Estuarine habitat quality reflects urbanization at large spatial scales in South Carolina's coastal zone

Land cover patterns were evaluated in 29 estuarine watersheds of South Carolina to determine relationships between urban/suburban development and estuarine habitat quality. Principal components analysis and Pearson product moment correlation analyses were used to examine the relationships between ten land cover categories and selected measures of nutrient or bacterial enrichment in the water column and contaminant enrichment in sediments. These analyses indicated strong relationships between land cover categories representing upland development and a composite measure of 24 inorganic and organic contaminants using the Effect Range Median-Quotient (ERM-Q). Similar relationships also were observed for the summed concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, and metals. Data obtained from tidal creeks generally showed stronger correlations between urban/suburban land use and pesticides and metals compared to data obtained from larger open water habitats. Correlations between PAH concentrations and the urban/suburban land cover categories were similar between creek and open water habitats. PCB concentrations generally showed very little relationship to any of the land cover categories. Measures of nutrient enrichment, which included total Kjeldahl nitrogen (TKN), nitrate-nitrite, phosphorus, chlorophyll-a, and total organic carbon, were generally not significantly correlated with any land cover categories, whereas fecal coliform bacteria were significantly and positively correlated with the urban/suburban land cover categories and negatively correlated with the non-urban land cover categories. Fecal coliform correlations were stronger using data from the open water sites than from the tidal creek sites. Both ERM-Q and fecal coliform concentrations were much greater and more pervasive in watersheds with relatively high (>50%) urban/suburban cover compared to watersheds with low (<30%) urban/suburban cover. These analyses support the hypotheses that estuarine habitat quality reflects upland development patterns at large spatial scales, and that upland urbanization can result in increased risk of biological degradation and reduced safe human use of South Carolina's coastal resources.     

Water quality before and after deep tunnel operation in Milwaukee, Wisconsin.

The mitigative effects of the deep tunnel for temporary storage of storm water and sewage, on the water quality of the Milwaukee, Menomonee, and Kinnickinnic Rivers are investigated. The analysis is based on data from the Milwaukee Metropolitan Sewerage District's overflow and surface-water quality monitoring program. Statistical analysis of water quality parameters (BOD, phosphorus, suspended solid, fecal coliform counts, zinc, and chloride) in the three rivers indicates that Menomonee River benefits the most from the deep tunnel. Fecal coliform counts inside the CSO area, and to a certain extent BOD and zinc levels, exhibit the most significant decline after 1994 when the tunnel came on line. These conclusions are based on t-test comparisons of regional averages incorporating spatial and temporal correlations from 1991 to 1993 and 1994 to 1997. The results from t-tests are complemented and confirmed with results from Mann-Kendall tests for trend. Suspended solids and chloride do not decrease after 1994.     

Sustainability of Scottish water quality in the early 21st century

This paper reviews some of the current water quality issues relating to the surface waters of Scotland and highlights some of the key issues likely to be significant over the next decade. The sustainable management of water quality requires an appreciation of the temporal and spatial assessment of the resource, together with an identification of reference or natural conditions from which to determine change, and the elucidation of the drivers of change. Only through this integrated approach, can appropriate management strategies be developed and prioritised, bearing in mind that impacts may be decoupled from sources in both time and space. This paper highlights recent trends in water quality (from a hydrochemical perspective) with separation into three broad groups: rivers, lochs and estuaries. For rivers, a general reduction in concentration of determinants that are more indicative of urban point sources (phosphorus, ammonium, suspended solids, biochemical oxygen demand etc.) is apparent, while in more agriculturally-dominated areas, an increase in concentration of solutes that are considered more diffuse in origin, (e.g. nitrate) is reported. The increasing contribution to total loads from diffuse pollutants is a priority area for both research and policy. Current scientific challenges are to define the most appropriate spatial context within which regional water quality issues can be monitored and managed. It is likely that future emphasis will be placed on making an initial ecoregion based grouping in conjunction with physically defined catchment, which will be used to quantify site-specific impacts. Such an organisational approach will provide a mechanism that enables a targeted monitoring strategy to be developed. This will allow the establishment of ecologically based targets for water quality, and an improved understanding the biogeochemistry of pollution reversibility and ecosystem recovery. It is also fundamental to the development of tools through which to predict the time scale and magnitude of any recovery, such that environmental benefit can be optimised against realistic socio-economic constraints. The inter-relations between water quality objectives and the development of legislation for water resources management in Europe are discussed.     

A model for predicting chloride concentrations in river water in a relatively unpolluted catchment in north-east Scotland

The River Dee is an oligotrophic soft water system, in the NE of Scotland, with a catchment area of approximately 2100 km2. The river rises in the Cairngorm Mountains and enters the North Sea at Aberdeen, approximately 140 km from its source. Water chemical quality data was collected every 2 weeks over 12 months for 59 sites distributed throughout the catchment. River water chloride concentrations increased significantly from west to east. In depth investigation of the relationship with distance from the coast revealed the significant difference in spatial distribution of river water chloride concentrations between upland and lowland/agricultural areas, suggesting the possible importance of agricultural practices to streamwater chloride concentrations. Thirty of the sample sites are independent and have been used to develop a simple model for prediction of streamwater Cl- concentration throughout the catchment. The model has been validated using data from the remaining sub-catchments. The model shows that mean Cl- concentration may be reliably predicted from distance from the coast and the percentage of improved grassland and arable land cover in each sub-catchment (r2 = 0.98). It is postulated that the land use effects may be partly due to the evolved link between landuse and catchment altitude characteristics, rather than just the direct effect of applied potassium chloride fertiliser on agricultural land. It was noted that there was insufficient forestry within the River Dee Catchment to reliably include % forest cover in the model.     

Comparative study of the physico-chemical parameters of the coastal waters in rivers Matla and Saptamukhi: Impacts of coastal water coastal pollution

A qualitative and quantitative research has been performed on the physico-chemical parameters of the neighboring coastal waters of the rivers Matla and Saptamukhi in the Sunderban district, West Bengal. The distribution pattern of eight physico-chemical parameters, namely pH, salinity, dissolved oxygen, suspended solids, nitrogen and phosphorus concentrations (inorganic and total) has been graphed and compared for the two rivers over a time period of ten years (??90s decade). A statistical analysis has been carried out and the correlation data between these parameters has been rationalized based on both natural and man-made activities during that time. This has pointed to various causes behind coastal pollution of river waters. The changes in water quality have been related to flood impacts, storm surge, eutrophication, domestic sewage, agricultural and industrial wastes. In order to avoid coastal degradation and maintain environmental balance, it is very important to understand the impact of these parameters on coastal zones.     

Dissolved-Oxygen/Suspended-Solids Concentration Relationships in the Upper Humber Estuary

Results of dissolved-oxygen concentration from continuous monitors at one location on the (Yorkshire) tidal Ouse and two locations on the tidal Trent have revealed a strong dependence upon the concentration of suspended sediment. High concentrations of sediment lead to a lowering in dissolved-oxygen levels. A comparison of this effect between the two rivers reveals lower dissolved-oxygen concentrations in the River Ouse than in the River Trent for a given concentration of suspended sediment, which is partly due to a difference in the quality and quantity of pollutant discharges into the Ouse compared with the Trent. Because the concentration of suspended solids at a given location is known to be dependent upon the fresh-water flow and the tidal range, it is concluded that the dissolved-oxygen concentration is also strongly dependent upon conditions of fresh-water flow and tidal range for these two tidal rivers.     

Intra-event variability of Escherichia coli and total suspended solids in urban stormwater runoff

Sediment levels are important for environmental health risk assessments of surface water bodies, while faecal pollution can introduce significant public health risks for users of these systems. Urban stormwater is one of the largest sources of contaminants to surface waters, yet the fate and transport of these contaminants (especially those microbiological) have received little attention in the literature. Stormwater runoff from five urbanized catchments were monitored for pathogen indicator bacteria and total suspended solids in two developed countries. Multiple discrete samples were collected during each storm event, allowing an analysis of intra-event characteristics such as initial concentration, peak concentration, maximum rate of change, and relative confidence interval. The data suggest that a catchment’s area influences pollutant characteristics, as larger catchments have more complex stormwater infrastructure and more variable pollutant sources. The variability of total suspended solids for many characteristics was similar to Escherichia coli, indicating that the variability of E. coli may not be substantially higher than that of other pollutants as initially speculated. Further, variations in E. coli appeared to be more commonly correlated to antecedent climate, while total suspended solids were more highly correlated to rainfall/runoff characteristics. This emphasizes the importance of climate on microbial persistence and die off in urban systems. Discrete intra-event concentrations of total suspended solids and, to a lesser extent E. coli, were correlated to flow, velocity, and rainfall intensity (adjusted by time of concentrations). Concentration changes were found to be best described by adjusted rainfall intensity, as shown by other researchers. This study has resulted in an increased understanding of the magnitude of intra-event variations of total suspended solids and E. coli and what physical and climatic parameters influence these variations.     

Simulating the impacts of future land use and climate changes on surface water quality in the Des Plaines River watershed, Chicago Metropolitan Statistical Area, Illinois

Modeling the effects of past and current land use composition and climatic patterns on surface water quality provides valuable information for environmental and land planning. This study predicts the future impacts of urban land use and climate changes on surface water quality within Des Plaines River watershed, Illinois, between 2010 and 2030. Land Change Modeler (LCM) was used to characterize three future land use/planning scenarios. Each scenario encourages low density residential growth, normal urban growth, and commercial growth, respectively. Future climate patterns examined include the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenario (SRES) B1 and A1B groups. The Soil and Water Assessment Tool (SWAT) was employed to estimate total suspended solids and phosphorus concentration generated at a 10 year interval. The predicted results indicate that for a large portion of the watershed, the concentration of total suspended solids (TSS) would be higher under B1 and A1B climate scenarios during late winter and early spring compared to the same period in 2010; while the summer period largely demonstrates a reverse trend. Model results further suggest that by 2020, phosphorus concentration would be higher during the summer under B1 climate scenario compared to 2010, and is expected to wane by 2030. The projected phosphorus concentrations during the late winter and early spring periods vary across climate and land use scenarios. The analysis also denotes that middle and high density residential development can reduce excess TSS concentration, while the establishment of dense commercial and industrial development might help ameliorate high phosphorus levels. The combined land use and climate change analysis revealed land use development schemes that can be adopted to mitigate potential future water quality impairment. This research provides important insights into possible adverse consequences on surface water quality and resources under certain climate change and land use scenarios.     

Methylmercury in rivers draining cultivated watersheds

Total mercury (THg) concentrations in streams draining cultivated watersheds in Minnesota, USA are strongly correlated with total suspended sediment (TSS) concentrations, varying widely in response to precipitation-driven inputs of soil-derived suspended sediments. Methylmercury (MeHg) concentrations in these waterways have not been studied, and little is known about mercury uptake mechanisms in resident fish populations. To begin to identify factors influencing MeHg concentrations and loadings in these streams, we measured THg and MeHg concentrations in unfiltered whole water samples from the Minnesota River and two of its major tributaries, the Blue Earth and Le Sueur Rivers. Land use in the watersheds of these rivers is over 90% row-crop agriculture, and extensive artificial drainage systems deliver runoff and associated solids quickly to local streams and rivers. THg concentrations were elevated (>10 ng/l) during much of Spring 2000 and part of the summer when runoff from precipitation events increased stream discharge and carried soil materials into the streams. Reduced precipitation resulted in low flow conditions from August through October, and THg concentrations decreased to <4.0 ng/l in all three rivers. MeHg concentrations in the Le Sueur River ranged from 0.07 to 0.42 ng/l between June and December. Higher MeHg concentrations (>0.2 ng/l) were measured during summer months when THg and TSS concentrations were high after precipitation events. Elevated MeHg concentrations were also observed in late October after leaf litter inputs. Conditions on the Blue Earth River were different, with elevated MeHg concentrations (>0.5 ng/l) observed during low flow in August and September. These higher concentrations coincided with a period of enhanced microbial growth stimulated by high late-summer temperatures. A late-October increase in MeHg concentration attributed to leaf litter inputs was also observed in this river. MeHg concentration trends in the Minnesota River were similar to those in the Blue Earth River. Indicators of biological productivity (chlorophyll a, volatile suspended solids, and total Kjeldahl nitrogen) were higher in the Blue Earth and Minnesota Rivers compared to the Le Sueur River, which may signal a connection between higher biological activity and increased MeHg concentrations.     

Storm water quality of first flush urban runoff in relation to different traffic characteristics

Storm water quality was monitored at four sites in a middle-sized Swedish town. The objective was to compare storm water pollution in the first flush storm water runoff between sites with different traffic intensities within a town. Flow proportional storm water runoff samples were collected. The samples were analyzed for suspended solids, conductivity, total nitrogen, total phosphorus, oil index, lead, cadmium, copper, chromium, nickel, and zinc.

The results showed that the levels of heavy metals and total phosphorus in storm water were highest at the site with the highest traffic intensity (7000 vehicles/day). A strong linear dependence between suspended solids (SS) and total phosphorus and heavy metals was observed. SS was the dominant explanatory variable for these parameters and a suitable predictor. The observed correlation between SS, heavy metals, and total phosphorus means that reducing levels of suspended solids in storm water would contribute to a substantial decrease of particle-bound heavy metals and total phosphorus in storm water. No samples were taken during winter; however, results indicate that de-icing material used in winter may affect surface runoff quality during other seasons. The results can be used as a reference for storm water quality management for traffic-related sites in towns with similar land use and climatic characteristics.     

Catchment characteristics controlling the mobilization and potential toxicity of aluminium fractions in the catchment of the River Dee, northeast Scotland.

Elevated streamwater concentrations of aluminium have been associated with the onset of acidification, both by natural and anthropogenic means. This has important implications for river water quality. Concentrations of total, labile-inorganic and non-labile-organic fractions of aluminium were determined across the River Dee catchment, northeast Scotland. Fifty-nine subcatchments, chosen to reflect the variety of soils, parent materials and land use patterns across this major river system were sampled bi-weekly for 1 year. The distribution of aluminium was closely linked to factors of parent material and organic soil cover. Strong spatial and temporal relationships were observed between pH and all fractions of aluminium. Significant episodic peaks in aluminium occurred, these being especially pronounced when a storm event followed a period of dry weather. A weathering rate index utilizing the Na dominance of base cations was found to be a predictor of potential streamwater toxicity implied through Ca/inorganic aluminium ratios. It was demonstrated that Al was mobilized from acid headwater streams, whilst concentrations in the main stem remained much lower.     

Estimation of suspended sediment concentrations using Terra MODIS: An example from the Lower Yangtze River, China

Traditional measurements of suspended sediment concentrations (SSC) through in-situ sampling in rivers are expensive and time-consuming to perform. Thus, these methods cannot provide continuous SSC records. Although remote sensing has been used for SSC estimation, little research has been undertaken on inland rivers, especially for highly turbid rivers like the Yangtze. Previous studies have proposed Landsat TM/ETM+ Band 4 as a spectral SSC indicator for the Yangtze, but its limitation on temporal resolution is insufficient for the study of dynamic changes of sediment. This paper presents a method of estimating SSC of the Yangtze at Jiujiang using time-series satellite data of high temporal resolution Terra MODIS. It was found that differences in water reflectance between Band 2 and Band 5 could provide relatively accurate SSC estimation even when in-situ atmospheric conditions were unknown. After cross-validation, mean absolute relative error (ARE) and relative root mean square error (RRMSE) were relatively low (i.e., 25.5% and 36.5%, respectively). This empirical relationship was successfully applied to the estimation of SSC at Datong in the Lower Yangtze River, although the SSC values were generally underestimated. This study suggests that Terra MODIS could be used to estimate SSC in large turbid rivers, although some influencing factors require further study to improve the accuracy of SSC estimation.     

Retrieval of suspended particulate matter concentrations in the Danube River from Landsat ETM data

Alternations in river channel morphology result in a disturbed natural transport of suspended particulate matter (SPM). Suspended particulate matter serves as a transport medium for various pollutants, e.g. heavy metals. It is therefore important to understand how artificial obstructions alter the natural transport of suspended matter. Measurements of SPM in rivers are traditionally carried out during in situ sampling campaigns, which can provide only a limited view of the actual spatial distribution of suspended matter over large distances. Several authors have studied how space-borne remote sensing could be used for mapping of water quality in standing waters, but with only little attention paid to rivers. This paper describes the methodology how a Landsat ETM image was used to map the spatial patterns of SPM in the Slovak portion of the Danube River. Results of our investigation reveal that the Danube River in Slovakia exhibits gradual longitudinal decrease in concentrations of SPM. Based on a strong relationship between the Landsat near-infrared band (TM4) and field measurements, we developed a map of suspended particulate matter in the Danube River with a standard error (SE) of 2.92 mg/L. This study aims to show how archived satellite data and historical water quality data can be used for monitoring of SPM in large rivers. A methodology describing the minimum samples required for sufficiently accurate results is discussed in this paper also.     

River sediments provide a link between catchment pressures and ecological status in a mixed land use Scottish River system

This study evaluates water quality, suspended and bed sediment, ecological and catchment land use data for 13 catchments of the mixed land use River Dee, NE Scotland, where pollution point sources are limited. Samples were collected at key times of biological activity (early and late summers). Mean river water concentrations were smaller in main stem and upland sites and greater in tributaries where agricultural pressures were greater and were 2-41 microgPO(4)-Pl(-1), 8-58 microg total dissolved Pl(-1) and 1-6 mg l(-1) of suspended particulate matter (SPM). SPM was 7-372 times enriched in biologically available P (BAP; determined using an FeO paper strip method) and 2-122 times in organic C relative to bed sediments. Ratios in river water concentrations of BAP attributed to the SPM (0.1-1.0 microgPl(-1)) to PO(4)-P had the greatest range at baseflow (0.01-0.80) with larger values for low land use intensity catchments. During May chlorophyll a concentrations were related to SPM BAP (p<0.001), but later in summer to PO(4)-P, and there was a corresponding change in the organic composition of SPM observed by IR spectroscopy. SPM concentrations and SPM BAP were better related to intensive grassland land use (p<0.001) than was PO(4)-P concentration (p<0.01) and also predicted abundances of filter feeding macroinvertebrates (p<0.001). Within this river system SPM quantity and composition proved to be an indicator of river biogeochemical functioning and requires further investigation as a potentially sensitive monitoring tool and to increase our understanding of chemical ecological links.     

Post-reclamation water quality trend in a Mid-Appalachian watershed of abandoned mine lands

Abandoned mine land (AML) is one of the legacies of historic mining activities, causing a wide range of environmental problems worldwide. A stream monitoring study was conducted for a period of 7 years to evaluate the water quality trend in a Mid-Appalachian watershed, which was heavily impacted by past coal mining and subsequently reclaimed by reforestation and revegetation. GIS tools and multivariate statistical analyses were applied to characterize land cover, to assess temporal trends of the stream conditions, and to examine the linkages between water quality and land cover. In the entire watershed, 15.8% of the land was designated as AML reclaimed by reforestation (4.9%) and revegetation (10.8%). Statistic analysis revealed sub-watersheds with similar land cover (i.e. percentage of reclaimed AML) had similar water quality and all tested water quality variables were significantly related to land cover. Based on the assessment of water quality, acid mine drainage was still the dominant factor leading to the overall poor water quality (low pH, high sulfate and metals) in the watershed after reclamation was completed more than 20 years ago. Nevertheless, statistically significant improvement trends were observed for the mine drainage-related water quality variables (except pH) in the reclaimed AML watershed. The lack of pH improvement in the watershed might be related to metal precipitation and poor buffering capacity of the impacted streams. Furthermore, water quality improvement was more evident in the sub-watersheds which were heavily impacted by past mining activities and reclaimed by reforestation, indicating good reclamation practice had positive impact on water quality over time.     

Long-term changes in quality of discharge water from abandoned underground coal mines in Uniontown Syncline, Fayette County, PA, USA

Changes in water quality over 25 years have been documented for discharges from an extensive network of abandoned underground coal mines in the Uniontown Syncline, Fayette County, PA, USA. A baseline study of 136 mine discharges in the syncline was conducted in 1974-1975. In 1998-2000, follow-up water flow and quality monitoring was conducted at 21 selected discharges for 2 years to assess the degree of mine water-quality improvement since 1974-1975. The data from the two periods of time were compared, with consideration of differences in measurement methods. The degree and rate of water-quality improvement was found to be highly dependent on the amount and duration of flooding in the mine voids. Water quality of discharges from the substantially flooded mine voids improved significantly, going from acidic water with high sulfate and iron concentrations in 1974-1975 to alkaline water with substantially lower sulfate and iron concentrations in 1998-2000. In contrast, the water quality in the unflooded mines showed less improvement over the 25 years between studies. The water discharging from the unflooded mines in 1974-1975 was acidic with high sulfate concentrations and in 1998-2000 was still acidic but showed somewhat lower sulfate and iron concentrations, reflecting depletion of readily available pyrite. The data obtained provide insight into the potential and rate of natural amelioration of mine water quality in different abandoned underground coal mine systems.     

Modeling copper partitioning in surface waters

Suspended particulate matter from the surface waters of the Susquehanna, Christina and Brandywine Rivers was collected by tangential flow filtration to study copper partitioning. Copper adsorption increased with an increase of suspended particles and decreased with low pH values or with an increase of dissolved organic matter. Effects of particulate organic matter on copper distribution between suspended particulate and solution phases were studied using modified aluminum oxide. An increase of particulate organic matter enhanced copper adsorption. Copper adsorption per mass of particulate organic carbon was similar for the different sources of suspended particles. A model, based on copper adsorption on particles and complexation with dissolved organic matter, was developed to assess copper partition coefficient as a function of the easily measurable water quality parameters: pH, alkalinity, dissolved organic carbon and particulate organic matter. The partitioning model was calibrated on pH edge data using suspended particles collected from the three rivers. The model was verified using partitioning data as a function of dissolved organic matter. The model adequately describes the system containing natural suspended solids collected from the surface waters.     

The strategic significance of wastewater sources to pollutant phosphorus levels in English rivers and to environmental management for rural, agricultural and urban catchments

The relationship between soluble and particulate phosphorus was examined for 9 major UK rivers including 26 major tributaries and 68 monitoring points, covering wide-ranging rural and agricultural/urban impacted systems with catchment areas varying from 1 to 6000 km² scales. Phosphorus concentrations in Soluble Reactive (SRP), Total Dissolved (TDP), Total (TP), Dissolved Hydrolysable (DHP) and Particulate (PP) forms correlated with effluent markers (sodium and boron) and SRP was generally dominant signifying the importance of sewage sources. Low flows were particularly enriched in SRP, TDP and TP for average SRP > 100 μg/l indicating low effluent dilution. At particularly low average concentrations, SRP increased with flow but effluent sources were still implicated as the effluent markers (boron in particular) increased likewise. For rural areas, DHP had proportionately high concentrations and SRP + DHP concentrations could exceed environmental thresholds currently set for SRP. Given DHP has a high bioavailability the environmental implications need further consideration. PP concentrations were generally highest at high flows but PP in the suspended solids was generally at its lowest and in general PP correlated with particulate organic carbon and more so than the suspended sediment in total.Separation of pollutant inputs solely between effluent and diffuse (agriculture) components is misleading, as part of the “diffuse” term comprises effluents flushed from the catchments during high flow. Effluent sources of phosphorus supplied directly or indirectly to the river coupled with within-river interactions between water/sediment/biota largely determine pollutant levels.The study flags the fundamental need of placing direct and indirect effluent sources and contaminated storage with interchange to/from the river at the focus for remediation strategies for UK rivers in relation to eutrophication and the WFD.     

Evaluating eutrophication potential from river community productivity

Measurements of dissolved oxygen, temperature and solar radiation were used to estimate net community production (P-R), respiration (R), gross production (P), and the P:R ratio for six rivers during the summer of 1974. Analysis of these data and comparison with a subjective ranking of the “eutrophy” of the rivers based on nutrient and chlorophyll data showed that productivity measurements in streams can be used to evaluate eutrophication potential. No single parameter or index proved reliable, but a discriminant analysis suggested that the use of respiration and the P:R ratio in conjunction can be useful. Also, the degree of temporal variability of community metabolism was a consistently good indicator of water quality. The analyses suggest that the eutrophication potential of an “unknown” river can be determined by comparing several weeks of productivity data for summer, low-flow conditions with the data presented here.     

Land-use based stormwater pollutant load estimation and monitoring system design

Accurate quantification of the amount, quality and sources of urban stormwater runoff are a prerequisite for effective stormwater management. The goal of this study was to estimate city-scale stormwater pollutant export, examine the effect of data sources on export estimates, and develop an optimization method for stormwater monitoring. The results were presented for the city of Lahti in southern Finland, where site mean pollutant concentrations (SMCs), annual pollutant loads, and monitoring guidelines for specific land use types were determined for total suspended solids (TSS), nutrients (total nitrogen TN and total phosphorus TP), chemical oxygen demand (COD), and metals (Pb, Zn, Cu, Cr, and Ni). Depending on the data source, differences between estimated pollutant exports ranged from -89% to 215%. Lack of reference data for every urban land use type and differences in land use classification schemes were identified as key factors limiting the accuracy of pollutant load estimation.