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 agency of the United States government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on De ...

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

stormwater Stormwater, also written storm water, is water that originates from precipitation (storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed lan ...

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

across the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Study objectives

The principal focus areas of the study consisted of: * Examine the

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

aspects of

urban runoff Urban runoff is surface runoff of rainwater, landscape irrigation, and car washing created by urbanization. Impervious surfaces (roads, parking lots and sidewalks) are constructed during land development. During rain, storms, and other Precipitati ...

, 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 (38 ...

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 upright=1.2, Crystals of lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals is a controversial and ambiguous term for metallic elements with relatively h ...

(especially

copper Copper is a chemical element; it has symbol Cu (from Latin ) 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 pinkish-orang ...

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

and

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It 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 periodic tabl ...

) 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 Coliform bacteria are defined as either motile or non-motile Gram-negative non- spore forming bacilli that possess β-galactosidase to produce acids and gases under their optimal growth temperature of 35–37 °C. They can be aerobes or ...

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 Secondary treatment (mostly biological wastewater treatment) is the removal of Biodegradation, biodegradable organic matter (in solution or suspension) from sewage or similar kinds of wastewater. The aim is to achieve a certain degree of effluent ...

plant discharges." * "The physical aspects of urban runoff, e.g.

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

and scour, can be a significant cause of habitat disruption and can affect the type of fishery present." * "

Detention basin A detention basin or retarding basin is an excavated area installed on, or adjacent to, tributaries of rivers, streams, lakes or bays to protect against flooding and, in some cases, downstream erosion by storing water for a limited period of time. ...

s... 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 A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

are considered to be a promising technique for control of urban runoff quality." An interesting finding of the NURP was that street sweeping 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 primary respo ...

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, United States, U.S. and Canada), highway drain, surface water drain/sewer (United Kingdom), or stormwater drain (Australia and New Zealand) is infrastructure designed to Drainage, drain excess rain an ...

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 retention pond, wet detention basin, or storm water 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 ...

s (also called "wet ponds") that capture

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

from

stormwater runoff Surface runoff (also known as overland flow or terrestrial runoff) is the unconfined flow of water over the ground surface, in contrast to '' channel runoff'' (or ''stream flow''). It occurs when excess rainwater, stormwater, meltwater, or other ...

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