• Carbon uptake on land: how much is it helping control global warming?
• What are the threats and resources for future carbon uptake in local systems?
• Heavy metal contamination in the local environment?
• Local water quality: What is going on at the hotspots?
• What are the new approaches in bioremediation, phytoremediation, and living systems and how do they compare with conventional methods of waste treatment and cleanup?
  

Carbon uptake on land: how much is it helping to control global warming?

Context:
The prospect of serious negative impacts of global warming is strong motivation to arrest increases in concentrations of climate-altering gases in the atmosphere. On a global scale, rising atmospheric carbon dioxide levels, which strongly enhance the greenhouse effect, are the dominant human influence on climate. Fortunately, of the carbon dioxide we emit to the atmosphere, only about half remains there - the rest is removed by various processes on land and in the ocean. There is currently great debate about where this removal is occurring, whether this removal rate will continue, and how these removal processes should be considered in global CO2 control strategies. Should regions or countries get "credit" for the CO2 taken up in their boundaries, and use it to "offset" emissions? How much C is there and how easy is it to measure this uptake on local or regional scales?

On the local scale, Williams student Carlos Silva recently completed an inventory of CO2 emissions of Williamstown and the College, which projected 10% growth in emissions from the year 2000 to 2010 period. However, Williamstown is considering signing on to "Cities for Climate Protection," a growing list of cities who pledge to "meet or beat" the carbon dioxide reduction targets laid out in the Kyoto Protocol (regardless of whether the US commits to Kyoto). By 2010, the town would like to reduce emissions by 20% relative to 2000 levels.

Your study:
Locally, how much carbon is stored in the landscape, and how much is taken up each year? You need to complete an initial study measuring which land areas store the most carbon, estimate how much carbon is stored in these areas in Williamstown, and estimate the net rate at which these areas are either taking up carbon from the atmosphere or releasing it back to the atmosphere.

Tools will include surveying vegetation biomass, measuring carbon content of biomass and soils, evaluating land use distributions from existing data, and using past vegetation survey data to establish carbon uptake rates.

The implications:
Is Williamstown a net source or sink of CO2 to the atmosphere? To what extent should these carbon storages and uptakes be used to meet Williamstown's Kyoto Protocol target? Should Williamstown promote certain land uses relative to others?

Context of the problem:
If land ecosystems are a potential sink of greenhouse-enhancing carbon dioxide, prospects for future uptake depend on the health of these systems and the resources available for their future growth
In the early 1980's, acid rain came to the forefront of public environmental awareness as a major threat to the health of forests and lakes. The problem was especially pronounced in the Northeastern U.S., downwind of many coal power plants whose SO2 emissions generated sulfuric acid in precipitation. The Clean Air Act and subsequent legislation significantly reduced SO2 emissions in the US. Is acid rain still a problem for local ecosystems?

Your study:
In the context of the lab series on local water quality, you will assess the extent to which acid deposition is still a problem in local precipitation and water bodies. You can gain historical context for your data from past ES102 records covering more than a decade.

Implications:
Is acid rain still a problem and if so, what should be done about it? Should we expect to continue to count on current levels of carbon uptake locally?

Context of the problem:
Elevated levels of heavy metals are a problem in the environment because they are toxic to many organisms, including people. Unlike some organic toxins, heavy metals do not degrade but remain in the environment. Recent widely reported health issues include arsenic poisoning of groundwater in Southeast Asia, mercury accumulation in fish which may cause fetal development problems if consumed by pregnant women, and child developmental delays from low level exposure to lead.

In the US in recent years, particular attention has been paid to the problem of lead in the environment. Lead is one of the most useful metals in industrial societies and was used widely in soldering pipes, batteries, ceramic glazes, paint pigments, and gasoline. However, human exposure even at low levels has been linked to delays in neurophysiological development in children and other health problems. Recently, the EPA has stepped up efforts to reduce lead exposure in the environment, banning lead solder in pipes (1986) and requiring greater disclosure of lead paint in older rental properties. Nonetheless, diffuse soil lead remains a problem in many urban areas. For example, in Indianapolis, 15% of urban children have blood lead levels that exceed safe limits. Recent studies have suggested that lead from soils may accumulate at unsafe levels in certain vegetable crops grown in urban community gardens.

In Fall 2003, the Environmental Planning Course (ENVI 302) proposed a series of community gardens on vacant lots in the West Side of Pittsfield. The safety of urban soils in these settings must be evaluated for food production and if lead contamination is found, clean topsoil must be brought in at considerable expense to the project.

Your study:
Are soils in the proposed sites suitable for growing vegetables? Are there unsafe levels of lead in soils of these sites? How do levels of lead in these locations compare with those of soils from non-urban locations like Hopkins Forest?

We will travel to Pittsfield to collect soil samples, analyze soil properties (pH, grain size, organic matter, and exchangeable cations like sodium, potassium, magnesium, and calcium) and measure the lead concentration of soils.

We will also plant some of these soils in the greenhouse to assess the extent to which lead is taken up in different rapid-growing vegetable crops.

Local Water Quality

Context:

Although water covers two thirds of the earth's surface, freshwater that is easily accessible in surface lakes, streams, and rivers represents only 0.01% of all the water available on the planet (97% of water is in the oceans and 2% is in glaciers). The quality of this limited freshwater determines whether it can be used for human needs- for drinking, agriculture, industry, recreation - as well as its ability to sustain healthy ecosystems. Each state sets water quality standards considered safe for these particular water uses (see Massachusetts standards). Waters that do not meet their desired use criteria are considered "impaired".

EPA regulations have made great gains in insuring surface water quality and safe drinking water since the agency was established in 1970. The treatment capacity of municipal sewage treatment systems has doubled, there are now enforced discharge standards for industrial waste, and drinking water standards are now established for 94 contaminants. Still, according to the EPA 30% of the nation's rivers, and 40% of the nation's lakes, do not meet legislatively mandated goals for water quality. Regulation is less able to solve remaining problems like pollutant runoff from agricultural lands and stormwater flows from cities, seepage into ground water from nonpoint sources, and the loss of habitats such as wetlands.

EPA and other agencies are pushing greater local involvement to improve citizen awareness of and involvement in improving water quality. This is carried out with watershed-based initiatives which include local monitoring components, new information technology solutions which enable easy access to information on impaired local water bodies, waste discharges, and other pollution activity on the local scale (sample for the Hoosic watershed). The environmental analysis laboratory at Williams has the capability to measure many of the impairments typical of local water bodies, including pathogens, nutrients, dissolved oxygen, metals, pH, and some pesticides.

Locally, the Hoosic River Watershed Association (HooRWA) has been an active agency for monitoring water quality for the past decade. .

Your study:

Select sites in the local watershed whose water quality you would like to assess. We will collect these samples and make field observations of hydrology, riparian zones, water temperature and dissolved oxygen. In the laboratory we will analyze of total and fecal coliform bacteria, pH and acid-neutralizing capacity, nutrients NO3- and PO4--, and indicator cations (Na+, Ca+).

Since aquatic insects are highly sensitive to water quality, the assemblages of aquatic insects present at a certain site can provide an integrated view of water quality at a site. We will examine aquatic insects assemblages at select sites as well.

Practice and Prospects for Waste Treatment and Remediation

Context:
Sewage waste is volumetrically one of the most significant sources of contamination of surface and groundwaters throughout the world. Disease-causing microorganisms present in sewage may cause a significant human health risk. Excess sewage load can also cause eutrophication of river and lake systems, deteriorating beneficial uses of these water bodies and in some cases altering the mobility of other toxic substances like arsenic.

Waterborne diseases are a major problem in less developed nations. In developed nations, sewage treatment plants and disinfection of drinking water have alleviated the problem of infectious agents in drinking water. However, even in developed countries, in some cities and towns, sewage and storm runoff are connected to the same pipes and sewage treatment system. The additional volume during heavy precipitation events may exceed the capacity of the wastewater treatment plant. If the wastewater treatment plants do not have storage capacity, the incoming water is discharged with less treatment. Conventional sewage treatment plants use intensive bacterial action (typically assisted by energy-intensive stirring or bubbling air into the tanks) to digest sewage, often with chemical methods (chlorination) for final disinfection. "Living Machines" have been proposed as a new alternative approach to treating sewage. These systems also take advantage of microbial communities to digest sewage. However, unlike the "monoculture" soup of bacteria in conventional systems, "Living" sewage treatment systems reestablish a series of diverse ecological communities (plants, aquatic insects, fungi, as well as microbes) which support and enhance the main work of the microbes in breaking down sewage and destroying pathogens. One goal of living systems is to develop a self-sustaining system which does not require external inputs of chemicals.

Mimicking natural systems may also offer options for treating smaller scale and nonpoint source pollution. In many rural areas, older or inappropriately sited septic systems may not offer effective sewage treatment. Agriculture is also a major source of non-point source pollution in lakes and streams in the U.S. Animal production operations have grown larger and more numerous in the US over the last several decades, producing greater volumes of animal waste, which like human waste, may contaminate surface water and groundwater. Advanced conventional wastewater treatment is considered too expensive for the animal waste. Constructed riparian filter strips and constructed wetlands are emerging as potential solutions for these problems.

Your study

We will visit both a conventional sewage treatments system and a "Living Machine" to compare these two approaches. We can make field measurements of temperature, conductivity, and dissolved oxygen at the "Living Machine" and will compare the daily and weekly influent and effluent data on total and fecal coliform bacteria, biological oxygen demand (B.O.D.), NO3- and total suspended solids from both systems.

Integrated solutions

You'll use the EPA's site to identify an impaired waterbody or area near your hometown or other location of interest to you. You'll then present a study you design to assess the origin of the impairment and a proposed solution to remediate the impairment.