Water Quality Monitoring Data Research Articles

Factors influencing chlorophyll in an agriculturally-impacted river.

The Minnesota River (USA) drains nearly 40,000 km 2 of land in southern and western Minnesota, 92% of which is under intensive agricultural production. The river is a significant source of point and non-point source pollutant loads, including sediment, nutrients, pesticides, and pathogens. This study presents the analysis of 18 years of water quality monitoring data (approximately 50 samples per year) at a site located upstream of the major metropolitan area of Minneapolis/St. Paul. Mean monthly soluble reactive phosphorus and dissolved inorganic nitrogen values ranged from 57 to 150 μg/l and 2.82 to 7.09 mg/l, suggesting that algal nutrient limitation is not relevant in the lower Minnesota River. There is a strong negative relationship between discharge and chlorophyll a concentration during the April-to-October period (r 2 = 0.70), but this relationship did not hold during the 1988-1990 drought period. Mean monthly chlorophyll values showed a small peak in late spring, lowered values during June/July, and the highest values during the August-October period. Elevated sediment levels in June/July (> 150 mg/I) may be partially responsible for the lowered chlorophyll levels at that time, possibly due to shading and/or abrasive mechanisms. Although algae appear to be a small component (1 %) of suspended matter in the Minnesota River, algal respiration and decomposition may be contributing significantly to biochemical oxygen demand.

Spatial Extrapolation of Soil Characteristics Using Whole‐Soil Particle Size Distributions

Soils support ecosystem functions such as plant growth and water quality because of certain physical, chemical, and biological properties. These properties have been studied at different spatial scales, including point scales to satisfy basic research needs, and regional scales to satisfy monitoring needs. Recently, soil property data for the entire USA have become available in the State Soil Geographic Data Base (STATSGO), which is appropriate for regional-scale research. We analyzed and created models of STATSGO data in this study to serve as a research tool, for example, for linking the soil to regional water quality monitoring data in our companion paper. Map units in STATSGO define geographic land areas by soil characteristics (SCs) of similar soil series. We selected 27 SCs that influenced water properties (in varying degrees), aggregated the layer and component SCs to map unit SCs, and used SCs to calculate relationships among map units. The relationships were defined by equations of conditional mean for the qth SC (SCq), while using the remaining 26 SCs as predictors. The relative standard errors for 22 of the 27 SCs were less than 10%, and less than 22% for the remaining five. We conclude that spatial extrapolation of SCs is feasible and the procedures are a first step toward extrapolating information across a region using SC-water property relationships. Although our procedure is for regional scale monitoring, it is also applicable to finer spatial scales commensurate with available soil data.

Stream phosphorus transport in the Lake Tahoe basin, 1989-1996.

Lake Tahoe is undergoing the initial stages of cultural eutrophication due to human alteration of the airshed and watershed. The lake's switch from nitrogen (N) to phosphorus (P) limitation has been attributed primarily to atmospheric N loading. This places an increased importance on controlling watershed movement of P to the lake. A stream water quality monitoring data set consisting of nine streams in the Lake Tahoe basin has been analyzed to characterize the spatiotemporal variation of P delivery to the lake. This data is from the Lake Tahoe Interagency Monitoring Program (LTIMP), which provides scientific data for planning and regulatory agencies to address environmental problems in the Lake Tahoe basin. Results indicate that P delivery (concentrations, loads) varies greatly at interannual, seasonal, and spatial scales. Annual and seasonal total P (TP) concentrations can vary up to three orders of magnitude in a given stream and are strongly associated with suspended sediment. Particulate P is the major form of P transported by Tahoe streams and was strongly correlated with percent surficial geologic deposits, which are primarily located near streams. Tahoe streams with the highest annual P concentrations often had the lowest annual P loads, and visa versa. P loading is greatest during the spring snowmelt (75% of annual average). Potential watershed parameters influencing P delivery to Lake Tahoe have been identified as precipitation, basin area, basin steepness, and road and human development coverage. Results also suggest that human development impacts on stream P loads are most prevalent during high precipitation years. Identification and quantification of stream sediment and P sources such as streambanks and impervious surface is necessary to aid in watershed restoration efforts.

THE USE OF BIOLOGICAL AND WATER QUALITY MONITORING DATA FOR MANAGING NONPOINT SOURCE POLLUTION IN FULTON COUNTY, GEORGIA

THE USE OF BIOLOGICAL AND WATER QUALITY MONITORING DATA FOR MANAGING NONPOINT SOURCE POLLUTION IN FULTON COUNTY, GEORGIAFulton County is performing a watershed assessment to evaluate water quality for several watersheds in the County. Results from the Camp Creek Watershed are presented as they relate to land use, point and nonpoint source pollutant loadings, and other important watershed factors. The purpose of the watershed assessment is to develop a management plan to control nonpoint source pollution and improve...Author(s)Dale B. JonesSourceProceedings of the Water Environment FederationSubjectSession 8 - Urban Watershed Issues IDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2000ISSN1938-6478SICI1938-6478(20000101)2000:6L.569;1-DOI10.2175/193864700785150330Volume / Issue2000 / 6Content sourceWatershed ConferenceFirst / last page(s)569 - 597Copyright2000Word count511

Land use in the Taupo catchment, New Zealand

This paper describes current initiatives to develop a lake management plan for Lake Taupo, New Zealand. Recently there has been an indication that a shift from dry stock farming to large‐scale dairy farming will occur in the Taupo catchment. The local community has expressed an interest in this shift towards more intensive land use. There is public concern regarding the current state of Lake Taupo's water quality and the ability to maintain environmental quality in the face of increasing development pressures. Concerns about rising levels of nutrients in the lake are supported by trend analysis of lake water quality monitoring data. The Taupo District Council and the Waikato Regional Council have proposed development of a Lake Taupo Management Plan. A number of mechanisms for achieving this process could be explored. These include a plan largely developed by an inter‐agency management group or a more public participatory approach directly involving the community. A general lake planning framework is described and some of the limitations of the process explored. Comparison with experiences at Lake Rotorua, New Zealand, and Lake Tahoe, United States of America, supports a pre‐cautionary approach to the use of predictive ecological models in policy development. The inability of aquatic ecological theory to conform to quantitative approaches in other physical sciences needs to be acknowledged by scientists and conveyed to the public. Until the link between land‐use practice and water quality is better understood, a pre‐cautionary approach to catchment development at Lake Taupo should be encouraged. One cannot assume that common desires for both environmental protectionism, and progressive intensification of land use, will lead to sustainable resource management. The environmental effects of dairy farming indicate that encouraging this land‐use practice will not lead to the desired community expectation of water quality protection at Lake Taupo.

Localized Changes in Transparency Linked to Mud Sediment Expansion in Lake Okeechobee, Florida: Ecological and Management Implications

ABSTRACT During the last decade, water quality monitoring data have indicated declines in Secchi transparency in the southwestern pelagic region of Lake Okeechobee. Sampling stations that previously displayed intra-annual variation in Secchi depths from 0.2 to 2.7 m now display Secchi depths that never exceed 1.0 m. The historical changes in transparency occurred abruptly, and the recent low transparencies have been very stable. Ratios of Secchi/total depth indicate that light often may have reached the lake bottom (ratios > 0.5, and as high as 1.0) prior to the new stable state, but never reached the bottom afterwards (ratios <0.3). Secchi depth vs. chorophyll a relationships also have changed in the southwestern pelagic region. Stations previously displayed significant inverse log relationships between the two variables, similar to what is observed today at near-shore, sand-bottomed sites in Lake Okeechobee. In recent years, there has been no relationship between Secchi depth and chlorophyll a. This is similar to the mud-bottomed central pelagic region, where abiotic turbidity controls light attenuation. One explanation for the sudden changes in Secchi transparency is migration of mud sediments from mid-lake towards the southwestern shore. A comparison of sediment maps constructed in 1975 and 1988 indicates that the area of lake bottom covered by mud sediment increased from approximately 30 to 44% over that period. The major direction of expansion was to the southwest, and the postulated movement coincided closely with dates when Secchi declines were observed at water quality monitoring stations. The declines in transparency that have occurred in the southwest near-shore region of Lake Okeechobee may have important ecological and societal implications. This near-shore region is the primary foraging and nesting habitat for commercial and sport fish, wading birds, and migratory water fowl. Losses of submerged plant communities due to reduced light penetration may adversely affect these communities. In addition to a present goal of external P load reduction, lake managers should give consideration to in-lake methods that might prevent further water quality degradation in near-shore regions. Because water depth can act synergistically with turbidity to bring about the changes described above, one option is a substantial draw-down of the lake, followed by actions to prevent the prolonged high lake stages that recently have led to submerged plant declines. Selective dredging of sediments from the southwest region of the lake might also be considered, although this would likely be only a short-term solution to the water quality problems, given the remaining large source of mud at the center of the lake.

Using GIS for catchment management and freshwater salmon fisheries in Scotland: the DeeCAMP project

The Dee Catchment Management Planning Geographical Information System (DeeCAMP GIS) project is a partnership venture working towards integrated catchment management with a particular focus on the freshwater salmon fishery. The project uses an Arc/Info Unix-based GIS database (and user interface), incorporating topographic, geology and land use data, together with derivatives of these and other data sets, such as water-quality monitoring data and ecological field survey information. This shared database provides a useful framework for discussing, clarifying and facilitating the achievement of project objectives, whilst minimizing duplication of effort and misunderstanding. A new GIS aid for salmon managers is described and developed within the project. This illustrates how, by compiling catchment-specific data, GIS can catalyse the creation of new analytical tools that are useful for management. The GIS tool integrates stream slope and width estimates with stream locations, electrofishing survey data and local knowledge to define accessible and inaccessible stream areas for salmon in the Dee catchment, Scotland. An example data set illustrates the benefits to salmon managers (prioritizing survey effort, estimating natural spawning distribution, and identifying suitable areas for stocking with eggs or fry).

Eutrophication Dynamics of Tolo Harbour, Hong Kong

The time and spatial variation of water quality in Tolo Harbour, a eutrophic landlocked semi-enclosed bay frequented by algal blooms, is studied using a dynamic eutrophication model. Hourly changes of tide levels and currents are computed by a link-node model assuming M 2 tidal forcing. Phytoplankton growth is assumed to be limited by solar radiation, nitrogen and temperature. The model incorporates light acclimation by algae, self-shading, photosynthetic production, nutrient uptake, and a dynamic determination of the carbon to chlorophyll ratio. In particular, sediment-water-pollutant interactions are modelled via an anaerobic benthic layer segment. Using recorded pollution loads and environmental forcing as input, the model predictions of daily-averaged water quality are compared with the extensive water quality monitoring data of the Environmental Protection Department (EPD). The predicted spatial distribution and trends of algal biomass, inorganic nitrogen, dissolved oxygen (DO), as well as sediment oxygen demand (SOD), are in general agreement with field observations.

The Water Quality of Lake Taihu and Its Protection

Lake Taihu, the third largest fresh water lake in China, with a surface area of 2 338 km², is located in the Changjiang River Delta, the most advanced economic zone in China. During the last two decades, the rapid economic development of local agriculture and industry both in the urban and rural areas of the region has made great advances. Great quantieis of pollutants have been discharged into the lake, its nutrient content has increased continuously, and phytoplankton blooms have occurred in some areas. Water quality protection in Lake Taihu is very important because of its close relation with economical development and people's daily life. It is urgent to have comprehensive pollution control in Lake Taihu. Based on water quality monitoring data in Lake Taihu from 1987 to 1994, the dynamic variations of water quality and eutrophication trends have been analyzed, showing obvious spatial and temporal variations. The main water quality factors were compared with the standard for drinking water and indicate considerable change with the seasons. Some basic strategies to protect water quality and prevent eutrophication are discussed.;Lake Taihu, the third largest fresh water lake in China, with a surface area of 2 338 km², is located in the Changjiang River Delta, the most advanced economic zone in China. During the last two decades, the rapid economic development of local agriculture and industry both in the urban and rural areas of the region has made great advances. Great quantieis of pollutants have been discharged into the lake, its nutrient content has increased continuously, and phytoplankton blooms have occurred in some areas. Water quality protection in Lake Taihu is very important because of its close relation with economical development and people's daily life. It is urgent to have comprehensive pollution control in Lake Taihu. Based on water quality monitoring data in Lake Taihu from 1987 to 1994, the dynamic variations of water quality and eutrophication trends have been analyzed, showing obvious spatial and temporal variations. The main water quality factors were compared with the standard for drinking water and indicate considerable change with the seasons. Some basic strategies to protect water quality and prevent eutrophication are discussed.

The water quality of Lake Taihu and its protection

Lake Taihu, the third largest fresh water lake of China, with a surface area of 2338 km2, is located in the Changjiang River Delta, the most advanced economic zone in China. It is a typical saucer-like shallow lake in its depth and shape. During the last decade, the rapid economic development of local agriculture and industry both in the urban and rural areas of the Taihu region has made great advances. Great quantities of pollutants have been discharged into the lake, its nutrient content has increased continuously, and phytoplankton blooms have occurred in some areas. Water quality protection in Lake Taihu is very important because of its close relation with economic development and people's daily life. It is urgent to have comprehensive pollution control in Lake Taihu. Based on water quality monitoring data in Lake Taihu from 1986 to 1993, the dynamic variations of water quality and eutrophication trends have been analyzed, showing obvious spatial and temporal variations. The main water quality factors were compared with the standards for drinking water and indicate considerable change with the seasons. Basic strategies to protect water quality and prevent eutrophication are discussed.

EVALUATION OF WATER QUALITY AND MONITORING IN THE ST. LUCIE ESTUARY, FLORIDA1

ABSTRACT: The St. Lucie River and its tributaries form a major estuarine system on the southeast coast of Florida. This system is strongly affected by anthropogenic influences, including controlled releases of freshwater from Lake Okeechobee through the St. Lucie Canal and an extensive artificial drainage and irrigation system in the watershed. In the present study, three years of biweekly water quality monitoring data from the estuary were examined. The major stresses to the system stem from high variability of the salinity, frequent low dissolved oxygen (DO) events, and light limitation due to high levels of humic substances brought into the system with the fresh water. Nutrient levels also are high. Management goals for the system, including improvement of DO and water clarity, will require reduction in quantity and variability of freshwater releases.

Relating Algal Bloom Frequencies to Phosphorus Concentrations in Lake Okeechobee

ABSTRACT Empirical relationships were developed between algal bloom frequencies and total phosphorus concentrations for three distinct regions of Lake Okeechobee, and hypotheses were derived to explain observed spatial variation in those relationships. The analyses were based on water quality monitoring data collected monthly between 1986 and 1993, at 10 open-water stations, 12 north littoral stations, and 14 south littoral stations. Using a cross-tabulation procedure, phosphorus/bloom-frequency relationships were developed for bloom criteria of 10, 20, 30, 40, 50, and 60 μg L−1 chlorophyll a. For bloom criteria in the range of 40 to 60 μg L−1 chlorophyll a, blooms were not detected when phosphorus was less than 30 μg L−1, During the 1986–1993 monitoring period, this threshold phosphorus concentration was exceeded 3% of the time in the open lake, 25% of the time in die north littoral, and 48% of the time in die south littoral. When phosphorus concentrations were between 30 and 60 μg L−1 in die littoral re...

Empirical models for estimating the concentrations and exports of metals in rural rivers and streams

Concentrations of Al, Fe, Mn, Zn and Cu were measured monthly at 24 sites in 21 rivers in Ontario and Quebec. Relationships between metal and suspended particulate matter (SPM), turbidity, colour (g440), temperature and system hydrology were quantified, and used to derive empirical models for predicting metal concentrations. In a test of the models using an independent data set, they explained a significant proportion of the variation in Al (90%), Fe (85%), and Mn (57%), but only 37% of the variation in riverine Zn concentrations. Metals concentrations are most strongly associated with SPM concentrations. The proportion of the total metal load associated with particulates (>0.45 μm) is highly variable below 10 ppm SPM, indicating that this concentration approximates the division between systems dominated by weathered (solution) versus eroded (particulate) inputs. Annual metal exports were calculated, and empirical models for predicting catchment exports were developed using system hydrology and average SPM concentrations. These simple models can be used to estimate metals concentrations and exports from routine water quality monitoring data, without requiring chemical analyses. They also serve to distinguish background levels from those indicating metal contamination, and will, therefore, be useful for water quality evaluation.

Integration of long-term fish kill data with ambient water quality monitoring data and application to water quality management

Almost half (354) of all fish kills (805) in South Carolina, USA, between 1978 and 1988 occurred in the coastal zone. These kills were analyzed for causative, spatial, and temporal associations as a distinct data set and as one integrated with ambient water quality monitoring data. Estuarine kills as a result of natural causes accounted for 42.8% followed by man-induced (35.1%) and undetermined causes (22.1%).

GROUND AND SURFACE WATER QUALITY IMPACTS OF NORTH CAROLINA SANITARY LANDFILLS1

ABSTRACT: Ground and surface water quality monitoring data from 71 municipal sanitary landfills in North Carolina were analyzed to determine the nature and extent of current contamination problems and identify any common characteristics associated with this contamination. A total of 322 surface and 411 ground water quality records were analyzed using the SAS data system. Almost all the landfill records included inorganic and heavy metal analyses while approximately half of the records also included organic analyses by CC/MS.Our analysis indicates that landfills are having measurable impacts on ground and surface water quality, but these impacts may not be as severe as is commonly assumed. Statistically significant increases were detected in the average concentrations in ground water and downstream surface water samples when compared to upstream surface water samples. The largest percentage increases were observed for zinc, turbidity, total organic carbon, conductivity, total dissolved solids, and lead. Violations of ground water quality standards for heavy metals and hazardous organic compounds were detected at 53 percent of the landfills where adequate data existed. The moat common heavy metal violations were for lead (18 percent), chromium (18 percent), zinc (6 percent), cadmium (6 percent), and arsenic (6 percent) (percentage of landfills violating shown in parenthesis). The organic compounds that appear to pose the greatest threat to ground water are the chlorinated solvents (8 percent), petroleum derived hydrocarbons (8 percent), and pesticides (5 percent). A comparison of monitoring data from sanitary landfills and secondary wastewater treatment plants suggests that the concentrations of heavy metal and organic pollutants discharged to surface waters from these two sources are similar.

Waste water pollution modelling in the Southern Area of Lake Saimaa, Finland, by the SIMCA pattern recognition method

Partial least squares modelling in latent variables (PLS) is proposed for the solution of water pollution source apportionment problems. SIMCA, principal component analysis (PCA), and PLS are applied to the water quality monitoring data collected from Lake Saimaa, Finland. PCA is used to investigate the origin of the effluents and discriminant PLS is used to calculate linear mixing proportions for two waste water types and clean water at the sampling points. The PLS method is also used to estimate the time lag between discharge and sampling.

Biomonitoring of organic pollution using periphyton, South Branch, Canterbury, New Zealand

Abstract The use of periphyton to monitor the effects of organic pollution in shallow, swift New Zealand rivers was tested using a slaughterhouse effluent discharge to the South Branch, Canterbury. Eight 1 ‐week long artificial substrate accrual periods were used. A range of taxonomic and biomass determinands were analysed for during the first 2 periods. However, only chlorophyll a, ash‐free dry weight (AFDW) and their derivative the Autotrophic Index (AI), were used for subsequent monitoring as they provided the most efficient means of discriminating the effluent impacts. Intensive chemical monitoring during these first 2 sampling periods identified a highly concentrated organic waste with high daily variability (x total Kjeldahl nitrogen = 5.04 and 1.90 mg 1‐1, %CV = 74 and 79). Effluent volumes were slowly reduced over a 4‐month period. This resulted in reductions in the AI (maximum of 4377 down to 191) of downstream communities and demonstrated the benefit of effluent diversion. The community also responded to low‐level organic contamination at the control site as shown by the AI. There was a highly significant correlation (r=0.926) between biochemical oxygen demand and the AI. There were no significant differences in the AI between control and impact sites for 2 sampling periods after the effluent had been diverted from the river. It is concluded that periphyton have the potential to provide good data on the biological effects of organic discharges to shallow, swift New Zealand rivers to complement water quality monitoring data.

Land‐Use and Water Quality in Tributary Streams of Lake Tahoe, California‐Nevada

AbstractWe examined land‐use and water quality monitoring data for 10 watersheds of tributary streams to Lake Tahoe, California‐Nevada, to describe relationships between watershed disturbance and water quality degradation from nonpoint sources. Discharge‐weighted annual average concentrations of nitrate (as NO3‐N), soluble P, total P and suspended sediment were plotted against the proportion of each watershed represented as disturbed and imperviously covered land of various land‐use classes. Comparisons between land‐use and runoff water quality demonstrated significant relationships between increased coverage and disturbance in the watersheds and decreased water quality. The concentrations of NO3‐N, total P, and suspended sediment in the streams increased significantly with the disturbance of high hazard lands (erodible soils, steep slopes, stream environment zones). Increased disturbance of lower hazard lands (less erodible soils) resulted in increases in the concentrations of soluble and total P. The patterns of significance and slopes of the relationships demonstrated increased nonpoint source water quality degradation with increased land disturbance in these Sierra Nevada watersheds.

Nonpoint Pollution and Watershed Management: A Remote Sensing and Geographic Information System (GIS) Approach

ABSTRACT Dallas Water Utilities (DWU) uses Landsat multispectral remote sensing data for determining historical land use changes in watersheds and identifing critical areas where water quality protection efforts should be maximized. Water quality monitoring data are used to document actual impacts to reservoirs from areas predicted by remote sensing analyses to be adversely affected. Additionally, DWU monitors ail National Pollutant Discharge Elimination System (NPDES) and Texas Water Commission waste discharge permit applications and plant performance histories. This ensures that DWU reviews point source discharges and assists the Texas Water Commission in their monitoring functions. DWU cooperates with other area agencies to promote regional wastewater treatment as an alternative to numerous package plants which have a history of poor wastewater management. Point source management should result in lower total nutrient loads to reservoirs. Remote sensing technology provides one of the most efficient meth...

Determining the Statistical Sensitivity of the Water Quality Monitoring Program in the Taylor – Nubbin Slough, Florida Project

ABSTRACT Reducing agricultural nonpoint source (NPS) pollution by implementing best management practices (BMPs) throughout entire watersheds' is being studied in 20 Rural Clean Water Program (RCWP) projects throughout the United States. The Taylor Creek – Nubbin Slough RCWP Project area is located directly north of Lake Okeechobee in southern Florida. The watershed covers 110,000 acres of which 63,109 were identified as critical agricultural sources of phosphorus entering Lake Okeechobee. These sources were primarily improved pastures and dairies. The project has an extensive pre-BMP water quality data base for statistical comparison with post-BMP data. In addition, most of the BMP implementation occurred in 1985, 1986, and 1987, allowing for four to five years post-BMP water quality monitoring before the end of the project. Therefore, this project should be able to document land treatment effects on water quality. Water quality monitoring data from in-stream sampling was analyzed to determine the magnitu...