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Peter K. Weiskel

Publications and source records attributed to Peter K. Weiskel.

18 recordsLinked to original sources

Selected water-resources activities of the U.S. Geological Survey in New England in 2017

The New England Water Science Center of the U.S. Geological Survey (USGS) is headquartered in Pembroke, New Hampshire, with offices in East Hartford, Connecticut; Augusta, Maine; Northborough, Massachusetts; and Montpelier, Vermont. The areas of expertise covered by the water science center’s staff of 130 include aquatic biology, chemistry, geographic information systems, geology, hydrologic sciences and engineering, and water use.

Connecticut, Maine, Massachusetts, New Hampshire,

Environmental conditions in the Namskaket Marsh Area, Orleans, Massachusetts: A summary of studies by the U.S. Geological Survey, 1989–2011

Namskaket Marsh and its tidal creek system are potential receptors for a treated wastewater plume originating from a septage treatment facility in the northwest part of Orleans, Massachusetts, on Cape Cod. From 1989 to 2011, the U.S. Geological Survey, in cooperation with State and local partners, conducted a series of studies in the Namskaket Marsh area to characterize the potential effects of the plume on the marsh and its tidal creek system. Studies included characterizing the baseline vegetation and salinity distribution in the marsh, monitoring the movement of the wastewater plume downgradient of the septage treatment facility, and sampling nutrient concentrations in the tidal creek system during a baseline period prior to the arrival of the plume at the marsh boundary. The Inner Namskaket Marsh baseline vegetation survey in 1995 found it to be dominated by Phragmites australis (common reed, 44 percent of vegetative cover), Spartina patens (salt marsh hay, 17 percent), and Spartina alterniflora (cordgrass, 9 percent). Phragmites occurrence was correlated with shallow pore-water salinity in the marsh peat and was largely confined to areas with salinities less than 4 parts per thousand. Baseline, ebb-tide nutrient concentrations at the tidal creek sampling stations during 1994–96 showed strong seasonal variations for ammonium, likely associated with the seasonal cycle of growth and senescence for the dominant salt marsh grasses ( S. alterniflora and S. patens ). The seasonal cycle for nitrate was generally less pronounced. The movement of the wastewater plume has been monitored from its source at the septage treatment facility to areas immediately adjacent to and beneath the most inland part of the marsh. In late 1994, the plume was first detected by borehole geophysical logging in observation wells along the Cape Cod Rail Trail (rail trail), 600 feet northwest of the infiltration beds, at an elevation of 47 to 53 feet below the National Geodetic Vertical Datum of 1929 (NGVD 29). At the rail trail, the plume was largely confined below a 3- to 8-foot-thick silt/clay layer detected by borehole geophysical logging and confirmed by lithologic samples. By early 1998, a second plume segment was detected above this silt/clay layer at the rail trail, near the plume’s southwest boundary. Groundwater sampling in 2003–4 at additional stations southwest of the main plume, as well as beneath Namskaket Marsh, defined the extent of this shallow plume segment in glacial sands underlying the marsh. The tidal creek sampling stations established in the 1990s were resampled in 2003–4 and 2010–11 to evaluate potential effects of the treated wastewater plume on creek water quality. The annual medians of the 2011 biweekly nitrate and total dissolved nitrogen concentrations were determined for each station and compared to the annual medians of biweekly samples for the baseline years 1994, 1995, and 1996. At all stations, the 2011 median nitrate concentrations were within the range of medians for the 3 baseline years. A similar result was obtained for total dissolved nitrogen. We conclude that the 2011 creek samples, collected approximately 8 years after the shallow plume segment was first detected beneath the marsh, do not show evidence of elevated nitrate or total dissolved nitrogen concentrations attributable to discharge of either the shallow or deep segments of the treated wastewater plume.

Massachusetts

Groundwater contaminant science activities of the U.S. Geological Survey in New England

Aquifers in New England provide water for human needs and natural ecosystems. In some areas, however, aquifers have been degraded by contaminants from geologic and human sources. In recent decades, the U.S. Geological Survey has been a leader in describing contaminant occurrence in the bedrock and surficial aquifers of New England. In cooperation with Federal, State, and local agencies, the U.S. Geological Survey has also studied the vulnerability of groundwater to contaminants, the factors affecting the geographic distribution of contaminants, and the geochemical processes controlling contaminant transport and fate. This fact sheet describes some of the major science needs in the region related to groundwater contaminants and highlights recent U.S. Geological Survey studies that provide a foundation for future investigations.

New England

Hydrology: The interdisciplinary science of water

We live in a world where biophysical and social processes are tightly coupled. Hydrologic systems change in response to a variety of natural and human forces such as climate variability and change, water use and water infrastructure, and land cover change. In turn, changes in hydrologic systems impact socioeconomic, ecological, and climate systems at a number of scales, leading to a coevolution of these interlinked systems. The Harvard Water Program, Hydrosociology, Integrated Water Resources Management, Ecohydrology, Hydromorphology, and Sociohydrology were all introduced to provide distinct, interdisciplinary perspectives on water problems to address the contemporary dynamics of human interaction with the hydrosphere and the evolution of the Earth’s hydrologic systems. Each of them addresses scientific, social, and engineering challenges related to how humans influence water systems and vice versa. There are now numerous examples in the literature of how holistic approaches can provide a structure and vision of the future of hydrology. We review selected examples, which taken together, describe the type of theoretical and applied integrated hydrologic analyses and associated curricular content required to address the societal issue of water resources sustainability. We describe a modern interdisciplinary science of hydrology needed to develop an in-depth understanding of the dynamics of the connectedness between human and natural systems and to determine effective solutions to resolve the complex water problems that the world faces today. Nearly, every theoretical hydrologic model introduced previously is in need of revision to accommodate how climate, land, vegetation, and socioeconomic factors interact, change, and evolve over time.

Water Resources Research

Hydroclimatic regimes: a distributed water-balance framework for hydrologic assessment, classification, and management

Runoff-based indicators of terrestrial water availability are appropriate for humid regions, but have tended to limit our basic hydrologic understanding of drylands – the dry-subhumid, semiarid, and arid regions which presently cover nearly half of the global land surface. In response, we introduce an indicator framework that gives equal weight to humid and dryland regions, accounting fully for both vertical (precipitation + evapotranspiration) and horizontal (groundwater + surface-water) components of the hydrologic cycle in any given location – as well as fluxes into and out of landscape storage. We apply the framework to a diverse hydroclimatic region (the conterminous USA) using a distributed water-balance model consisting of 53 400 networked landscape hydrologic units. Our model simulations indicate that about 21% of the conterminous USA either generated no runoff or consumed runoff from upgradient sources on a mean-annual basis during the 20th century. Vertical fluxes exceeded horizontal fluxes across 76% of the conterminous area. Long-term-average total water availability (TWA) during the 20th century, defined here as the total influx to a landscape hydrologic unit from precipitation, groundwater, and surface water, varied spatially by about 400 000-fold, a range of variation ~100 times larger than that for mean-annual runoff across the same area. The framework includes but is not limited to classical, runoff-based approaches to water-resource assessment. It also incorporates and reinterprets the green- and blue-water perspective now gaining international acceptance. Implications of the new framework for several areas of contemporary hydrology are explored, and the data requirements of the approach are discussed in relation to the increasing availability of gridded global climate, land-surface, and hydrologic data sets.

Hydrology and Earth System Sciences

Estimated sediment thickness, quality, and toxicity to benthic organisms in selected impoundments in Massachusetts

The U.S. Geological Survey and the Massachusetts Department of Fish and Game, Division of Ecological Restoration, collaborated to collect baseline information on the quantity and quality of sediment impounded behind selected dams in Massachusetts, including sediment thickness and the occurrence of contaminants potentially toxic to benthic organisms. The thicknesses of impounded sediments were measured, and cores of sediment were collected from 32 impoundments in 2004 and 2005. Cores were chemically analyzed, and concentrations of 32 inorganic elements and 108 organic compounds were quantified. Sediment thicknesses varied considerably among the 32 impoundments, with an average thickness of 3.7 feet. Estimated volumes also varied greatly, ranging from 100,000 cubic feet to 81 million cubic feet. Concentrations of toxic contaminants as well as the number of contaminants detected above analytical quantification levels (also known as laboratory reporting levels) varied greatly among sampling locations. Based on measured contaminant concentrations and comparison to published screening thresholds, bottom sediments were predicted to be toxic to bottom-dwelling (benthic) organisms in slightly under 30 percent of the impoundments sampled. Statistically significant relations were found between several of the contaminants and individual indicators of urban land use and industrial activity in the upstream drainage areas of the impoundments. However, models developed to estimate contaminant concentrations at unsampled sites from upstream landscape characteristics had low predictive power, consistent with the long and complex land-use history that is typical of many drainage areas in Massachusetts.

Massachusetts

Hydrologic, vegetation, and soil data collected in selected wetlands of the Big River Management area, Rhode Island, from 2008 through 2010

The Rhode Island Water Resources Board planned to develop public water-supply wells in the Big River Management Area in Kent County, Rhode Island. Research in the United States and abroad indicates that groundwater withdrawal has the potential to affect wetland hydrology and related processes. In May 2008, the Rhode Island Water Resources Board, the U.S. Geological Survey, and the University of Rhode Island formed a partnership to establish baseline conditions at selected Big River wetland study sites and to develop an approach for monitoring potential impacts once pumping begins. In 2008 and 2009, baseline data were collected on the hydrology, vegetation, and soil characteristics at five forested wetland study sites in the Big River Management Area. Four of the sites were located in areas of potential drawdown associated with the projected withdrawals. The fifth site was located outside the area of projected drawdown and served as a control site. The data collected during this study are presented in this report.

Rhode Island

The Massachusetts Sustainable-Yield Estimator: A decision-support tool to assess water availability at ungaged stream locations in Massachusetts

Federal, State and local water-resource managers require a variety of data and modeling tools to better understand water resources. The U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, has developed a statewide, interactive decision-support tool to meet this need. The decision-support tool, referred to as the Massachusetts Sustainable-Yield Estimator (MA SYE) provides screening-level estimates of the sustainable yield of a basin, defined as the difference between the unregulated streamflow and some user-specified quantity of water that must remain in the stream to support such functions as recreational activities or aquatic habitat. The MA SYE tool was designed, in part, because the quantity of surface water available in a basin is a time-varying quantity subject to competing demands for water. To compute sustainable yield, the MA SYE tool estimates a daily time series of unregulated, daily mean streamflow for a 44-year period of record spanning October 1, 1960, through September 30, 2004. Selected streamflow quantiles from an unregulated, daily flow-duration curve are estimated by solving six regression equations that are a function of physical and climate basin characteristics at an ungaged site on a stream of interest. Streamflow is then interpolated between the estimated quantiles to obtain a continuous daily flow-duration curve. A time series of unregulated daily streamflow subsequently is created by transferring the timing of the daily streamflow at a reference streamgage to the ungaged site by equating exceedence probabilities of contemporaneous flow at the two locations. One of 66 reference streamgages is selected by kriging, a geostatistical method, which is used to map the spatial relation among correlations between the time series of the logarithm of daily streamflows at each reference streamgage and the ungaged site. Estimated unregulated, daily mean streamflows show good agreement with observed unregulated, daily mean streamflow at 18 streamgages located across southern New England. Nash-Sutcliffe efficiency goodness-of-fit values are between 0.69 and 0.98, and percent root-mean-square-error values are between 19 and 283 percent. The MA SYE tool provides an estimate of streamflow adjusted for current (2000-04) water withdrawals and discharges using a spatially referenced database of permitted groundwater and surface-water withdrawal and discharge volumes. For a user-selected basin, the database is queried to obtain the locations of water withdrawal or discharge volumes within the basin. Groundwater and surface-water withdrawals and discharges are subtracted and added, respectively, from the unregulated, daily streamflow at an ungaged site to obtain a streamflow time series that includes the effects of these withdrawals and discharges. Users also have the option of applying an analytical solution to the time-varying, groundwater withdrawal and discharge volumes that take into account the effects of the aquifer properties on the timing and magnitude of streamflow alteration. For the MA SYE tool, it is assumed that groundwater and surface-water divides are coincident. For areas of southeastern Massachusetts and Cape Cod where this assumption is known to be violated, groundwater-flow models are used to estimate average monthly streamflows at fixed locations. There are several limitations to the quality and quantity of the spatially referenced database of groundwater and surface-water withdrawals and discharges. The adjusted streamflow values do not account for the effects on streamflow of climate change, septic-system discharge, impervious area, non-public water-supply withdrawals less than 100,000 gallons per day, and impounded surface-water bodies.

Massachusetts

Indicators of streamflow alteration, habitat fragmentation, impervious cover, and water quality for Massachusetts stream basins

Massachusetts streams and stream basins have been subjected to a wide variety of human alterations since colonial times. These alterations include water withdrawals, treated wastewater discharges, construction of onsite septic systems and dams, forest clearing, and urbanization—all of which have the potential to affect streamflow regimes, water quality, and habitat integrity for fish and other aquatic biota. Indicators were developed to characterize these types of potential alteration for subbasins and groundwater contributing areas in Massachusetts. The potential alteration of streamflow by the combined effects of withdrawals and discharges was assessed under two water-use scenarios. Water-use scenario 1 incorporated publicly reported groundwater withdrawals and discharges, direct withdrawals from and discharges to streams, and estimated domestic-well withdrawals and septic-system discharges. Surface-water-reservoir withdrawals were excluded from this scenario. Water-use scenario 2 incorporated all the types of withdrawal and discharge included in scenario 1 as well as withdrawals from surface-water reservoirs—all on a long-term, mean annual basis. All withdrawal and discharge data were previously reported to the State for the 2000–2004 period, except domestic-well withdrawals and septic-system discharges, which were estimated for this study. The majority of the state’s subbasins and groundwater contributing areas were estimated to have relatively minor (less than 10 percent) alteration of streamflow under water-use scenario 1 (seasonally varying water use; no surface-water-reservoir withdrawals). However, about 12 percent of subbasins and groundwater contributing areas were estimated to have extensive alteration of streamflows (greater than 40 percent) in August; most of these basins were concentrated in the outer metropolitan Boston region. Potential surcharging of streamflow in August was most commonly indicated for main-stem river subbasins, although surcharging was also indicated for some smaller tributary subbasins. In the high-flow month of April, only 4.8 percent of subbasins and groundwater contributing areas had more than 10 percent potential flow alteration. A majority of the state’s subbasins and groundwater contributing areas were also indicated to have relatively minor alteration of streamflow under water-use scenario 2 (long-term average water use, including surface-water-reservoir withdrawals). Extensive alteration of mean annual flows was estimated for about 6 percent of the state’s subbasins and groundwater contributing areas. The majority of subbasins estimated to have extensive long-term flow alteration contained reservoirs that were specifically designed, constructed, and managed to supply drinking water to cities. Only a small number of subbasins and groundwater contributing areas (1 percent) were extensively surcharged on a long-term, mean annual basis. Because site-specific data concerning surface-water-reservoir storage dynamics and management practices are not available statewide, the seasonal effects of surface-water-reservoir withdrawals on downstream flows could not be assessed in this study. The impounded storage ratio (volume of impounded subbasin or groundwater-contributing-area storage divided by mean annual predevelopment outflow from the subbasin or contributing area, in units of days) indicates the potential for alteration of streamflow, sediment-transport, and temperature regimes by dams, independent of water use. Storage ratios were less than 1 day for 33 percent of the subbasins and groundwater contributing areas, greater than 1 month for about 40 percent of the cases, and greater than 1 year for 3.2 percent of the cases statewide. Dam density, an indicator of stream-habitat fragmentation by dams, averaged 1 dam for every 6.7 stream miles statewide. Many of these dams are not presently (2009) being managed. The highest dam densities were in portions of Worcester County and in the Plymouth-Carver region, respectively, reflecting the historical reliance of Massachusetts industry upon water power and agricultural water-management practices in southeastern Massachusetts. Impervious cover is a frequently used indicator of urban land use. About 33 percent of the state’s 1,429 subbasins and groundwater contributing areas are relatively undeveloped at the local scale, with a local impervious cover of less than 4 percent. About 18 percent of Massachusetts subbasins and contributing areas are highly developed, with a local impervious cover greater than 16 percent. The remaining 49 percent of subbasins and contributing areas have levels of urban development between these extremes (4 to 16 percent local impervious cover). Cumulative impervious cover, defined for the entire upstream area encompassed by each subbasin, shows a smaller range (0 to 55 percent) than local impervious cover. Both local and cumulative impervious cover were highest in metropolitan Boston and other urban centers. High elevated impervious-cover values were also found along major transportation corridors. The water-quality status of Massachusetts streams is assessed periodically by the Massachusetts Department of Environmental Protection pursuant to the requirements of the Federal Clean Water Act. Streams selected for assessment are commonly located in larger subbasins where some degree of impairment is expected. In the 72 percent of the state’s subbasins and groundwater contributing areas with assessed streams in 2002, more than 50 percent of the assessed stream miles were considered impaired. All of the assessed stream miles were considered impaired in 66 percent of the subbasins and groundwater contributing areas with assessed streams. Large streams, such as the main stems of rivers that make up most of the assessed stream miles, also are in many cases the receiving waters for treated wastewater discharges and for this reason may be more susceptible to water-quality impairments than smaller streams. Subbasins and contributing areas with large fractions of assessed stream miles that are listed as impaired are distributed across the state, but are more prevalent in eastern Massachusetts.

Massachusetts

Simulated Effects of Year 2030 Water-Use and Land-Use Changes on Streamflow near the Interstate-495 Corridor, Assabet and Upper Charles River Basins, Eastern Massachusetts

Continued population growth and land development for commercial, industrial, and residential uses have created concerns regarding the future supply of potable water and the quantity of ground water discharging to streams in the area of Interstate 495 in eastern Massachusetts. Two ground-water models developed in 2002-2004 for the Assabet and Upper Charles River Basins were used to simulate water supply and land-use scenarios relevant for the entire Interstate-495 corridor. Future population growth, water demands, and commercial and residential growth were projected for year 2030 by the Metropolitan Area Planning Council. To assess the effects of future development on subbasin streamflows, seven scenarios were simulated by using existing computer-based ground-water-flow models with the data projected for year 2030. The scenarios incorporate three categories of projected 2030 water- and land-use data: (1) 2030 water use, (2) 2030 land use, and (3) a combination of 2030 water use and 2030 land use. Hydrologic, land-use, and water-use data from 1997 through 2001 for the Assabet River Basin study and 1989 through 1998 for the Upper Charles River Basin study were used to represent current conditions - referred to as 'basecase' conditions - in each basin to which each 2030 scenario was compared. The effects of projected 2030 land- and water-use change on streamflows in the Assabet River Basin depended upon the time of year, the hydrologic position of the subbasin in the larger basin, and the relative areas of new commercial and residential development projected for a subbasin. Effects of water use and land use on streamflow were evaluated by comparing average monthly nonstorm streamflow (base flow) for March and September simulated by using the models. The greatest decreases in streamflow (up to 76 percent in one subbasin), compared to the basecase, occurred in September, when streamflows are naturally at their lowest level. By contrast, simulated March streamflows decreased less than 6.5 percent from basecase streamflows in all subbasins for all scenarios. The simulations showed similar effects in the Upper Charles River Basin, but increased water use contributed to decreased simulated streamflow in most subbasins. Simulated changes in March streamflows for 2030 in the Upper Charles River Basin were within +- 6 percent of the basecase for all scenarios and subbasins. Percentage decreases in simulated September streamflows for 2030 were greater than in March but less than the September decreases that resulted for some subbasins in the Assabet River Basin. Only two subbasins of the Upper Charles River Basin had projected decreases greater than 5 percent. In the Mill River subbasin, the decrease was 11 percent, and in the Mine Brook subbasin, 6.6 percent. Changes in water use and wastewater return flow generally were found to have the greatest effect in the summer months when streamflow and aquifer recharge rates are low and water use is high. September increases in main-stem streamflow of both basins were due mainly to increased discharge of treated effluent from wastewater-treatment facilities on the main-stem rivers. In the Assabet River Basin, wastewater-treatment-facility discharge became a smaller proportion of total streamflow with distance downstream. In contrast, wastewater-treatment facility discharge in the Upper Charles River Basin became a greater proportion of streamflow with distance downstream. The effects of sewer-line extension and low-impact development on streamflows in two different subbasins of the Assabet River Basin also were simulated. The result of extending sewer lines with a corresponding decrease in septic-system return flow caused September streamflows to decrease as much as 15 percent in the Fort Pond Brook subbasin. The effect of low-impact development was simulated in the Hop Brook subbasin in areas projected for commercial development. In this simulation, the greater the area where low-i

Scientific Investigations Report

The Charles River, Eastern Massachusetts: Scientific Information in Support of Environmental Restoration

Human activity has profoundly altered the Charles River and its watershed over the past 375 years. Restoration of environmental quality in the watershed has become a high priority for private- and public-sector organizations across the region. The U.S. Environmental Protection Agency and the Massachusetts Executive Office of Environmental Affairs worked together to coordinate the efforts of the various organizations. One result of this initiative has been a series of scientific studies that provide critical information concerning some of the major hydrologic and ecological concerns in the watershed. These studies have focused upon: * Streamflows - Limited aquifer storage, growing water demands, and the spread of impervious surfaces are some of the factors exacerbating low summer streamflows in headwater areas of the watershed. Coordinated management of withdrawals, wastewater returns, and stormwater runoff could substantially increase low streamflows in the summer. Innovative approaches to flood control, including preservation of upstream wetland storage capacity and construction of a specially designed dam at the river mouth, have greatly reduced flooding in the lower part of the watershed in recent decades. * Water quality - Since the mid-1990s, the bacterial quality of the Charles River has improved markedly, because discharges from combined sewer overflows and the number of illicit sewer connections to municipal storm drains have been reduced. Improved management of stormwater runoff will likely be required, however, for full attainment of State and Federal water-quality standards. Phosphorus inputs from a variety of sources remain an important water-quality problem. * Fish communities and habitat quality - The Charles River watershed supports a varied fish community of about 20 resident and migratory species. Habitat conditions for fish and other aquatic species have improved in many parts of the river system in recent years. However, serious challenges remain, including the control of nutrients, algae, and invasive plants, mitigation of dam impacts, addressing remaining sources of bacteria to the river, and remediation of contaminated bottom habitat and the nontidal salt wedge in the lower river.

General Information Product

Water resources and the urban environment, lower Charles River watershed, Massachusetts, 1630-2005

The Charles River, one of the Nation’s most historically significant rivers, flows through the center of the Boston metropolitan region in eastern Massachusetts. The lower Charles River, downstream of the original head of tide in Watertown, was originally a productive estuary and important source of fish and shellfish for the Native Americans of the region. This portion of the river has an exceptionally long and colorful human history. In 1615, the explorer Captain John Smith gave the river its modern name, in honor of young Prince Charles of England. In 1617–18, the Native American community of the watershed was decimated by an epidemic, after having continuously occupied the area for the previous 4,000 years. In 1630, the first large group of English settlers, led by John Winthrop, set foot on the Shawmut Peninsula at the mouth of the river, and established the town of Boston. In the 1630s, the first printing press, public park, public school, and college in the English colonies were all established on the banks of the Charles River. Almost immediately, the settlers of Boston and adjacent towns also began to modify the landscape and water resources of the watershed. Perhaps the most important type of landscape alteration in the watershed was the filling of the extensive salt marshes and tidal flats of the estuary downstream of Watertown. This landmaking activity along the lower Charles River began in the mid-1600s, and did not conclude until the 1950s. In the early 20th century, the estuary mouth was dammed, creating a freshwater basin in the lower 9.5 miles of the river. A system of parks and parkways was built along the banks of the impounded river. In addition to the mainstem river, virtually all of the remaining water resources in the watershed have also been altered. Most of the river’s tributaries, for example, were culverted, or placed into tunnels, and many of the ponds and freshwater wetlands in the watershed were filled to facilitate urban development. One additional legacy of the river’s long human history is pollution from industry and sewage. By 1875, a total of 43 mills were operating along the lower Charles River between Watertown Dam and Boston Harbor. Thousands of gallons of untreated sewage and industrial wastewater entered the river daily through gravity drains, posing a major threat to public health. Concerted efforts to address the sewage problem began in the late 1870s. By the 1960s, the water quality of the river was significantly improved, yet still not suitable for swimming, fishing, or even boating under most conditions. In 1965, the Charles River Watershed Association was organized and the call to restore the environmental quality of the river and its parklands was heard anew. Passage of the Federal Clean Water Act in 1972 and the subsequent court-ordered reconstruction of the region’s sewage-treatment infrastructure in the 1980s and 1990s (the “Boston Harbor Cleanup”) provided additional impetus to address the river’s remaining pollution problems. In 1995, the U.S. Environmental Protection Agency launched the Clean Charles 2005 Initiative, which brought together government agencies, private-sector institutions, and environmental organizations to focus on restoring the river to fishable and swimmable conditions by Earth Day 2005. This initiative has achieved substantial improvements in water quality; sewage discharges to the river, for example, have been largely eliminated. Nevertheless, it is now widely acknowledged that full attainment of water-quality standards will likely depend upon improved public understanding of the watershed, continued efforts to eliminate illicit sewage discharges to the river, and better management of the urban runoff that enters the river both directly and from its many tributary streams.

Massachusetts

Streamflow, water quality, and contaminant loads in the lower Charles River Watershed, Massachusetts, 1999-2000

Streamflow data and dry-weather and stormwater water-quality samples were collected from the main stem of the Charles River upstream of the lower Charles River (or the Basin) and from four partially culverted urban streams that drain tributary subbasins in the lower Charles River Watershed. Samples were collected between June 1999 and September 2000 and analyzed for a number of potential contaminants including nitrate (plus nitrite), ammonia, total Kjeldahl nitrogen, phosphorus, cadmium, chromium, copper, lead, and zinc; and water-quality properties including specific conductance, turbidity, biochemical oxygen demand, fecal coliform bacteria, Entero-coccus bacteria, total dissolved solids, and total suspended sediment. These data were used to identify the major pathways and to determine the magnitudes of contaminants loads that contribute to the poor water quality of the lower Charles River. Water-quality and streamflow data, for one small urban stream and two storm drains that drain subbasins with uniform (greater than 73 percent) land use (including single-family residential, multifamily residential, and commercial), also were collected. These data were used to elucidate relations among streamflow, water quality, and subbasin characteristics. Streamflow in the lower Charles River Watershed can be characterized as being unsettled and flashy. These characteristics result from the impervious character of the land and the complex infrastructure of pipes, pumps, diversionary canals, and detention ponds throughout the watershed. The water quality of the lower Charles River can be considered good?meeting water-quality standards and guidelines?during dry weather. After rainstorms, however, the water quality of the river becomes impaired, as in other urban areas. The poor quality of stormwater and its large quantity, delivered over short periods (hours and days), together with illicit sanitary cross connections, and combined sewer overflows, results in large contaminant loads that appear to exceed the river?s assimilative capacity. Annual contaminant loads from stormwater discharges directly to the lower Charles River are large, but most dry-weather and stormwater contaminant loads measured in this study originate from upstream of the Watertown Dam and are delivered to the lower Charles River in mainstem flows. An exception is fecal coliform bacteria. Stony Brook, a large tributary influenced by combined sewer overflow, contributed almost half of the annual fecal coliform load to the lower Charles River for Water Year 2000. Much of this fecal coliform bacteria load is discharged from Stony Brook to the lower Charles River during rain-storms. Estimated stormwater loads for future conditions suggest that sewer separation in the Stony Brook Subbasin might reduce loads of constituents associated with sewage but increase loads of constituents associated with street runoff. The unique environment offered by the lower Charles River must be considered when the environmental implications of large contaminant loads are interpreted. In particular, the lower Charles River has low hydraulic gradients, a lack of tidal flushing, a lack of natural uncontaminated sediment from erosion of upstream uncontaminated soils, and an anoxic, sulfide-rich bottom layer that forms a non-tidal salt wedge in the downstream part of the lower Charles River. Individually and in combination, these characteristics may increase the likelihood of adverse effects of some contaminants on the water, biota, and sediment of the lower Charles River.

Water-Resources Investigations Report

Potential effects of structural controls and street sweeping on stormwater loads to the lower Charles River, Massachusetts

The water quality of the lower Charles River is periodically impaired by combined sewer overflows (CSOs) and non-CSO stormwater runoff. This study examined the potential non-CSO load reductions of suspended solids, fecal coliform bacteria, total phosphorus, and total lead that could reasonably be achieved by implementation of stormwater best management practices, including both structural controls and systematic street sweeping. Structural controls were grouped by major physical or chemical process; these included infiltration-filtration (physical separation), biofiltration-bioretention (biological mechanisms), or detention-retention (physical settling). For each of these categories, upper and lower quartiles, median, and average removal efficiencies were compiled from three national databases of structural control performance. Removal efficiencies obtained indicated a wide range of performance. Removal was generally greatest for infiltration-filtration controls and suspended solids, and least for biofiltration-bioretention controls and fecal coliform bacteria. Street sweeping has received renewed interest as a water-quality control practice because of reported improvements in sweeper technology and the recognition that opportunities for implementing structural controls are limited in highly urbanized areas. The Stormwater Management Model that was developed by the U.S. Geological Survey for the lower Charles River Watershed was modified to simulate the effects of street sweeping in a single-family land-use basin. Constituent buildup and washoff variable values were calibrated to observed annual and storm-event loads. Once calibrated, the street sweeping model was applied to various permutations of four sweeper efficiencies and six sweeping frequencies that ranged from every day to once every 30 days. Reduction of constituent loads to the lower Charles River by the combined hypothetical practices of structural controls and street sweeping was estimated for a range of removal efficiencies because of their inherent variability and uncertainty. This range of efficiencies, with upper and lower estimates, provides reasonable bounds on the load that could be removed by the practices examined. The upper estimated load reduction from combined street sweeping and structural controls, as a percentage of the total non-CSO load entering the lower Charles River downstream of Watertown Dam, was 44 percent for suspended solids, 34 percent for total lead, 14 percent for total phosphorus, and 17 percent for fecal coliform bacteria. The lower estimated load reduction from combined street sweeping and structural controls from non-CSO sources downstream of Watertown Dam, was 14 percent for suspended solids, 11 percent for total lead, 4.9 percent for total phosphorus, and 7.5 percent for fecal coliform bacteria. Load reductions by these combined management practices can be a small as 1.4 percent for total phosphorus to about 4 percent for the other constituents if the total load above Watertown Dam is added to the load from below the dam. Although the reductions in stormwater loads to the lower Charles River from the control practices examined appear to be minor, these practices would likely provide water-quality benefits to portions of the river during those times that they are most impaired-during and immediately after storms. It should also be recognized that only direct measurements of changes in stormwater loads before and after implementation of control practices can provide definitive evidence of the beneficial effects of these practices on water-quality conditions in the lower Charles River.

Massachusetts

Distribution and potential for adverse biological effects of inorganic elements and organic compounds in bottom sediment, lower Charles River, Massachusetts

Surficial-sediment samples and cores collected from the lower Charles River Basin are generally enriched in inorganic elements and organic compounds, including polychlorinated byphenyls, total organochlorine pesticides, and polyaromatic hydrocarbons. Median concentrations of selected inorganic elements and organic compounds measured in surficial-sediment samples collected from the lower Charles River ranged from 1. 3 to 3 5 times higher than median concentrations of these constituents measured in samples collected from urban rivers across the conterminous United States by the U.S. Geological Survey's National Water Quality Assessment Program (NAWQA). The distribution of the inorganic elements in surficial sediment throughout the basin appears to be controlled primarily by in-stream processes associated with sediment transport and the presence of an anoxic zone within a non-tidal salt wedge in the basin. In contrast, the distribution of organic compounds appears to reflect local point and non-point sources. Inorganic elements and organic compounds are present at sufficiently high concentrations at many surficial-sediment sampling sites to cause potentially severe biological effects to benthic organisms living in and on the bottom sediment. Ratios of acid volatile sulfide to simultaneously extracted metals, however, suggest that some inorganic elements would be toxic in fewer than 25 percent of the surficial-sediment samples. Many individual polyaromatic hydrocarbons, total petroleum hydrocarbons, and lead measured in cores exceeded exposure-based soil-concentration standards for direct contact and incident ingestion at areas where restoration of public wading and swimming beaches is being considered.

Massachusetts

Hydrologic indices for nontidal wetlands

Two sets of hydrologic indices were developed to characterize the water-budget components of nontidal wetlands. The first set consisted of six water-budget indices for input and output variables, and the second set consisted of two hydrologic interaction indices derived from the water-budget indices. The indices then were applied to 19 wetlands with previously published water-budget data. Two trilinear diagrams for each wetland were constructed, one for the three input indices and another for the three output indices. These two trilinear diagrams then were combined with a central quadrangle to form a Piper-type diagram, with data points from the trilinear diagrams projected onto the quadrangle. The quadrangle then was divided into nine fields that summarized the water-budget information. Two quantitative "interaction indices" were calculated from two of the six water-budget indices (precipitation and evapotranspiration). They also were obtained graphically from the water-budget indices, which were first projected to the central quadrangle of a Piper-type diagram from the flanking trilinear plots. The first interaction index (l) defines the strength of interaction between a wetland and the surrounding ground- and surface-water system. The second interaction index (S) defines the nature of the interaction between the wetland and the surrounding ground- and surface-water system (source versus sink). Evaluation of these indices using published wetland water-budget data illustrates the usefulness of the technique.

Wetlands