For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report.Suggested reference: Dubrovsky, N.M., Burow, K.R., Clark, G.M., Gronberg, J.M., Hamilton P.A., Hitt, K.J., Mueller, D.K., Munn, M.D., Nolan, B.T., Puckett, L.J., Rupert, M.G., Short, T.M., Spahr, N.E., Sprague, L.A., and Wilber, W.G., 2010, The quality of our Nation's waters-Nutrients in the Nation's streams and groundwater, 1992-2004: U.S. Geological Survey Circular 1350, 174 p. Additional information about this study is available at http://water.usgs.gov/nawqa/nutrients/pubs/circ1350 Library of Congress Cataloging-in-Publication DataThe quality of our Nation's waters : nutrients in the Nation's streams and groundwater, 1992-2004 ForewordThe U.S. Geological Survey (USGS) is committed to providing the Nation with reliable scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov/). Information on the Nation's water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation and is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of that water, now measured in terms of quantity and quality, even more essential to the long-term sustainability of our communities and ecosystems.The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, state, and local information needs and decisions related to water-quality management and policy (http://water.usgs.gov/nawqa). The NAWQA Program is designed to answer: What is the quality of our Nation's streams and groundwater? How are conditions changing over time? How do natural features and human activities affect the quality of streams and groundwater, and where are those effects most pronounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. From 1991to 2001, the NAWQA Program completed interdisciplinary assessments and established a baseline understanding of waterquality conditions in 51 of the Nation's river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/studyu.ht...

The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE) is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993−1994 as part of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from five drinking water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking water wells. At a reporting level of 0.2 μg/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in eight areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in nine areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 μg/L, which is the estimated lower limit of the United States Environmental Protection Agency draft drinking water health advisory. Because MTBE is persistent and mobile in groundwater, it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylene (BTEX) compounds, which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and non-point sources, such as recharge of precipitation and stormwater runoff.

The mission of the U.S. Geological Survey is to assess the quantity and the quality of the earth resources of the Nation and to provide information that will assist resource managers and policy makers at the Federal, the State, and the local levels in making sound decisions. Assessment of water-quality conditions and trends is an important part of this overall mission. The history of the earth sciences demonstrates that the ''scale'' at which scientists examine the Earth has a major effect on the kinds of insights gained from their studies. In geology, for example, roles exist for investigations at the quadrangle map scale (1 :24,000) and for continental or global scale studies focused on plate tectonics. Furthermore, geologic studies at one scale often enhance the understanding of the phenomena examined at the other scales. Similarly, in meteorology, there is a role for microscale climatic studies over distances of less than a mile, mesoscale studies of regional weather systems, and global circulation studies. Again, the overall science would be weakened by the lack of any one of these scales of study. Investigations at different temporal scales also are needed. Some studies of earthquake phenomena, for example, measure processes that last for seconds or even milliseconds, and others chart the buildup of the stresses responsible for earthquakes over periods of decades to centuries. This document defines an approach for examining the quality aspects of water resources at a unique combination of spatial and temporal scales. The spatial scale is primarily regional (several thousands of square miles), and the temporal scale is primarily multiyear and decadal. The study design stems from the view that insights about water quality, which would be of great value to resource managers and policy makers, can be best achieved by examining water quality at these scales and by aggregating the findings of the studies with time and across the Nation. These assessments would rely on many of the data already being collected as part of smaller scale studies focused on local problems, although the questions under investigation would be quite different. The primary questions would concern the natural and human factors that give rise to different types of widespread waterquality conditions and the long-term fate of contaminants stored in aquifers, sediments, or biota. Throughout its history, the Nation has made major investments in assessing natural resources, such as soils, minerals, and hydrocarbons, and human resources in terms of the health, the education, the employment, and the economic status of the population. The reason for these investments in information is that decisions our society makes about using or conserving these resources, investing in their improvement, or regulating their use will be better if they are based on sound information. The maintenance and the improvement of water quality is now one of the major areas of public investment and government regulation. Therefore, it is appropriate that serious attempts be...

A study has been conducted for the past two years on a 4.6 mile stretch of the Saddle River near Lodi, New Jersey. The primary objectives of this study were two fold; initially, the amounts of various heavy metals being contributed to the Saddle River by stormwater runoff, rainfall, and individual tributaries, etc., were investigated to better delineate the distribution of various sources of heavy metals to the aquatic environment. Secondly, a series of benthal deposits from the Saddle River were analyzed to determine the fate of these metals once introduced into the receiving stream. A mass balance analysis of heavy metals in the Saddle River was performed to determine the amount of these materials contributed from unrecorded sources. The results of this study seemed to demonstrate the importance of considering the potential scouring of river sediments as a secondary source of metals in determinations of this type. The distribution of metals in precipitation samples collected in this study was found to be similar to that in runoff, with lead and zinc predominating. Relative concentrations of metals in precipitation as compared to those of stormwater were relatively insignificant. Metal concentrations of bottom sediments were found to vary considerably from sample to sample.

The NAWQA Program recognizes that a national assessment by a single program cannot address all water-resource issues of interest. External coordination at all levels is critical for a fully integrated understanding of watersheds and for cost-effective management, regulation, and conservation of our Nation's water resources. The Program, therefore, depends extensively on the advice, cooperation, and information from other Federal, State, interstate, Tribal, and local agencies, nongovernment organizations, industry, academia, and other stakeholder groups. The assistance and suggestions of all are greatly appreciated.