Tidal river sediments in the Washington,D.C. area. III. Biological effects associated with sediment contamination

Sediment toxicity and benthic macroinvertebrate community structure were measured as one component of a study cohceived to determine the distribution and effect of sediment contamination in tidal freshwater portions of the Potomac and Anacostia rivers in the Washington, D.C., area. Samples were collected at 15 sites. Analyses included a partial life cycle (28 d) whole sediment test using the amphipod Hyalella azteca (Talitridae) and an assessment of benthic community structure. Survival and growth (as estimated by amphipod length) were experimental endopoints for the toxicity test. Significant mortality was observed in 5 of 10 sites in the lower Anacostia River basin and at the main channel Potomac River site. Sublethal toxicity, as measured by inhibition of amphipod growth, was not observed. Toxicity test results were in general agreement with synoptically measured sediment contaminant concentrations. Porewater total ammonia (NH₃+NH₄ ⁺) appears to be responsible for the toxicity of sediments from the Potomac River, while correlation analysis and simultaneously extracted metals: acid volatile sulfide (SEM∶AVS) results suggest that the toxicity associated with Anacostia River sediments was due to organic compounds. Twenty-eight macroinvertebrate taxa were identified among all sites, with richness varying from 5 to 17 taxa per site. Groups of benthic assemblages identified by group-average cluster analysis exhibited variable agreement with sediment chemical and sediment toxicity results. Integration of toxicological, chemical, and ecological components suggests that adverse environmental effects manifest in the lower Anacostia River benthos result from chemical contamination of sediment.     

Sedimentation,dredging, and spoil disposal in a subtropical estuarine lagoon

Kaneohe Bay, Hawaii, is an estuary used as a harbor for a military installation and for recreation, fishing, and research purposes. Rapid shoaling of the bay had been reported and attributed to increased stream erosion and sedimentation from the newly suburbanized watershed. Comparison of a 1976 bathymetric survey of Kaneohe Bay with that of a 1927 survey indicates an average shoaling of the lagoonal area of 1.0 m. Average shoaling for the north and middle bay at 0.6m/49 years (1.2 cm yr⁻¹ is lower than for the south bay at 1.5m/49 years (3.1 cm yr⁻¹). The total lagoonal fill in the 49-year period is about 1.95× 10⁷ m³, assigned as follows: 64% carbonate detritus from the reefs as well as growth of living coral and unrecorded dredging spill, 9% recorded dredging spoils, and only 27% terrigenous sediment. Seismic reflection profiles distinguish spoil from natural sediment and show that the infilling sediment is trapped between, burying reef structures built during Quaternary lower stands of the sea. There had been little obvious change between 1882 and 1927 surveys. All information suggests that increased shoaling rates since 1927 are due to reported and unreported disposal of dredge spoil, mainly from 1939 to 1945 for ship and seaplane channels in the south bay, and not from increased runoff and urbanization around the south bay. Hawaii Institute of Geophysics Contribution No. 1257.     

Holocene evolution of a coastal lagoon, Lake of Tunis, Tunisia

Historical records demonstrate that the Lake of Tunis, Tunisia, was an open bay that became separated from the Mediterranean by an accreting barrier spit, forming a lagoon. Closure of the lagoon was caused by increased sedimentation as a consequence of Roman deforestation of the Medjerda River drainage basin to the north and subsequent accelerated longshore transport. The separation of the lagoon from the Mediterranean was completed in the early 1500s. At present, the 48 km² lagoon averages less than 1 m in depth and reaches eutrophic conditions in the late summer. Consistent with the historical records, the lagoon sedimentary column shows three distinct successive environments of deposition: (1) an arid continental environment; (2) an open marine bay; and (3) the present brackish to hypersaline lagoon. These depositional environments are represented by the lower grey layer, which is less than 0-5 m thick, the middle olive-grey layer, which varies from 1 to 5 m in thickness, and the upper black layer, which is 1 m thick. All of the strata are predominantly silt plus clay, but usually contain at least 10% sand. The lower grey layer consists of pitted quartz sand, with very few abraded, broken molluscan fragments and benthic foraminifera with thick tests. An arid, subaerial depositional environment of latest Pleistocene time best explains these sediment and fossil assemblages. In the middle olive-grey layer, coral, coralline algae, open marine graeses and the dominance of foraminifera over ostracods (expressed as a low percentage of ostracods/ostracods plus foraminifera) attest to a depositional environment of an open marine bay. A sharp increase in the percentage of ostracods/ostracods plus foraminifera and organic carbon from the middle olive-grey layer to the upper black layer signifies a major change in depositional environment. The predominance of ostracods over foraminifera, abundance of gastropods characteristic of eutrophic conditions, high organic carbon content and absence of macro-fossils characteristic of open marine conditions clearly indicate that the upper black layer was deposited in a brackish to hypersaline, eutrophic lagoon which has persisted to the present. Seismic records indicate a karstic bedrock surface underlying the lagoon. The surface is marked by considerable relief, and shows a linear depression which may represent an early sixteenth century ship canal. Heavy metal analyses of total samples in five cores demonstrate that Mn and Fe vary randomly, and are apparently derived from natural sources only. Cd, Cr, Pb, Cu and Zn are typically highest in the uppermost unit, which reflects levels of human contamination since closure of the lagoon.     

Hydrochemical characteristics and groundwater quality assessment in Tirupur Region, Coimbatore District, Tamil Nadu, India

Groundwater samples from 62 locations have been collected from Tirupur region viz. Avinashi, Tirupur and Palladam taluks of Coimbatore District. The extensive agricultural industrial activities and urbanization resulted in the contamination of the aquifer. To study the contamination of groundwater, water samples were collected in an area of 180 km² and analysed for major cations and anions. Most of the locations are contaminated by higher concentration of EC, TDS, K and NO₃. Major hydro chemical facies were identified using Piper trilinear diagram. Based on US salinity diagram, most of the samples fall in the field of C3S1, indicating high salinity and low sodium water, which can be used for almost all types of soil with little danger of exchangeable sodium. Majority of the samples are not suitable for domestic purposes and far from drinking water standards. However, PI values indicates that groundwater is suitable for irrigation.     

泉州-湄州湾地区地表环境质量地球化学评价初探

本文利用地矿部门网格化均匀布设的水系沉积物组合样品的定量分析结果,通过计算机直接制成污染指数分级图,对泉州—湄州湾地区近八千平方公里范围,进行地表环境质量评价,指出了引起环境污染的类型.     

Geological and geochemical examination of arsenic contamination in groundwater in the Holocene Terai Basin, Nepal

Geological and geochemical study has been carried out to investigate arsenic contamination in groundwater in Nawalparasi, the western Terai district of Nepal. The work carried out includes analyses of core sediments, provenance study by rare earth elements analyses, ¹⁴C dating, and water analyses. Results showed that distribution of the major and trace elements are not homogeneous in different grain size sediments. Geochemical characteristics and sediment assemblages of the arsenic contaminated (Nawalparasi) and uncontaminated (Bhairahawa) area have been compared. Geochemical compositions of sediments from both the areas are similar; however, water chemistry and sedimentary facies vary significantly. Extraction test of sediment samples showed significant leaching of arsenic and iron. Chemical reduction and contribution from organic matter could be a plausible explanation for the arsenic release in groundwater from the Terai sediments.     

Sulphide-mining impacts in the physical environment: Sierra de Cartagena–La Unión (SE Spain) case study

The environmental impact and potential-risk assessment of an abandoned sulphide-mining site in a semiarid climate is presented here, by the study case of Sierra de Cartagena–La Unión (SE Spain), a 2,500-year-old mining district extending over an area of 100 km². The regional map illustrates the existence of 12 open-pits, 1,902 mining wells, 2,351 waste deposits, including 89 tailing dams and waste rock derived from mining processes. Mine wastes occupy an area of 9 km² and have an approximate volume of 200 Mm³. Mineralogical, physical and chemical data distinguish nine different types of mine and metallurgical waste. According to the concentration of sulphate and heavy metals in sediment, soil, rainwater, surface water and groundwater samples, it is possible to conclude that the impact of mine activities occurs not only in the immediate mining area (100 km²), but also in the surrounding areas (an affected area of 1,000 km² approximately). The hydrochemical data show that groundwater, runoff water and some rainwater samples exceed Spanish and European water quality guideline values for water supply. The main geochemical process recognised is sulphide-mineral oxidation and later-generated sulphate dissolution by groundwater and runoff. Runoff and wind are the major mechanisms of metals and sulphate transport in the study area and adjacent zones.     

Comparative hydrochemistry of five nested catchments located in the upper part of the Barcés river watershed (A Coruña,NW Spain)

259 stream water and 21 bulk precipitation samples have been studied between April 2008 and December 2010 in order to assess baseline hydrochemical conditions in a rural area of NW Spain. Stream waters are related to five nested catchments (<10 km²) with apparent low mean residence times. Their hydrochemical characteristics are closely related to bulk precipitation although clear evidences of seasonal (flushing, dilution, sediment desorption, etc.), lithological (schist vs. granite substrate) and anthropogenic (land use, contamination) effects are also described.     

Relationships Among Exceedences of Sediment Guidelines,the Results of Ambient Sediment Toxicity Tests,and Community Metrics in Estuarine Systems

To use bioassessments to help diagnose or identify the specific environmental stressors affecting estuaries, we need a better understanding of the relationships among sediment chemistry guidelines, ambient toxicity tests, and community metrics. However, this relationship is not simple because metrics generally assess the responses at the community level of biological organization whereas sediment guidelines and ambient toxicity tests generally assess or are based on the responses at the organism level. The relationship may be further complicated by the influence of other chemical and physical variables that affect the bioavailability and toxicity of chemical contaminants in the environment. Between 1990 and 1993, the U.S. Environmental Protection Agency (USEPA) conducted an Environmental Monitoring and Assessment Program (EMAP) survey of estuarine sites in the Virginian Province of the eastern United States. The surveys collected data on benthic assemblages, physical and chemical habitat characteristics, and sediment chemistry and toxicity. We characterized these estuarine sites as affected by sediment contamination based on the exceedence of sediment guidelines or on ambient sediment toxicity tests (i.e., 10-day Ampelisca abdita survival). Then, benthic invertebrate metrics were compared among affected and unaffected sites to identify metrics sensitive to the contamination. A number of benthic invertebrate metrics differed between groups of sites segregated using the organism-level measures whereas other metrics did not. The difference among metrics appears to depend on the sensitivity of the individual metrics to the stressor gradient represented by metals or persistent organic toxics in sediments because the insensitive metrics do not effectively quantify the changes in the benthic invertebrate assemblage associated with these stressors. The significant relationships suggest that a relationship exists between the organism-level effects assessed by chemistry or ambient toxicity tests and the community-level effects assessed by community metrics and that the organism-level effects are predictive, to some extent, of community-level effects.     

Representativity of wide-spaced lower-layer overbank sediment geochemical sampling

To develop a technique of implementing global ultra-low density geochemical sampling and as a contribution to the International Geochemical Mapping Program (IGCP Project No. 259), an orientation study in the use of deep (lower-layer) overbank sediments was conducted in Jiangxi Province of Southeast China in 1989–1990. Ninety-four samples were collected at depths of 50 to 120 cm from overbank terraces at an average density of 1 site per 1800 km². The total area of sampled catchment basins is approximately equivalent to 18% of Jiangxi Province. Most of the samples were collected at outflow sites of catchment basins with areas of 100 to 800 km². The samples were analyzed for 39 elements.The representativity of wide-spaced lower-layer overbank sediment sampling is discussed from various perspectives; the following features have been observed: (1) Widespaced lower-layer overbank sediment data and the data from China's national geochemical mapping (RGNR) project show similar geochemical patterns for W, Sn, Pb, Cu and Zn. (2) The results of wide-spaced lower-layer overbank sediment sampling demonstrate that catchment basins with areas of 100 to 800 km² are suitable sample site locations for the global geochemical reference network. (3) Wide-spaced lower-layer overbank sediment sampling is a fast and cost-effective way to identify geochemical provinces and has strategic significance in mineral exploration. (4) There is a significant correlation between the W content of wide-spaced lower-layer overbank sediment samples and the presence of W mineralizations within the catchment basins. (5) The distributions of Ni, Cr and V in wide-spaced lower-layer overbank sediment samples distinctly reveals the boundary between the Yangtze sedimentary platform and the South China Caledonian fold system in Jiangxi Province. (6) Distributions of Rb and Be coincide with the Yanshan granites, which are closely related to the major ore-forming episodes in Jiangxi Province.     

Hydrological and geochemical characteristics of the Jamari and Jiparana river basins (Rondonia,Brazil)

The authors investigate the hydrological and geochemical characteristics of the Jamari (30430 km²) and Jiparana (60350 km²) river basins (Amazonia), during the period 1978–1984. A spectral analysis of Fourier is applied to time series of mean monthly river discharges, in order to assess the contribution (7 to 8%) of the surface runoff to the total river flow. The mean annual runoff coefficient calculated for the Jiparana river basin (36%), is higher than for the Jamari (32%), and this coefficient increases during the study period, only for the Jiparana. The total specific suspended sediment discharge calculated for both rivers shows the same value 13 t/km²/y, and the estimated suspended sediment concentration in the surface runoff is slightly superior for the Jiparana river (0.3 g/l) than for the Jamari one (0.2 g/l). The river suspended sediments are mainly composed of kaolinite, quartz and feldspar, but the Jiparana is more enriched in quartz. For both rivers, the dominant clay mineral is the kaolinite which is in agreement with the rock weathering type determined for both basins using the Tardy's weathering index: the monosiallitisation. The total chemical erosion rate calculated after correction for the atmospheric inputs (ions and CO₂), is higher for the Jiparana (10.11 t/km²/y) than for the Jamari river basin (7.75 t/km²/y). These values are lower than the mechanical denudation rate calculated previously for both river basins.     

A GIS-based approach for detecting pollution sources and bioavailability of metals in coastal and marine sediments of Chabahar Bay,SE Iran

Chabahar Bay in SE of Iran is a shallow semi-enclosed environment affected by anthropogenic activities. In this paper, 19 sediment samples were collected and concentration of selected metals (Cu, Pb, Zn, Cd, Ni, Cr, Co, V and Fe) was determined using ICP-MS analytical method. Sediment samples from five stations were also selected for sequential extraction analysis and concentration of metals in each fraction was determined using ICP-OES. In order to investigate the environmental quality of Chabahar Bay, geographic information system (GIS) along with geochemical data, environmental indices and statistical analyses were used. Calculated contamination degree (C_d) revealed that most contaminated stations (Ch3, S1 and S3) are located SE of Chabahar Bay and contamination decreases in a NW direction. The S9 station, west of the bay, is also contaminated. High organic matter (OM) content in the sediments is most likely the result of fuel and sewage discharge from fishing vessels along with discharge of fishing leftovers. Significant correlation coefficient among OM, Fe, Cu, Pb, Zn and Cd seemingly reflects the importance of the role that OM and Fe oxy-hydroxides play in the metals mobility. The results of hierarchical cluster analysis (HCA), computed correlation coefficient and sequential extraction analysis suggest that Cu, Pb, Zn and Cd probably come from antifouling and sea vessel paints, while Ni, Cr, Co, V and Fe are most likely contributed by ophiolitic formations located north of the bay and/or deep sea sediments. Average individual contamination factors (ICFs) indicated that the highest health hazard from the bay is posed by Cu, Pb and Zn.     

Mobility and ecological risk assessment of heavy metals in surface sediments of Xiamen Bay and its adjacent areas,China

Xiamen Bay (XMB) has received substantial loadings of pollutants from industrial and municipal wastewater discharged since the 1980s. To assess ecological risks and the current spatial changes of metal contaminants in bottom surface sediments, 12 samples were collected. Samples were subjected to a total digestion technique and analyzed by ICP–OES for Cu, Pb, Zn, Cr, and Cd, and by AFS for Hg and As. Among these metals, Zn had the highest values (68–268 mg kg⁻¹), followed by Pb (27–71 mg kg⁻¹), and lower concentrations were found for Cd (42–1,913 μg kg⁻¹) and Hg (0–442 μg kg⁻¹). In comparison with the average crustal abundance values, the results indicated that nearly half of the sediment samples of XMB and its adjacent areas were contaminated by Cd, Pb, Zn, and As. Furthermore, based on the modified BCR sequential extraction procedure, the chemical speciation of heavy metals (Cd, Cr, Cu, Pb, Zn, Hg, and As) in selected sediment samples were evaluated in this study. Data from BCR sequential extractions indicated that Cd posed a medium ecological risk, whereas, Cr posed low risk since its exchangeable and carbonate fractions were below 4%, and the mobility of heavy metals in XMB decreased in the order Cd > Pb > Cu > Zn > Hg > As > Cr. By applying mean effects range median quotients (mERMQ), the results showed that Yuandang Lagoon with mERMQ value >0.5 would be expected to have the greatest potential toxic risk in amphipod within XMB and its adjacent areas.     

Application of geospatial modelling technique in delineation of fluoride contamination zones within Dwarka Basin,Birbhum, India

Dwarka River Basin is one of the fluoride affected river basin in Birbhum, West Bengal. In the present research work, various controlling factors for fluoride contamination in groundwater i.e., geology, aquifer type, groundwater table, soil, rainfall, geomorphology, drainage density, land use land cover, lineament and fault density, slope and elevation were considered to delineate the potential fluoride contamination zones within Dwarka River Basin in Birbhum. Assigning weights and ranks to various inputs factor class and their sub-class respectively was carried out on the basis of knowledge driven method. Weighted overlay analysis was carried out to generate the final potential fluoride contamination zones which are classified into two broad classes i.e., ‘high’ and ‘low’, and it is observed that major portion of the study area falls under low fluoride contamination category encompassing 88.61% of the total area which accounts for 759.48 km² and high fluoride contaminated region accounts for 11.40% of the total study area encompassing an area of about 97.67 km². Majority of high fluoride areas fall along the flood plain of Dwarka River Basin. Finally, for validation 197 reported points within Dwarka having fluoride in underground water are overlaid and an overall accuracy of 92.15% is observed. An accuracy of 83.21% and 84.24% is obtained for success and prediction rate curve respectively.     

Overbank sediments from the surroundings of the Russian nickel mining and smelting industry on the Kola Peninsula

 Top and bottom samples of overbank sediments were collected at 43 sites within a 12 000 km² area around the nickel smelter in Nikel and the ore roasting plant at Zapoljarnij, in northwestern Russia. In addition, three detailed overbank profiles were sampled in 10-cm sections from three catchments representing different levels of pollution. All samples were analysed for more than 30 elements by ICP-AES following aqua regia extraction. Results obtained show that overbank sediments represent natural (geogenic) background levels rather well. Although the major pollutants (Co, Cu, Ni and S) are strongly enriched at some places close to industry, overbank sediment is not especially well suited for mapping the extent of airborne contamination in the area. Co, Cu, Ni and S are mobile within the profile collected from the most polluted catchment. Received: 23 July 1996 · Accepted 18 October 1996     

GIS-based colour composites and overlays to delineate heavy metal contamination zones in the shallow alluvial aquifers, Ankaleshwar industrial estate, south Gujarat, India

In an attempt to delineate heavy metal contamination precincts and to evaluate the extent and degree of toxic levels, besides their possible sources, 38 water samples from Ankaleshwar Industrial Estate, south Gujarat, India were analyzed. By clutching geochemical analyses and GIS-based colour composites areas depicting anomalously high concentration of heavy metals (Mo, Zn, Pb, Ni, Co, Cd, etc.) in the groundwater were revealed. The multicomponent overlays in grey-scale facilitated in identifying situates of heavy metal ‘hot spots’, and lateral protuberances of the contamination plume around defile stretch of the main stream Amla Khadi flowing through the area. The multiple pollution plumes emerging from other parts of the area further coincide with effluent laden streams and small channels indicating industrial establishments as major sources of groundwater contamination. Influent nature of the streams, accelerated infiltration process, high mass influx and shallow groundwater table are the factors conducive for easy access of heavy metals to the phreatic aquifers affecting over 20 km² area. On the basis of P/U ratios (concentration of metals in polluted water to unpolluted water), geogenic and anthropogenic sources have been identified. Very high levels of technogenic elements present in the ground water raise concerns about possible migration into food crops, as the area is an important horticultural locale and is highly cultivated.     

Sediment yield in the Patuxent River (Md.) undergoing urbanization, 1968–1969

Water discharge from the Patuxent River into its estuary was near-average (95%) during the water year 1968–1969 although precipitation was only 79% of the average. Suspended-sediment discharge into the estuary, however, was more then double the normal yield (344 metric tons/km² compared to 143 metric tons/km²). These increases in runoff and suspended-sediment yields, despite decreased precipitation, must be attributed to urbanization of the drainage basin.The maximum measured suspended-sediment concentrations in the rural Middle Patuxent basin (Piedmont Province) increased only 40-fold during an increase from “average” to high water runoff (15 mg/l to 600 mg/l). In the portion of the Little Patuxent River basin undergoing urbanization (Piedmont portion), stream concentrations increased by over two orders of magnitude (20 mg/l to 2400 mg/l) as a result of heavy rainfall. The area undergoing urbanization of the Little Patuxent yielded more than twice as much suspended sediment per unit area as the rural Middle Patuxent (620 metric tons/km² versus 290 metric tons/km²). This increase also is interpreted to be the direct result of erosion of soils denuded or disturbed during urban construction.Using the Middle Patuxent as a “standard” for normal erosion rates in rural areas, construction sites contributed about 82% of the suspended sediment discharged by the Patuxent River into its estuary even though such sites represented only 23% of the drainage basin.     

Sediment origin and budget in Sepetiba Bay (Brazil) - an approach based on multielemental analysis

 Sediment origin and transport were determined in a shallow 447 km² coastal lagoon in Brazil, using the distribution of major elements in bottom and suspended sediments. Applying multivariate analysis, the sum of normalized concentrations of Ti, Fe, and Al in sediments was selected to trace the terrigenous influence in bottom sediments, whereas Ca, Si, and K were used as indicators of marine influence. Sepetiba Bay bottom sediments are dominated by up to 80% terrigenous inputs. The open bay sediments are enriched in P, Mg, K, and Ca because of the intensive water column primary production. The inner bay forms an independent circulation cell with a predominance of terrigenous sediments. The results suggest a long residence time for particles in the bay, demonstrated by the magnitude of resuspension flux compared to the total sediment input to the bay. Received: 29 May 1996 · Accepted: 17 December 1996     

High spatial resolution sampling of metals in the sediment and water column in Port Jefferson Harbor, New York

Eighteen sediment samples and six water-column samples were collected in a small (6 km²), coastal embayment (Port Jefferson Harbor, New York) to define a high-resolution spatial distribution of metals and to elucidate sources of contaminants to the harbor. Sediment metal (Ag, Cu, Fe, Ni, Pb, V, and Zn) concentrations varied widely, reflecting differences in sediment grain size, with higher metal concentrations located in the fine-grained inner harbor sediments. Calculated enrichment factors for these sediments show that Ag, Pb, Cu, and Zn are elevated relative to both crustal abundances and their respective abundances in sediments in central Long Island Sound. Metal concentrations were 1.2 to 10 fold greater in water from the inner harbor compared to water from Long Island Sound collected outside the mouth of the harbor. Spatial variations in trace metals in surface waters within the bay parallel the spatial variations of trace metals in sediments within the harbor. Elevated water-column metal concentrations appear to be partially derived from a combination of diagenetic remobilization from contaminated sediments (e.g., Ag) and anthropogenic sources (e.g., Cu and Zn) within the southern portions of the harbor. Although the National Status and Trends Program had reported previously that sediment metal concentrations in Port Jefferson Harbor were low, the results of this study show sediment metals have high spatial variability and are enriched in the inner harbor sediments at levels comparable to more urbanized western north shore Long Island harbors.     

False drainage anomalies (?) in a granite area, Kvalöya in Troms, Norway — a case study

An anomalous area (100 km²) revealed by a previous regional overbank sediment sampling survey by the Geological Survey of Norway was followed-up for Ti, Nb, Y, Zr, La and Ce by drainage and lithogeochemical sampling and analyses. The drainage samples were anomalous in the same elements as in the overbank samples and contained similar concentrations. The lithogeochemical results did not indicate mineralization and showed only a small enhancement of Ti, Zr, La and Ce in mylonitic rocks.Mineralogical studies of the drainage samples revealed, apart from proportions of quartz and feldspars, that stream sediments and heavy mineral concentrates are similar in mineralogy, with epidote predomination and several vol% of fine-grained titanite and zircon. Drainage samples contained amounts of Nb, Y, and Zr up to ten times larger than average contents of rock samples. Enhanced light REE (La and Ce) and Nb reflect host minerals, titanite, and enhanced Y possibly zircon and/or allanite.Anomalies in both media do not relate to mineralization. The overbank samples and the drainage samples provide comparable geochemical data.