Facility Site ID: 93061 Cleanup Site ID: 14970

  • Site Status

  • Cleanup Started

Public Comment Period November 21, 2022-December 22, 2022

Last Updated: 11/15/2022

Ecology and the City of Bothell are moving forward with the cleanup of the Bothell Riverside HVOC Site in the downtown Bothell area. This Site is one of six sites in the historic downtown area that have received grant funding from Ecology to help with the cost of cleanup. 

The following Riverside HVOC documents are ready for public review:
 
Agreed Order (AO) 
A legal agreement between Ecology and the City requiring the City to investigate the contamination, share different methods for cleaning it up, and create a draft cleanup plan for Ecology’s selected cleanup method.

Supplemental Remedial Investigation/Feasibility Study (RI/FS) 
A description of the nature and extent of the contamination, evaluation of other ways to clean up the Site, and a recommendation of a preferred remedial alternative.

Draft Cleanup Action Plan (dCAP): (pg.26 of the Agreed Order)
A description of Ecology’s selected cleanup action and the specific cleanup standards for the Site.

Comment online. Comment using email.
Sunny.Becker@ecy.wa.gov
Mail your comment.
Sunny Becker
Department of Ecology - TCP
PO Box 330316
Shoreline, WA 98133-9716 

View a digital version of the November 2022 community mailer. 

If you would like to be added to the mailing list or email list for this site, contact Meredith Waldref

Site Background

The Bothell Riverside HVOC (Halogenated Volatile Organic Compounds) Site is generally located at NE 180th Street & Woodinville Drive (SR 522) in Bothell. Originally, this Site was considered an “area” within the overall Riverside Site.  

Operations at a former machine maintenance shop are believed to have caused HVOC contamination to enter groundwater in the HVOC area at cleanup levels higher than allowed under the Model Toxics Control Act (MTCA).

In 2009, Ecology and the City of Bothell entered into an Agreed Order to conduct investigations, develop cleanup alternatives, and perform interim cleanup actions at this site. Investigations found chlorinated solvents in groundwater in the HVOC area and petroleum contamination in the soil in the TPH area. The areas were then split into two cleanup sites.

In 2013, Ecology and the City agreed to amend the 2009 Agreed Order so that the City could conduct an interim cleanup action to prevent the chlorinated solvents from discharging into the Sammamish River. The City installed six extraction wells to collect solvent-contaminated groundwater and treat and discharge it into the sanitary sewer.

In 2019, Ecology negotiated a new Agreed Order with the City for the Bothell Riverside HVOC Sites. This new order replaced the existing 2009 Agreed Order for the original larger Bothell Riverside Site.


Site Investigation And Proposed Cleanup

Proposed cleanup actions at the Bothell Riverside HVOC site.
Proposed cleanup actions at the Bothell Riverside HVOC site.
Remedial Investigation and Feasibility Study
HVOC-impacted soil exceeding MTCA cleanup levels range from 12 to 30 feet below ground surface. HVOC-impacted groundwater exceeding MTCA cleanup levels is present at depths less than 15 feet below ground surface.  Impacted soil and groundwater were found to be suitable for mass removal through soil vapor extraction and bioremediation.

Proposed cleanup
A soil vapor extraction system will be installed in the source area.  In addition, a bioremediation and groundwater recirculation system will be installed to treat HVOC contamination in the groundwater.  The contaminated groundwater will be treated and discharged back into the ground.  Once the bioremediation/recirculation system is fully operational, none of the treated groundwater is anticipated to be discharged to the sanitary sewer system. More details of the proposed cleanup can be found on page 40-44 of the dCAP.
Riverside HVOC Site location.
Riverside HVOC Site location.
Legal 8
Document Title Document Date Document Type
Agreed Order Public Comment 10/20/2022 Agreed Order
Bothell Riverside HVOC - Agreed Order - December 2019 12/5/2019 Administrative Order on Consent
Bothell Riverside TPH - Agreed Order - October 2019 10/21/2019 Agreed Order
Bothell Riverside HVOC - Agreed Order - October 2019 10/21/2019 Agreed Order
Bothell Riverside - Amended Agreed Order 2013 2/1/2013 Agreed Order Amendment
Riverside Property NFA determination letter assoc. with LUST Site #2241 5/4/2012 NFA Letter – non-VCP
Bothell Riverside - Amended Agreed Order 2010 6/9/2010 Agreed Order Amendment
Bothell Riverside- Final Agreed Order 3/27/2009 Agreed Order
Public Information 12
State Environmental Policy Act 5
Technical Reports 25
Document Title Document Date Document Type
supplemental Remedial Investigation/Feasibility Study 2/22/2022 Remedial Investigation / Feasibility Study
Final Interim Action Report 12/31/2019 Interim Action Documents
Riverside Memo Additional soil and groundwater Sampling 11/9/2018 Remedial Investigation / Feasibility Study
Riverside HVOC area FS 2 7 18 2/7/2018 Remedial Investigation / Feasibility Study
Bothell Riverside TPH Final FS Report 12/18/2017 Feasibility Study
Bothell Riverside TPH Final CAP 12/18/2017 Cleanup Action Plan
Bothell Riverside - Final RI Report 12/18/2017 Remedial Investigation Report
Riverside HVOC GW Rpt Year 4, Quater 3 12/2/2017 Groundwater Monitoring Report
Riverside Soil Excavation Rpt 5 5 17 NO APP B_C 5/5/2017 Remedial Action Report
Riverside GW mon YR3-QTR4 (IA#2) 4/13/2017 Groundwater Monitoring Report
Riverside GW mon YR3-QTR4 (IA#2) 1/26/2017 Groundwater Monitoring Report
Riverside GW mon YR3-QTR3 (IA#2) 11/10/2016 Groundwater Monitoring Report
Riverside IAWP (second excavation in the TPH area) 10/12/2016 Remedial Investigation Work Plan
RiversideHVOC GW mon YR3-QTR2 (IA#2) 9/2/2016 Groundwater Monitoring Report
SOIL GAS SURVEY/ SOURCE INVESTIGATION 2/26/2016 Remedial Investigation / Feasibility Study
GROUND WATER MONITORING RESULTS YEAR 2, QUARTER 4 - DECEMBER 2015 1/25/2016 Groundwater Monitoring Report
Bothell Riverside - Interim Action Work Plan HVOC 2013 1/7/2013 Site Specific Technical Document - other
Interim Action Work Plan - Bothell Riverside 4/30/2010 Interim Action Documents
Safety and Health Plan - Bothell Riverside 2/28/2010 Health and Safety Plan
City of Bothell Response to Ecology's Opinion Review Letter dated 1/12/10 1/29/2010 Site Specific Administrative Document - other (Administrative correspondence)
Bothell Riverside Ecology's Opinion Review Letter on RI/FS Report and DCAP 1/1/2010 Site Specific Administrative Document - other (Administrative correspondence)
Bothell Riverside RI/FS Work Plan Amendment and Approval 8/18/2009 Engineering Design Report
Bothell Riverside RI/FS Work Plan 7/8/2009 Remedial Investigation Work Plan
Bothell Riverside - Site Hazard Assessment 6/22/2009 Site Hazard Assessment Report
City of Bothell Multi Site Health and Safety Plan 2/25/2009 Human Health and/or Eco Risk Assessment
There may be more documents related to this site. To obtain documents not available electronically, you will need to make a public records request.

Places to see print documents

  • Northwest Regional Office
    15700 Dayton Ave N
    Shoreline, 98133
    Please schedule an appointment to view print documents at this location.
  • Bothell City Hall
    18415 101st Ave NE
    Bothell, 98011
    This location may only have print documents available during open comment periods.
  • King County Bothell Regional Library
    18215 98th Ave NE
    Bothell, 98011
    This location may only have print documents available during open comment periods.

Contaminants 1

Contaminant Type
Soil
Groundwater
Surface Water
Air
Sediment
Bedrock
Halogenated Organics - Halogenated Solvents C C
S
Suspected
C
Confirmed Above Cleanup Levels
B
Below Cleanup Levels
RA
Remediated-Above
RB
Remediated-Below
R
Remediated
This contaminant list was based on our best information at the time it was entered. It may not reflect current conditions at the site.