MODULE-5 Wastewater Management

Introduction

Wastewater management is critical to protecting drinking water resources. A range of technological approaches may be used to treat and/or dispose of wastewater such as: on-site sewage systems, clustered or shared treatment systems, small wastewater treatment facilities, larger centralized wastewater treatment plants, and innovative and alternative technologies. The figure below presents some of the benefits to rural communities of these wastewater management technologies. The goal of this section is to identify how basic on-site wastewater systems function and to present a range of wastewater management options that can help protect drinking water quality in Washington's rural areas.

Wastewater treatment technologies may be used to improve water quality through additional treatment and/or to allow uses that promote water conservation. Enhanced treatment technologies, which will be discussed later, are often used in aquifer protection areas to reduce the effects of nitrogen and other pollutants on the water supply. Large On-Site Sewage Systems (LOSS), which are used to treat wastewater from more than one user, can often provide enhanced treatment at a lower cost than the traditional septic tank and gravity drainfield.

There are also a variety of wastewater reuse alternatives, such as the use of highly treated effluent for agricultural fields, landscaped areas, and golf courses, which can offer cost-effective and environmentally sensitive solutions to wastewater disposal issues. The re-use of wastewater for activities such as irrigation also reduces dependence on the drinking water supply. Descriptions of many of these technologies suitable for Washington's rural areas are provided in this module. Since conventional on-site sewage systems remain the most common form of wastewater management used in Washington's rural areas, a brief description of their design and implications is provided first.

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