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Full-Text Articles in Environmental Health and Protection

National Primary Drinking Water Regulations May 2009

National Primary Drinking Water Regulations

United States Environmental Protection Agency: Publications

NOTES

1 Definitions

• Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.

• Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.

• Maximum Residual Disinfectant Level Goal (MRDLG): The level of a drinking water disinfectant below which there is …


Substrate Monitoring, Contaminant Monitoring, And Educational Outreach On Quagga Mussels (Dreissena Bugensis) In Lake Mead, Nevada, Sara Ann Mueting May 2009

Substrate Monitoring, Contaminant Monitoring, And Educational Outreach On Quagga Mussels (Dreissena Bugensis) In Lake Mead, Nevada, Sara Ann Mueting

UNLV Theses, Dissertations, Professional Papers, and Capstones

The invasive species, the quagga mussel, Dreissena bugensis, was found in Lake Mead, Nevada-Arizona, USA on January 6, 2007. Since then, researchers have been attempting to quantify the amount of damage these mussels will cause to the lower Colorado River basin. Three projects were implemented in this thesis to research the quagga mussel in Lake Mead. First, a study to determine which types of substrates quagga mussels will grow on preferentially was conducted. Six different substrates, Acrylonitrile Butadiene Styrene (ABS) plastic, High Density Polyethylene (HDPE) plastic, Concrete Underlayment Board (CUB), aluminum, stainless steel and fiberglass, were placed in the Boulder …


Estimating The Effects Of Detection Heterogeneity And Overdispersion On Trends Estimated From Avian Point Counts, Matthew A. Etterson, Gerald J. Niemi, Nicholas P. Danz Apr 2009

Estimating The Effects Of Detection Heterogeneity And Overdispersion On Trends Estimated From Avian Point Counts, Matthew A. Etterson, Gerald J. Niemi, Nicholas P. Danz

United States Environmental Protection Agency: Publications

Point counts are a common method for sampling avian distribution and abundance. Although methods for estimating detection probabilities are available, many analyses use raw counts and do not correct for detectability. We use a removal model of detection within an N-mixture approach to estimate abundance trends corrected for imperfect detection. We compare the corrected trend estimates to those estimated from raw counts for 16 species using 15 years of monitoring data on three national forests in the western Great Lakes, USA. We also tested the effects of overdispersion by modeling both counts and removal mixtures under three statistical distributions: …


Low-Level Pharmaceuticals And Personal Care Products In The Waters Of Michigan, Lisa M. Anderson Apr 2009

Low-Level Pharmaceuticals And Personal Care Products In The Waters Of Michigan, Lisa M. Anderson

Dissertations

The results of this research are the product of a two year study funded by the Michigan Department of Environmental Quality with monies from the Clean Michigan Initiative. Low-level (part per billion range) pharmaceuticals and personal care products (PPCPs) in the waters of Michigan were investigated. Five rivers in the State were sampled; including the Clinton, Grand, Kalamazoo, Muskegon, and Saginaw. Groundwater samples were obtained from two shallow municipal water wells also; one on the Grand River and one on the Kalamazoo River. The wells were sampled to determine if PPCPs in the river water were being drawn in by …


Nutrient And Fecal Microbe Sources For A Eutrophic Lake And Recommended Remediation Steps, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar, Jill Hunter, Erin C. Jolly, Richard D. Stockwell Mar 2009

Nutrient And Fecal Microbe Sources For A Eutrophic Lake And Recommended Remediation Steps, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar, Jill Hunter, Erin C. Jolly, Richard D. Stockwell

EKU Faculty and Staff Scholarship

Wilgreen Lake is a man-made lake, classified as nutrient-impaired (303d list) by the EPA and State of Kentucky. The lake drains a watershed with residential developments, cattle pasture, modified woodlands, and some industrial/urban usage in the city of Richmond. The principal tributaries are Taylor Fork and Old Town Branch that meet to form the trunk of the lake approximately one mile in length. The upper reaches of Taylor Fork are adjacent to a densely-packed (quarter-acre lots) housing development with septic systems, and its watershed drains some portions of southern Richmond. Old Town Branch drains cattle pasture and residential areas of …


Mitigation Under Section 404 Of The Clean Water Act: Where It Comes From, What It Means, Palmer Hough, Morgan Robertson Jan 2009

Mitigation Under Section 404 Of The Clean Water Act: Where It Comes From, What It Means, Palmer Hough, Morgan Robertson

United States Environmental Protection Agency: Publications

The requirement to mitigate impacts to wetlands and streams is a frequently misunderstood policy with a long and complicated history. We narrate the history of mitigation since the inception of the Clean Water Act Section 404 permit program in 1972, through struggles between the US Environmental Protection Agency and the US Army Corps of Engineers, through the emerging importance of wetland conservation on the American political landscape, and through the rise of market-based approaches to environmental policy. Mitigation, as it is understood today, was not initially foreseen as a component of the Section 404 permitting program, but was adapted from …


Anthropogenic Osmium In Rain And Snow Reveals Global-Scale Atmospheric Contamination, Cynthia Chen, Peter N. Sedwick, Mukul Sharma Jan 2009

Anthropogenic Osmium In Rain And Snow Reveals Global-Scale Atmospheric Contamination, Cynthia Chen, Peter N. Sedwick, Mukul Sharma

OES Faculty Publications

Osmium is one of the rarer elements in seawater, with typical concentration of ≈10 x 10-15 g g-1 ( 5.3 x 10-14 mol kg-1. The osmium isotope composition (187Os/188Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (≈ 1.3) and mantle/cosmic dust (≈ 0.13). Here, we show that the 187Os/188Os ratios measured in rain and snow collected around the world range from 0.16 to 0.48, much lower than expected (>1), but similar to the isotope composition of ores (approximate to 0.2) …


Metal Concentrations In Native Yupik Foodstuffs From St. Lawrence Island, Alaska, Judith Kricheff Jan 2009

Metal Concentrations In Native Yupik Foodstuffs From St. Lawrence Island, Alaska, Judith Kricheff

Geology Theses and Dissertations

The Yupik people of St. Lawrence Island, Alaska have a traditional subsistence lifestyle with the majority of their diet consisting of local birds, fish, seal, walrus, and whale. Diets based on fish and marine mammals, such as the Yupik diet, are potential pathways for exposure to mercury and other toxic metals. At St. Lawrence Island, metal contaminants may come from local sources such as weathered rock or two abandoned U.S. military bases or remote sources through atmospheric deposition or seasonal migration of animals to the island.
The main goals of this study are to determine the total concentrations of copper …


Geoelectrical Response Of Surfactant Solutions In A Quartzitic Sand Analog Aquifer, Meghan Therese Magill Jan 2009

Geoelectrical Response Of Surfactant Solutions In A Quartzitic Sand Analog Aquifer, Meghan Therese Magill

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this project, the resistivity and phase shift of ten surfactant aqueous solutions in a sand matrix were measured using spectral induced polarization (SIP). In addition, specific conductivity, pH, dissolved oxygen, and dielectric constant measurements of the solutions were also evaluated. The frequency range assessed was 0.091-12000Hz. The surfactants, which are typically used in the remediation of tetrachloroethylene, were Aerosol MA 80-I, Dowfax 8390, and Steol CS-330. The surfactants were mixed into solutions of both deionized and tap water at varying concentrations and injected into a closed system of silica sand. The surfactant treatments altered resistivity, specific conductivity, and pH …


New Book Chapter Reviewing Mojave Desert Revegetation Practices Is Forthcoming, Scott R. Abella Oct 2008

New Book Chapter Reviewing Mojave Desert Revegetation Practices Is Forthcoming, Scott R. Abella

Public Policy and Leadership Faculty Research

I was invited to write a chapter for a forthcoming book on Arid Environments to be published by Nova Science Publishers. This book is anticipated to appear in late 2008 or early 2009, and we will be able to provide additional details about the entire book at that time. I co-authored our chapter on revegetation with Alice Newton, Vegetation Manager at Lake Mead National Recreation Area. We systematically reviewed 23 published studies of planting or seeding native species in the Mojave Desert.


Western Australian Rangeland Monitoring System For Grasslands: Field Manual, Andrew Craig, Philip Thomas Jun 2008

Western Australian Rangeland Monitoring System For Grasslands: Field Manual, Andrew Craig, Philip Thomas

Bulletins 4000 -

Western Australian Rangeland Monitoring System (WARMS) sites are designed to provide defined areas for repeated photography and collection of vegetation composition, shrub/tree cover and landscape function (soil surface assessment) data. This manual defines the procedures for installing and monitoring WARMS sites in the grasslands of northern Western Australia. It provides a documented reference of site stratification at regional scale, and site allocation at station (property) scale. Different procedures apply for sites in the shrublands of the southern pastoral zone. WARMS is designed to be interpreted at the vegetation type or regional scale, rather than lease (station) scale. Information gathered is …


Sustainable Portland: Implementation Series 1, New England Environmental Finance Center Apr 2008

Sustainable Portland: Implementation Series 1, New England Environmental Finance Center

Climate Change

When the Sustainable Portland Task Force Report was released in November 2007, under the leadership of Mayor Jim Cohen, Portland Councilor Kevin Donoghue had the idea that students at the Muskie School of Public Service might be able to help implement recommendations from the report. It may have helped that Kevin was himself a graduate of the Community Planning and Development Master’s program at the Muskie School, but it was a good idea nevertheless. He approached Professor Sam Merrill in the CPD program, who spoke with the new Mayor Ed Suslovic about a possible partnership between the City and the …


Tracing Nutrient Inputs Into A Eutrophic Lake Using Nitrogen Isotopes, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar Apr 2008

Tracing Nutrient Inputs Into A Eutrophic Lake Using Nitrogen Isotopes, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar

EKU Faculty and Staff Scholarship

Wilgreen Lake is a dammed lake that has been classified as nutrient-impaired (303d list) by the EPA and State of Kentucky. The lake is moderately-sized covering 169 acres (0.7 km2), and drains a watershed with residential developments, cattle pasture, modified woodlands, and some industrial/urban usage in the city of Richmond. The principal tributaries are Taylor Fork and Old Town Branch that meet to form the trunk of the lake approximately one mile in length. The upper reaches of Taylor Fork are adjacent to a densely-packed (quarter-acre lots) housing development with septic systems. Old Town Branch drains cattle pasture …


Using E. Coli And Bacteroides Distribution And Abundance In A Eutrophic Lake As A Tracer For Nutrient Inputs, Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski, Alice C. Layton, Larry Mckay Mar 2008

Using E. Coli And Bacteroides Distribution And Abundance In A Eutrophic Lake As A Tracer For Nutrient Inputs, Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski, Alice C. Layton, Larry Mckay

EKU Faculty and Staff Scholarship

Wilgreen Lake is a eutrophic lake that has been listed on the EPA’s 303d list as nutrient impaired. Potential sources of this impairment are likely from humans, cattle manure, and fertilizers. We suspect that the majority of nutrients originate from human sources, namely from septic tank effluent emanating from key housing developments ringing the lakeshore. We test our hypothesis with conventional microbial assays (Escherichia coli) and RT-PCR techniques (Bacteroides).

We took water samples at 19 sampling locations on 4 occasions, and measured the abundance of Escherichia coli using IDEXX methods. Corresponding sub-samples slated for potential PCR …


From Debate To Design: Issues In Clean Energy And Climate Change Law And Policy, Leslie Parker, Jennifer Ronk, Rachel Maxwell, Bradford Gentry, Marijn Wilder, James Cameron Jan 2008

From Debate To Design: Issues In Clean Energy And Climate Change Law And Policy, Leslie Parker, Jennifer Ronk, Rachel Maxwell, Bradford Gentry, Marijn Wilder, James Cameron

Yale School of the Environment Publications Series

A report on the work of the REIL Network 2007-2008


Ua1f Wku Archives Vertical File - Greentoppers, Wku Archives Jan 2008

Ua1f Wku Archives Vertical File - Greentoppers, Wku Archives

WKU Administration Documents

Digitized vertical file materials regarding WKU Greentoppers.


The Balancing Act, David Weaver Jan 2008

The Balancing Act, David Weaver

Conference papers and presentations

Nutrient management is as much a global issue as a local one with a balance required between economics and environment, inherent biological limitations and expectations of nutrient use efficiency, and traditional fertiliser practices and actual enterprise nutrient requirements. The concept of nutrient balance depends on context and scale. Nutrient balance can be considered at a global scale, where issues of nutrient stocks, cycles, depletion and transfer of a particular element are important. For a single farm enterprise, nutrient balance might be considered in terms of phosphorus (P) inputs into and outputs from the enterprise. This is commonly known as a …


Sustainability Of Western Kentucky University: An Examination Of Campus Environmental Policies, Performance And Potential For Change, Christian Ryan-Downing Dec 2007

Sustainability Of Western Kentucky University: An Examination Of Campus Environmental Policies, Performance And Potential For Change, Christian Ryan-Downing

Masters Theses & Specialist Projects

Institutions of higher learning are in a pivotal position to address the environmental problems that global society faces now, but response to this challenge requires transformation in priorities and practices. Recognizing the impacts that universities have on the environment and the social and economic costs associated with these impacts, institutions of higher learning are changing policies and management to become more sustainable. Sustainability is defined by the World Commission on Environment and Development as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs" (1987). To evaluate the environmental impacts …


Fecal Microbe Distribution And Abundance Used As A Possible Proxy For Nutrient Source Identification In Eutrophic Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski Nov 2007

Fecal Microbe Distribution And Abundance Used As A Possible Proxy For Nutrient Source Identification In Eutrophic Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski

EKU Faculty and Staff Scholarship

Wilgreen Lake is a eutrophic lake that has been listed on the EPA’s 303d list as nutrient impaired. Potential sources of this impairment are from humans, cattle manure and fertilizers. We suspect that the majority of nutrients originate from human sources. As a possible proxy for nutrient input, we test our hypothesis by examining fecal microbe distribution and abundance in the lake.

We took water samples at 19 sampling locations on 4 occasions. Sampling spanned 26 June to 15 August with the last 3 sampling events occurring at roughly two-week intervals. These samples were then processed using IDEXX methods, which …


An Update On Groundwater Conditions At The Site Of The York College Cuny Campus In Southeastern Queens County, New York City, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Edward A. Molteni Oct 2007

An Update On Groundwater Conditions At The Site Of The York College Cuny Campus In Southeastern Queens County, New York City, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Edward A. Molteni

Publications and Research

The wells operated by the Jamaica Water Supply Company in Queens represent the only large scale utilization of groundwater for public water supply in New York City in recent years. These wells were shut down, for the most part, beginning in 1996. Since that time, water table elevations in the area, which had been drawn down by the withdrawal activity of the Jamaica Water Supply Company, have risen significantly causing some high groundwater problems, including flooding of basements. The New York City Department of Environmental Protection (NYCDEP) has held public hearings on a contemplated resumption of ground water withdrawal in …


Estimating Business And Residential Water Supply Interruption Losses From Catastrophic Events, Nicholas Brozovic, David L. Sunding, David Zilberman Aug 2007

Estimating Business And Residential Water Supply Interruption Losses From Catastrophic Events, Nicholas Brozovic, David L. Sunding, David Zilberman

Daugherty Water for Food Global Institute: Faculty Publications

Following man-made or natural catastrophes, widespread and long-lasting disruption of lifelines can lead to economic impacts for both business and residential lifeline users. As a result, the total economic losses caused by infrastructure damage may be much higher than the value of damage to infrastructure itself. In this paper, we consider the estimation of economic impacts on businesses and residential consumers resulting from water supply disruption. The methodology we present for estimating business interruption losses assumes that marginal losses are increasing in the severity of disruption and that there may be a critical water availability cutoff below which business activity …


The Whitehead Link On The Cubic Lattice, Elizabeth Haynes Aug 2007

The Whitehead Link On The Cubic Lattice, Elizabeth Haynes

Masters Theses & Specialist Projects

The cubic lattice is a graph in Â3 where the vertices are points with integer coordinates and edges are unit length line segments parallel to the x-, y-, or z-axis. A step is a line segment that connects one vertex to a neighboring vertex one unit away in the x-, y-, or z-direction. This thesis will show that the Whitehead Link needs at least 34 steps to be embedded on the cubic lattice.


Incorporating Results Of Avian Toxicity Tests Into A Model Of Annual Reproductive Success, Richard S. Bennett*, Matthew A. Etterson Jul 2007

Incorporating Results Of Avian Toxicity Tests Into A Model Of Annual Reproductive Success, Richard S. Bennett*, Matthew A. Etterson

United States Environmental Protection Agency: Publications

Modeling the effects of pesticide exposure on avian populations requires knowledge of how the pesticide changes survival and fecundity rates for the population. Although avian reproduction tests are the primary source of information on reproductive effects in the pesticide risk assessment process, current tests cannot provide a direct estimate of the effects of a pesticide on fecundity rates. We present a mathematical model that integrates information on specific types of effects from reproduction tests with information on avian life history parameters, the timing of pesticide applications, and the temporal pattern of pesticide exposure levels to estimate pesticide effects on annual …


Agricultural Contaminant Source And Transport In A Karst Groundwater Basin, Patricia Kambesis May 2007

Agricultural Contaminant Source And Transport In A Karst Groundwater Basin, Patricia Kambesis

Masters Theses & Specialist Projects

Agricultural land use in areas that are located in karst groundwater basins negatively impact groundwater quality because karst terrains provide multiple, direct hydrologic connections from the surface into karst aquifers. The connections and rapid velocities associated with surface and subsurface flow in karst aquifers allow for contaminants to move quickly into and through a groundwater basin. When groundwater returns to the surface via a spring or springs, any contaminants within the water become part of surface streams and rivers. These in turn, impact water quality in areas located downstream of the spring or springs. The purpose of this study was …


Preliminary Results Of A Fecal Microbe Survey In An Eutrophic Lake, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Michael S. Albright Mar 2007

Preliminary Results Of A Fecal Microbe Survey In An Eutrophic Lake, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Michael S. Albright

EKU Faculty and Staff Scholarship

Wilgreen Lake is a small (~14 mi2) eutrophic lake formed by damming several tributary streams to Silver Creek, Madison County, Kentucky. The lake receives runoff from industrial and urban areas (Richmond) that comprise ~10% of the total watershed area; most runoff is from cattle pasture or human developments encircling the lake. Present and past developments are on septic systems, and effluent from these systems is known qualitatively to seep into lake waters.

Our research group is currently conducting a study of the lake in order to identify major nutrient sources, and one possible tracer method is to quantitatively …


Fundulus As The Premier Teleost Model In Environmental Biology: Opportunities For New Insights Using Genomics, Karen G. Burnett, Lisa J. Bain, William S. Baldwin, Gloria V. Callard, Sarah Cohen, Richard T. Di Giulio, David H. Evans, Marta Gómez-Chiarri, Mark E. Hahn, Cindi A. Hoover, Sibel I. Karchner, Fumi Katoh, Deborah L. Maclatchy, William S. Marshall, Joel N. Meyer, Diane E. Nacci, Marjorie F. Oleksiak, Bernard B. Rees, Thomas D. Singer, John J. Stegeman, David W. Towle, Peter A. Van Veld, Wolfgang K. Vogelbein, Andrew Whitehead, Richard N. Winn, Douglas L. Crawford Jan 2007

Fundulus As The Premier Teleost Model In Environmental Biology: Opportunities For New Insights Using Genomics, Karen G. Burnett, Lisa J. Bain, William S. Baldwin, Gloria V. Callard, Sarah Cohen, Richard T. Di Giulio, David H. Evans, Marta Gómez-Chiarri, Mark E. Hahn, Cindi A. Hoover, Sibel I. Karchner, Fumi Katoh, Deborah L. Maclatchy, William S. Marshall, Joel N. Meyer, Diane E. Nacci, Marjorie F. Oleksiak, Bernard B. Rees, Thomas D. Singer, John J. Stegeman, David W. Towle, Peter A. Van Veld, Wolfgang K. Vogelbein, Andrew Whitehead, Richard N. Winn, Douglas L. Crawford

United States Environmental Protection Agency: Publications

A strong foundation of basic and applied research documents that the estuarine fish Fundulus heteroclitus and related species are unique laboratory and field models for understanding how individuals and populations interact with their environment. In this paper we summarize an extensive body of work examining the adaptive responses of Fundulus species to environmental conditions, and describe how this research has contributed importantly to our understanding of physiology, gene regulation, toxicology, and ecological and evolutionary genetics of teleosts and other vertebrates. These explorations have reached a critical juncture at which advancement is hindered by the lack of genomic resources for these …


Preliminary Results Of A Nutrient Source Study In Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Erin C. Jolly Nov 2006

Preliminary Results Of A Nutrient Source Study In Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Erin C. Jolly

EKU Faculty and Staff Scholarship

Wilgreen Lake (Madison County, Kentucky) is an eutrophic lake formed by damming Taylor Fork, part of the Silver Creek watershed. Two principal tributaries drain urban areas of the city of Richmond, agricultural land typified by cattle grazing, and a high-density residential area using septic systems. The lake is “nutrient impaired,” so it is likely that anthropogenic nutrient loading is affecting water quality. Our study aims to first characterize the physical characteristics and water quality of the lake (2006), and then determine the specific proportion of nutrient inputs (2007) to the lake with the aim of remediating any possible degradation of …


On The Spatial Nature Of The Groundwater Pumping Externality, Nicholas Brozovic, David L. Sunding, David Zilberman May 2006

On The Spatial Nature Of The Groundwater Pumping Externality, Nicholas Brozovic, David L. Sunding, David Zilberman

Daugherty Water for Food Global Institute: Faculty Publications

Most existing economic analyses of optimal groundwater management use single-cell aquifer models, which assume that an aquifer responds uniformly and instantly to ground- water pumping. This paper demonstrates how spatially explicit aquifer response equations from the water resources engineering literature may be embedded in a general economic framework. Calibration of our theoretical model to published economic studies of spe- cific aquifers demonstrates that, by averaging basin drawdown across the entire resource, existing studies generally understate the magnitude of the groundwater pumping external- ity relative to spatially explicit models. For the aquifers studied, the drawdown predicted by single- cell models may …


Unlv Magazine, Carol C. Harter, Joe Cockrell, Tony Allen, Regina Bacolas, Lori Bachand, Jennifer Lawson, Bret C. Birdsong, Steve Parker, Erin O'Donnell, Jennifer Robison Apr 2006

Unlv Magazine, Carol C. Harter, Joe Cockrell, Tony Allen, Regina Bacolas, Lori Bachand, Jennifer Lawson, Bret C. Birdsong, Steve Parker, Erin O'Donnell, Jennifer Robison

UNLV Magazine

No abstract provided.


Optimal Management Of Groundwater Over Space And Time, Nicholas Brozovic, David L. Sunding, David Zilberman Jan 2006

Optimal Management Of Groundwater Over Space And Time, Nicholas Brozovic, David L. Sunding, David Zilberman

Daugherty Water for Food Global Institute: Faculty Publications

For nearly half a century, groundwater has been portrayed in the economic literature as a typical common property resource. Numerous studies of groundwater extraction have analyzed the externalities imposed by users on each other. A large body of work offers clear prescriptions in the form of optimal policy instruments, and a similarly large body of work advocates the needlessness of any centralized intervention. Yet existing theoretical models of groundwater extraction implicitly make two strong assumptions about the underlying behavior of the resource. First, the spatial distribution of resource users is assumed to be irrelevant. Second, path-independence of the resource is …