EPA 841-B-95-002
April, 1995

When More Is Better

The recognition of diffuse, or nonpoint source, pollution as a major contributor to declining water quality has spawned another approach to improving our water resources: better water quality through greater water quantity.

This document explains the relationship between the quantity of water and its quality and discusses how developing water-use efficiency programs can help states and local communities achieve cleaner water through conserving water.

Introduction
Ch. 1 - How We Use Water In These United States
Ch. 2 - How Excessive Water Use Affects Water Quality
Ch. 3. - How to Conserve Water and Use It Effectively
Ch. 4 - Regional Approaches to Efficient Water Uses: Tales From the Trenches
Glossary and References

Introduction

Typically, nonpoint source (NPS) pollution originates from rain and melted snow flowing over the land, which is called runoff. As runoff contacts the land's surface, it picks up many pollutants in its path_sediment, oil and grease, road salt, fertilizers, pesticides, nutrients, toxics, and other contaminants. Runoff can also originate from irrigation water used in agriculture and on landscapes. Many pollutants are picked up by irrigation water as it runs off the land.

Water conservation coupled with pollutant source reduction, such as nutrient and pesticide management, would be a particularly effective approach to reducing the adverse effects of all types of NPS pollution. The focus of this document, however, is on the types and sources of NPS pollution most commonly associated with urban uses of water.

Other types of nonpoint pollution include changes to the natural flow of water in stream channels or wetlands. Changes to the natural flow of water in streams or wetlands result in habitat destruction for fish and wildlife. Placing dams across our rivers and streams can permanently alter the characteristics of upstream and downstream areas by flooding upstream habitats and drying downstream habitats. Failures of onsite disposal systems (septic tanks) lead to increases in nutrients, harmful bacteria in oyster and clam beds, and closures of public swimming areas. Conserving water can help to reduce some impacts from these other sources of nonpoint pollution.

Perhaps most relevant, however, besides the intrinsic benefit of improving water quality by addressing water quantity, are the other, economically beneficial effects of these water quality improvements. Some of the NPS pollution problems that can be reduced by improved water conservation include:

• On-site disposal system failures
• Dried-up downstream wetlands
• Polluted runoff from overirrigation of agricultural and urban lands
• Construction of additional dams and reservoirs and additional water and wastewater treatment facilities
• Surface water withdrawals that result in habitat degradation both instream and on land adjacent to streams and lakes (riparian areas)

The many benefits of water use efficiency include cost savings and pollution prevention even beyond nonpoint source pollution because many pollution prevention practices and activities result in reduced water use, which saves money. However, some pollution prevention practices that do not reduce NPS pollution also provide a cost savings, making these three driving forces (water use efficiency, cost savings, and pollution prevention) great companions. The umbrella term "water use efficiency" actually defines a larger area of two subcategories: water conservation_finding ways to use less water to begin with_as distinct from water reuse and reclamation, such as "closed loop cycles" to reuse water in commercial and industrial settings or use of partially treated wastewater for lawn watering and in industrial settings.

Implementing practices or programs outlined in this guide might help reduce onsite disposal system failures and decrease runoff of nutrients and soil from landscaped areas or agricultural fields. By reducing septic system failures and conserving irrigation water, we can also protect ground water from nitrates and salinity to preserve and safeguard our drinking water supplies.

Similarly, saving water through improved efficiency can lessen the need to withdraw ground or surface water supplies for municipal or industrial demands. Conserving water decreases the need to impound or otherwise regulate the natural flow of streams, thus preserving free flow to retain the value of stream and river systems as wildlife habitat and for tourism and recreation.

In addition, building fewer and smaller new water projects can help prevent the destruction or degradation of pollutant-filtering wetlands. Efficient water use can also mean a reduction in the amount of energy needed to treat wastewater, resulting in less energy demand and therefore fewer by-products from power plants.

The reuse of wastewater or reclaimed water is beneficial because it reduces the demands on available surface and ground waters. Also, recycling process water can reduce industrial pollutants discharged into lakes, streams, rivers, and oceans. Perhaps the greatest immediate benefit of establishing water reuse programs is their contribution to delaying or eliminating the need to expand potable water supply and treatment facilities. However, sometimes this reuse can also adversely impact waters. Highest quality water sources are preserved for drinking water by using treated wastewater for other uses (USEPA, 1990e).

Water conservation is not a new idea in the United States. In fact, more than 40 states now have some type of water conservation program. Nationwide surveys already indicate more than 80 percent of water utility customers support some form of water conservation measure (Kranzer, 1988). Water suppliers and consumers can choose from a wide variety of available water conservation practices, programs, and strategies proven capable of significantly reducing water consumption. These include:

• Metering
• Reducing water pressure
• Imposing water use restrictions
• Enacting zoning ordinances
• Changing price structures
• Educating the public

This document is designed to serve as both resource and guide for state and local officials, particularly where water conservation is determined to be an important consideration in protecting water quality. A Guide to Cleaner Water Through Conserving Water begins with a review of water use in the United States, showing trends in major categories of water use. The second chapter outlines a variety of nonpoint pollution impacts resulting from excessive water use, and the third chapter describes some of the technical and programmatic approaches available to reduce water use and thus protect water quality. The fourth chapter provides a number of examples of regional programs implementing many of these approaches. The document concludes with a glossary and references to aid in understanding the material.

Proceed to Chapter 1

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