Water quality is an important natural resource concern for the Nation. Being a lead natural resource technical agency, the Natural Resources Conservation Service (NRCS) has developed this handbook as a principal reference pertaining to water quality as it relates to all agricultural land uses. The handbook is the principal NRCS reference document for technical information and guidance in carrying out water quality responsibilities. This document consolidates pertinent procedures, guidelines, and other materials to facilitate finding relevant and reliable information. It provides clear guidelines for filing and cross-referencing applicable local, state, and national water quality related reference materials.