in storage of contaminants in the hyporheic zone and along the banks, providing a long-term source of wastewater constituents to the stream. A multi-levelinvestigation was used toassessthe potential effectsofoilandbrine spillson aquatic life. In this study, we used a combination of experiments using a native fishspecies, Fathead Minnow (Pimephalespromelas), field sampling of the microbial community structure, and measures of estrogenicity. The fish investigation included in situ experiments and experiments with collected site water. Estrogenicity was measured in collected site water samples, and microbial community analyses were conducted on collected sediments. Duringthe initial post-spill investigation, February 2015, performingin situ fish bioassays was impossible because of ice conditions. However, microbial community(e.g., the presence ofmembers of theHalomonadaceae, a family that is indicativeofelevated salinity) andestrogenicitydifferences were compared to reference sitesand point toearlybiological effects of the spill. We noted water column effects on in situ fish survival 6months post-spill during June 2015. At that time, total dissolved ammonium (sum of ammonium and ammonia, TAN) was 4.41mgNH4/L with an associated NH3of 1.09mg/L, a concentration greater than the water quality criteria established to protect aquatic life. Biological measurements in the sediment defined early and long-lasting effects ofthe spill on aquatic resources. The microbial community structure wasaffected during all sampling events. Therefore, sediment may act as a sink for constituents spilled and as such provide an indication of continuedand cumulativeeffects post-spill. However, lack of later water column effects may reflect pulse hyporheic flow of ammonia from shallow ground water. Combining fish toxicological, microbial community structureandestrogenicity informationprovides a completeecologicalinvestigation that defines potential influencesof contaminantsatorganismal, population, and community levels. In general, in situ bioassays have implications for the individualsurvivalandchanges at thepopulation level, microbial community structure defines potential changes at the community level, andestrogenicitymeasurements define changes at theindividual andmolecularlevel. By understanding effects at these various levels of biological organization, natural resource managers can interpret how a course of action, especially for remediation/restoration, might affect a larger group of organisms in the system. The current work also reviews potential effects of additional constituents defined during chemistry investigations on aquatic resources.

Deriving freshwater sediment quality guidelines of polycyclic aromatic hydrocarbons using method of species sensitivity distribution and application for risk assessment

Contamination of polycyclic aromatic hydrocarbons (PAHs) in sediment has long been of great concern because of their toxic effects to benthic organisms. Sediment quality guidelines (SQGs) are the basis to evaluate the potential ecological risks of PAHs in sediments. Species sensitivity distribution (SSD) has been widely applied in deriving water quality criteria, but seldom employed in SQGs. In this study, SSD was used to derive the freshwater SQGs for four representative PAHs (naphthalene, phenanthrene, pyrene and benzo[a]pyrene) based on the sediment toxicity results. A linear relationship between the SQGs and octanol-water partition coefficient (log KOW) was developed, and applied to predict the SQGs of other twelve PAHs. The obtained SQGs were in the range of 0.46 - 1.79 mg/kg with a geometric mean of 0.97 mg/kg, which was proposed as the SQGs for total PAHs. Based on these SQGs, the risk quotients of PAHs in the sediments collected from Haihe River of China were calculated, and the toxic effects were also tested using three representative benthic organisms. As the risk quotients of the PAHs and heavy metals in the sediments were summed up, good correlations were found (p = 0.074 and 0.018) between them and the observed toxicities of the sediments. The SQGs developed for PAHs was promising in ecological risk assessment for contaminated freshwater sediments.

Optimal Site for Aquaculture Farming: An Elimination Decision Approach

One of the most important factors in determining the location of aquaculture farming is water quality. The appropriate place with the best water quality must be identified in order to grow the finest quality of fish. However, choosing the best location for aquaculture farming cannot be done only based on one factor. Instead, a number of water quality aspects, such as pH and dissolved oxygen levels, should be considered during the selection process. Thus, this study employed the Elimination and Choice Translating Reality (ELECTRE) method to rank four potential locations for aquaculture farming with five considered criteria of water quality. Three decision-makers who are professionals in aquaculture farming are invited to evaluate the rationality of the locations based on the considered criteria of water quality using real numbered linguistic terms. The process entails eight computing steps. The findings show that location A4 outperforms the other three places, proving that the Marang River is the best location for aquaculture farming.

Water quality assessment of the Karasu River (Turkey) using various indices, multivariate statistics and APCS-MLR model

Determining the water quality status of a river and accurately identifying potential pollution sources threatening the river are pillars in effective control of pollution and sustainable water management. In this study, water quality indices, multivariate statistics and absolute principal component score-multiple linear regression (APCS-MLR) were applied to evaluate the water quality of the Karasu River, the main tributary of the Euphrates River (Turkey). For this, 19 water quality variables were monitored monthly at eight stations along the river during one year. Based on the mean dissolved oxygen (DO), electrical conductivity (EC), nitrate-nitrogen (NO3–N), orthophosphate-phosphorus (PO4–P), total phosphorus (TP), ammonium-nitrogen (NH4-N), chemical oxygen demand (COD) and total nitrogen (TN) levels, most stations of the river had “very good” water status according to surface water quality criteria. Spatial cluster analysis (CA) divided eight stations into three regions as clean region, moderate clean region and very clean region. The mean values of Nutrient Pollution Index indicated that the river was “no polluted”. Similarly, Water Quality Index and Organic Pollution Index values indicated that the river water quality was between “good” and “excellent”. A minimum water quality index (WQImin) consisted of ten crucial parameters was not significantly different with the WQI based on all the 17 parameters. Discriminant analysis (DA) results showed that water temperature (WT), EC, chlorophyll-a (Chl-a), potassium (K), calcium (Ca), NO3–N and COD are the variables responsible for temporal changes, while WT, total dissolves solids (TDS), Chl-a, K, magnesium (Mg), Ca, NH4–N and COD are the variables responsible for spatial changes in the river water quality. Principal component analysis/factor analysis (PCA/FA) identified four potential sources, including anthropogenic, natural, seasonal and phytoplankton. Source apportionment in the APCS-MLR model revealed that seasonal and anthropogenic sources contributed 35.2% and 25.5% to river water quality parameters, respectively, followed by phytoplankton (21.4%) and natural sources (17.9%).

Quantifying the effects of land use change and aggregate stormwater management practices on fecal coliform dynamics in a temperate catchment.

Changes in land use and land cover (LULC) due to land development can lead to an increase in diffuse microbial pollutions and, consequently, degradation of the receiving aquatic ecosystem. However, the mechanisms underlying these phenomena are rarely considered in hydrological models. Therefore, in this study, fecal indicator bacteria (FIB) and total suspended solids (TSS) in a temperate catchment were simulated using a well-established water quality model (Personal Computer Storm Water Management Model) to systematically quantify the factors influencing their dynamics and the effects of stormwater management. Additionally, high-resolution data (e.g., water quality variables and LULC changes) were used to calibrate the model, which accurately reproduced the physical and biological features of the catchment. The results showed that increases in bare land areas and impervious cover in the catchment exceeded the Korean (as well as the USEPA-based) standard recreational water quality criteria for fecal contamination and TSS. Dissolved organic compounds (only during storm events), TSS, and total nitrogen (except during the pre-development phase) were the strongest predictors in shaping FIB dynamics. The multiple control of stormwater management reduced the FIB and TSS concentrations by approximately 65% in the catchment. The results of this study not only provide conclusions on the drivers of FIB and TSS dynamics and their quantitative contribution but also help in designing a methodology for empirical and ecological predictions of diffuse microbial and TSS pollution in a catchment with ongoing land development.

Comparison of the sensitivity between indigenous and exotic aquatic species for fluoranthene and derivation of water quality criteria (WQC).

Fluoranthene (FLU) has shown relatively high toxicity to aquatic life as a priority polycyclic aromatic hydrocarbon (PAH). Considering the toxic effects of FLU on aquatic organisms and its high detection frequency in the aquatic environment, it is necessary and critical to derive FLU water quality criteria (WQC) for the protection of aquatic organisms and ecological risk assessment. However, due to the lack of toxicity data at different classification levels, there has been no research about the WQC of FLU. In this study, nine acute and three chronic toxicity tests were carried out on 9 Chinese indigenous aquatic species from different classification levels to obtain toxicity data. According to the US EPA guidelines, the criterion maximum concentration of 0.570 mg/L and the criterion continuous concentration of 0.174 mg/L were developed. There is no significant difference when comparing the species sensitivity distributions between indigenous and exotic species. Therefore, it is possible to use toxicity data from organisms in different areas for ecological risk assessment of FLU. CAPSULE: We compared the sensitivity between indigenous and exotic aquatic species for fluoranthene and derived its water quality criteria.

Derivation of Water Quality Criteria for Carbamazepine and Ecological Risk Assessment in the Nansi Lake Basin.

Carbamazepine, as one of several pharmaceutical and personal care products, has gained much attention in recent years because of its continuous discharge in natural waters and toxicity to aquatic ecosystems. However, it is difficult to evaluate and manage carbamazepine pollution because of the lack of a rational and scientific Water Quality Criteria (WQC) of carbamazepine. In this study, the carbamazepine toxicity data of thirty-five aquatic species from eight taxonomic groups were selected, and the species sensitivity distribution (SSD) method was applied to derive the WQC for carbamazepine based on the Log-logistic model, which was 18.4 ng/L. Meanwhile, the occurrence and distribution of carbamazepine in the Nansi Lake basin was studied. Results showed that concentrations of carbamazepine in 29 sampling sites were in the range of 3.3 to 128.2 ng/L, with the mean of 17.3 ng/L. In general, the levels of carbamazepine in tributaries were higher than those in the lakes. In addition, qualitative and quantitative ecological risk assessment methods were applied to assess the adverse effect of carbamazepine on aquatic systems. The hazard quotient (HQ) method showed that there were 24 and 5 sampling sites, in which risk levels were low and moderate, respectively. The joint probability curve (JPC) method indicated that ecological risks might exist in 1.4% and 1.0% of surface water, while a 5% threshold and 1% threshold were set up to protect aquatic species, respectively. Generally, carbamazepine posed a low risk to the aquatic organisms in the Nansi Lake basin.

Quantity–quality-based water allocation programming in a reservoir–river system

Abstract Simulation–optimization approaches are useful methods for the assessment of water resource engineering plans and finding the best management policy at the watershed scale. In this study, to find the optimum operation for a reservoir with the purpose of satisfying water demands while meeting the water quantity and quality criteria, a generic reservoir and river basin simulation model (MODSIM) is coupled with the particle swarm optimization (PSO) algorithm leading to construct the PSO–MODSIM model. With the decision variables of the reservoir's monthly releases, the objective function is to maximize the supply for downstream demands while keeping the electrical conductivity (EC) in the river flow lower than a predefined level at the downstream checkpoint, which is a function of the EC in the agricultural return flows. Moreover, a safe flow rate is defined in which the streamflow should not exceed at the checkpoint resulting in mitigation of the submerging lands damage. Results obtained by the PSO–MODSIM model indicate the ability of the proposed simulation–optimization approach for solving the problem of optimal quantity–quality-based water allocation in a reservoir–river system. For instance, the EC at the checkpoint is decreased by 61% in the optimum reservoir operation state comparing the present situation, whereas the municipal and environmental demands are fully met and the agricultural demands are supplied with a desirable reliability satisfaction level.

Determination of the ecological water quality in the Orienco stream using benthic macroinvertebrates in the Northern Ecuadorian Amazon.

In recent years, pollution of watercourses in nearby protected ecosystems has increased due to urbanization. Standard physiochemical methods and probes are one way to monitor watercourses for quality. However, they often do not provide the full ecological status of the body of water. In this work, we set out to assess the ecological water quality of an urban stream by using benthic macroinvertebrates as bioindicators. We conducted the work on the Orienco stream in Lago Agrio in the province of Sucumbíos in the Northern Ecuadorian Amazon (NEA). The stream has become a sink of raw domestic sanitary wastewater from rural and urban areas. A total of 4511 macroinvertebrates from 10 families were identified across 17 sampling points. We compared our results from the biotic indices derived from the macroinvertebrates to standard water-quality parameters (temperature, conductivity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total suspended solids, ammonia-nitrogen, and pH) simultaneously sampled in the stream. The standard parameter results indicated that the water-quality levels of the stream met the Ecuadorian water-quality criteria most of the time. However, the results from the biotic indices classified the stream water as poor or very poor water quality. The results from the Biological Monitoring Working Party, Average Score per Taxon, and Family Biotic Indices had overall scores of heavily polluted waters of 45, 4.5, and 8.74, respectively. Furthermore, these results were consistent with reduced richness and evenness, and overall lower Shannon diversity and relatively higher Simpson Dominance indices of 0.71 and 2.56, respectively. We conclude that the macroinvertebrates were better indicators of the ecological water quality of the Orienco stream than the water-quality parameters from standard methods and probes alone. Our findings highlight the need for more integrated ecological assessments, which can provide critical information to the management and conservation strategies of urban watercourses in the NEA region. Integr Environ Assess Manag 2023;19:615-625. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

When it snows it pours: Increased chloride concentrations in the Cuyahoga River during the last half century

Road salt (NaCl, halite) use in areas with substantial snowfall has increased dramatically since the mid-20th century. However, few studies on chloride loading to the Laurentian Great Lakes or Ohio rivers have been conducted. To that end, we analyzed long-term (1972–2019) chloride data across 10 watersheds obtained as part of the Heidelberg Tributary Loading Program (HTLP) for the Lake Erie, Ohio River, and Grand Lake St. Marys watersheds and found that the Cuyahoga River, which has the greatest percent urban land use, had the highest watershed yield and mean concentrations of chloride for any of the HTLP rivers. Further, we apportioned the data seasonally to determine if river chloride levels were greater during seasons of road salt application (Winter) and snowmelt (Spring). Seasonally, winter levels of chloride exceeded the USEPA chronic water quality criteria concentration of 230 mg/L in more than half of the years of the 21st century, compared to only 1 year exceeding this value in the late 20th century. Further, road salt application is increasing with time in the Cuyahoga, Maumee, and Sandusky River watersheds. This increase is significantly and positively related to winter, spring, and fall mean chloride concentrations in the Cuyahoga River and winter mean chloride concentrations in the Maumee River. Finally, chloride-to-sulfate mass ratios (CSMR) for the Cuyahoga River almost always exceeded the 0.5 value that promotes corrosivity of metal pipes and are increasing with time. Ways to minimize the use of or even replace road salt as a deicer are warranted.

Determining water quality of the lower basin of the Usumacinta River in Tabasco, Mexico

Objective: The objective of this study was to determine the water quality of the lower basin of the Usumacinta River, based on its physicochemical and microbiological characteristics. Design/methodology/approach: There were taken 11 monthly samplings of surface water during the rainy season, from June to December, 2017 and in the dry season, from April to May, 2018, in three different sites. The parameters of temperature, pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), total phosphorus (TP) and Nitrogen nitrate (N-nitrate) were evaluated. Significant statistical differences (p≤0.05) between seasons and between sites were determined. Results: The results obtained were compared with Mexican regulations and Ecological Criteria for water quality. The parameters such as EC, TDS, TSS and total phosphorus showed substantial differences among seasons. The temperature, pH, EC and N-nitrate, did not exceed the maximum permissible limits for the use of irrigation water, urban public use and protection of aquatic life. However, the presence of E. coli and total coliforms from 530 to&gt; 24 196 MPN/100 ml was recorded throughout the study period. Findings/conclusions: Parameters under study did not show significant differences between sites. The rainy season had an important effect on the increase in concentrations of TSS, TP, N-nitrate and total coliforms. Also, that maximum concentrations were recorded during the study period in the sampling sites of Boca del Cerro (R1) and Puente Chablé (R2).

Use of Interspecies Correlation Estimation (ICE) Models to Derive Water Quality Criteria of Microplastics for Protecting Aquatic Organisms.

Microplastics (MPs) in the water environment pose a potential threat to aquatic organisms. The Species Sensitivity Distribution (SSD) method was used to assess the ecological risks of microplastics on aquatic organisms in this study. However, the limited toxicity data of aquatic organisms made it impossible to derive water quality criteria (WQC) for MPs and difficult to implement an accurately ecological risk assessment. To solve the data gaps, the USEPA established the interspecies correlation estimation (ICE) model, which could predict toxicity data to a wider range of aquatic organisms and could also be utilized to develop SSD and HC5 (hazardous concentration, 5th percentile). Herein, we collected the acute toxicity data of 11 aquatic species from 10 families in 5 phyla to fit the metrical-based SSDs, meanwhile generating the ICE-based-SSDs using three surrogate species (Oncorhynchus mykiss, Hyalella Azteca, and Daphnia magna), and finally compared the above SSDs, as well as the corresponding HC5. The results showed that the measured HC5 for acute MPs toxicity data was 112.3 μg/L, and ICE-based HC5 was 167.2 μg/L, which indicated there were no significant differences between HC5 derived from measured acute and ICE-based predicted values thus the ICE model was verified as a valid approach for generating SSDs with limited toxicity data and deriving WQC for MPs.