[WEBMASTER’S NOTE: These pages are obsolete b ecause all of the changes described below have already been made in the in ternet version of the Handbook.]

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

AUG 19 1994

OFFICE OF WATER

Dear Colleague:

The following material contains the 1994 update to the document Water Quality Standards Handbook - Second Edition. Policy and technical changes to the Handbook are included for Chapters 3 and 4. Changes in Chapters 2, 3 and 7 also correct typographical and editorial errors. The Preface, Glossary, Introduction, and References Sections have been modified to reflect changes elsewhere in the Handbook.
Additions to Chapter 3 include:

• Section 3.6 incorporates EPA's policy on aquatic lif e metals criteria as modified by the Office of Water Policy and Technical Guidance on In terpretation and Implementation of Aquatic Life Metals Criteria (US EPA, 1993f). This policy was signed as the 1993 printing of the Handbook went to press and we promised you revisions to reflect it (p. iv).

• Section 3.7 adds guidance on site-specific aqua tic life criteria as m odified by the Interim Guidance on Determination and Use of Water-E ffect Ratios for Metals (included as new Appendix L), which provides interim guidance c oncerning the experimental determination of water-effect ratios (WERs) for metals and s upersedes all guidance concerning water-effect ratios and the Indicator Species Procedure in USEPA, 1983a and in USEPA, 1984f. It also supersedes the guidance in these earlier doc uments for the Recalculation Procedure for performing site-specific aquatic life criteria modifications.
Conforming changes have al so been made to other Sections of Chapter 3.
Section 4.6 has been added to Chapter 4 and includes guidance on the interpretation of the EPA's antidegradation policy as it relates to nonpoint sources as presented in the guidance memorandum Interpretation of Federal Antidegrad ation Regulatory Requirement (USEPA, 1994a).
Several Appendices have also been added or modified. New Appendix J provides additional material on EPA's policy on aquati c life criteria for metals. New Appendix L adds the Interim Guidance on Determination and Use of Water-E ffect Ratios for Metals. Appendices U and V update the list of EPA Regional water quality standards coordina tors and Standards and Applied Science Division document request forms, respectiv ely. Appendix X has been added as a repository for this and future update instruction sheets so that a record of updates is maintained in the Handbook.

Please follow the instructions on the reverse.

David K. Sabock, Chief Water Quality Standards Branch[WEBMASTER’S NOTE: These pages are obsolete b ecause all of the changes described below have already been made in the in ternet version of the Handbook.]

WATER QUALITY STANDARDS HANDBOOK SECOND EDITION – UPDATE #1

FILING INSTRUCTIONS

Follow the instructions below carefully.

• With the addition of the new Appendices, the Handbook will require two 3- ring binders. Place the Handbook through page REF-6 in a 1" binder and the Appendices in a 3" binder before making the changes below.

• Proceed row by row down the chart following the instructions in both the "REMOVE" and "INSERT" columns for each row.

• Remove the obsolete pages listed in the "REMOVE" column from the Handbook.

• Insert the pages in the "INSERT" column in the appropriate places in the Handbook. These are the new or replacement pages contained in this package.

**SECTION REMOVE INSERT**

**HANDBOOK**

Cover Handbook cover New Handbook cover Title Page Title Page Title Page Preface pp. iii through viii pp. iii through viii Glossary pp. GLOSS-3 through GLOSS-8 pp. GLOSS-3 through GLOSS-8 Introduction pp. INT-7 and INT-8 pp. INT-7 and INT-8 Chapter Table of Contents Chapter Table of Contents Chapter 2 pp. 2-5 and 2-6 pp. 2-5 and 2-6 Chapter Table of Contents Chapter Table of Contents Chapter 3 pp. 3-1 through 3-48 pp. 3-1 through 3-45 Chapter 4 Chapter Table of Contents Chapter Table of Contents pp. 4-7 through 4-13 pp. 4-7 through 4-14 Chapter 7 Chapter Table of Contents Chapter Table of Contents pp. 7-7 through 7-13 pp. 7-7 through 7-13 References pp. REF-1 through REF-9 pp. REF-1 through REF-9

**APPENDICES**

Cover None Document cover for Appendices Appendix J Title Page (reserved) Title Page and new Appendix J Appendix L Title Page (reserved) Title Page and new Appendix L Appendix U WQS Coordinator list WQS Coordinator list Appendix V all pages new Document Request

Forms Appendix W Update Request Form new Update Request Form Appendix X None Title Page and this page of instructions

If you have any trouble with missing pages or have other questions about this update to the Water Quality Standards Handbook, please let us know.