The Nationwide Urban Runoff Program (NURP) was a research project conducted by the

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...

(EPA) between 1979 and 1983. It was the first comprehensive study of urban stormwater

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, th ...

across the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

Study objectives

The principal focus areas of the study consisted of: * Examine the water quality aspects of urban runoff, and a comparison of results across various urban sites * Assess the impact of urban runoff on overall water quality * Implement stormwater management best practices. A major component of the project was an

analysis Analysis ( : analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (3 ...

of water samples collected during 2,300 storms in 28 major metropolitan areas.

Findings

Among the conclusions of the report are the following: * " Heavy metals (especially

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...

and

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

) are by far the most prevalent priority pollutant constituents found in urban runoff...Copper is suggested to be the most significant hreat/nowiki> of the three." * " Coliform bacteria are present at high levels in urban runoff." * "Nutrients are generally present in urban runoff, but... enerally/nowiki> concentrations do not appear to be high in comparison with other possible discharges." * " Oxygen demanding substances are present in urban runoff at concentrations approximating those in secondary treatment plant discharges." * "The physical aspects of urban runoff, e.g.

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...

and scour, can be a significant cause of habitat disruption and can affect the type of fishery present." * " Detention basins... nd/nowiki> recharge devices are capable of providing very effective removal of pollutants in urban runoff." * " Wet basins (designs which maintain a permanent water pool) have the greatest performance capabilities." * " Wetlands are considered to be a promising technique for control of urban runoff quality." An interesting finding of the NURP was that

street sweeping A street sweeper or street cleaner may refer to a person's occupation or to a machine that cleans streets. Street sweepers have been employed in cities as "sanitation workers" since sanitation and waste removal became a priority. A str ...

was considered to be, "ineffective as a technique for improving the quality of urban runoff".

Impact of the report

In 1987, the results of the report were used as the basis of an amendment to the

Clean Water Act The Clean Water Act (CWA) is the primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters; recognizing the responsibiliti ...

requiring local governments and industry to address the pollution sources indicated by the report. The amendment requires all industrial stormwater dischargers (including many construction sites) and municipal

storm sewer A storm drain, storm sewer ( United Kingdom, U.S. and Canada), surface water drain/sewer ( United Kingdom), or stormwater drain ( Australia and New Zealand) is infrastructure designed to drain excess rain and ground water from impervious su ...

systems, affecting virtually all cities and towns in the country, to obtain discharge permits. EPA published national stormwater regulations in 1990 and 1999. EPA and state agencies began issuing stormwater permits in 1991. ''See'' Stormwater management permits.

About "NURP ponds"

The term "NURP ponds" refers to

retention basin A retention basin, sometimes called a wet pond, wet detention basin, or stormwater management pond (SWMP), is an artificial pond with vegetation around the perimeter and a permanent pool of water in its design. It is used to manage stormwater ...

s (also called "wet ponds") that capture

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...

from stormwater runoff as it is detained, and that are designed to perform to the level of the more effective ponds observed in the NURP studies.For example, see this fact sheet on Wet Ponds published by the Metropolitan Council, St. Paul, MN
"Urban Small Sites Best Management Practice Manual: Wet Ponds."
Some practitioners may assume that a "NURP pond" design conforms to some particular standard issued by EPA, but in fact EPA has issued no regulations or other requirements regarding the design of stormwater ponds. (However, some states and municipalities have issued stormwater design manuals, and these publications may include a reference to a "NURP pond".)

References

{{Reflist, 2

External links

EPA Stormwater Permit ProgramEPA Nonpoint Source Management Program
Stormwater management Water pollution in the United States United States Environmental Protection Agency