Institutional Memory (IM) : Prod Institutional Memory


IM is designed as a reference tool in search of guidance regarding specific dangerous waste issues. Its use is not envisioned to replace Washington (WA) State’s Dangerous Waste (DW) Regulations (Chapter 173-303 WAC). IM includes reference memos, letters and other documents written by the Hazardous Waste and Toxics Reduction staff. These materials are a way to explain regulatory interpretations and to maintain a record of these interpretations.


Read This Disclaimer:

This is a tool for the user to conduct research. Since each regulated site and each set of the circumstances are different; specific documents were . The user is cautioned that the documents they find useful were written to address specific set of conditions which may not match the exact conditions faced by the researcher.

This database, the descriptions this database contains, the document indexing information and the documents cited are not intended to replace the WA State Dangerous Waste Regulations. The database should not be cited or quoted and cannot be relied upon to create any substantive or procedural rights enforceable by any party in litigation with the Washington State Department of Ecology (Ecology).

Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by Ecology and shall not be used for advertising or product endorsement purposes.

Dangerous waste compliance is a site-specific matter and most appropriately handled by your Ecology Regional Office. You should confirm any compliance determinations with your appropriate Ecology Regional office.

Although this database identifies and indexes hundreds of documents, it does not identify and index every dangerous waste document written by Ecology. The plan is to update this database as time permits. Furthermore, some of the correspondence referenced in this database may no longer reflect Ecology’s current regulations or policies. Whenever possible, the database indicates this. It is impossible, however, to indicate every instance of superseded regulations or policies.

Users of the index should also note that the letters and memoranda referenced herein are not by any means a complete representation of the guidance available from Ecology on dangerous waste issues. Database documents are not intended to replace or supersede the regulations and are written in response to very specific site information provided. Users should always consult other sources of information such as the WA State Dangerous Waste Regulations, the Code of Federal Regulations, the Federal Register, Ecology guidance documents and other appropriate guidance documents to ensure complete research.

Documents entered into IM are reviewed for applicability and whether they set forth or support regulations, policies and interpretations to the DW Regulations.

Documents may, at times, be removed for numerous reasons, an example would be a rule change or a document found to be in error.


  • • Advanced search: Use date ranges to narrow search results

  • • Printing: Click view to open document, then print by clicking gear icon at upper right hand corner of your computer

  • • Saving: Click download, open, file, save as (give document a specific name) and save

  • • Searching: Type a word or words into the search field to search for specific information, do not use special characters such as quotes or hyphens

  • • Sorting: Sort columns by clicking on column header


Each document is assigned a unique query index number (Q-index number) which categorizes the document by general topic area and identifies the date the document was written. However, a particular document may cover more than one subject matter or category; therefore the Q-index number will reflect the main topic of that document.

Example: the Q-index number: 3070_101022. This documents deals with the issue of counting dangerous waste toward generator status and the weight of a container. So there are two topics: counting dangerous waste toward the generator status and containers.

How do you read the Q-index number 3070_101022?

  1. The next set of digits, in this case refers to a section in the dangerous waste regulations that covers a topic in the memo; here it would be section WAC 173-303-. Within this section the reader will find the regulations dealing with counting dangerous waste toward generator status. Now, 160 (section -160) could have been chosen because section 160 in the dangerous waste regulations deals with containers. However, counting (section -070) is considered the most relevant topic in that document and therefore 070 is assigned.

  2. The last set of digits in the above example, indicates the date the document was written (year/month/day). Here it would be read as .

Some Q-index numbers may have a descriptor at the end:

Example: 3070_101022, 3070_101022, or 3070_101022. What do these mean?

  1. 3070_101022, means this was a second document written on the same day on the same topic(s).

  2. 3070_101022, means “out dated”. However the document is still important to remain in IM but does not represent Ecology’s most current opinion on a subject matter.

  3. 3070_101022, means “partially out dated” could be for various reasons. For example a rule change in the counting regulations, but the information about containers in the document is still relevant. Use with caution.

  4. 3070_101022, means “historical document”.

  5. Remember to type Outdated (OD), Partially Outdated (PO) or Historical (H) and remember a document is ONLY one of those if stated in the “Keyword(s)” column.

: Q-index numbers followed by a letter descriptor should be used as a “flag” that some of the information in that document may no longer be current, applicable or valid.

Institutional Memory (IM) Version 1.0 | Privacy Policy and Data Disclaimer