Bothell Former Hertz

The southern portion of Bothell Former Hertz (18030 Bothell Way NE lies on Tax Parcel 4 (King County Parcel number 9457200015) south of SR 522. 

Tax Parcel 4 had petroleum and arsenic impacts to ground water that exceeded cleanup levels.  Tax Parcel 4 is under a May 13, 2020 environmental covenant. 

All petroleum contaminated sources have been removed at Tax Parcel 3 and Tax Parcel 4. Groundwater monitoring data collected between 2020 and 2022 shows localized and naturally high arsenic in some groundwater wells, and total petroleum hydrocarbons (TPHs-diesel and heavy oil) are sporadically detected.  The sporadic detections are due to degradation products (polar metabolites) of TPHs in groundwater.  Ecology has determined that the naturally occurring arsenic and petroleum degradation products do not pose any threat to human health and the environment.

Responsiveness Summary now available

The Department of Ecology (Ecology) and the City of Bothell (City) held a 20-day comment period (January 19 - February 7, 2023) to remove the environmental covenant for portions of the Bothell Landing, Bothell Former Hertz, and Bothell Paint & Decorating sites.

Ecology received seven comments regarding removing the environmental covenants for

Bothell Paint and Decorating  (18004 & 18005 Bothell Way N.) - Tax Parcel 3 – King County Parcel # 9457200072.

Bothell Former Hertz (18030 Bothell Way NE) and Bothell Landing (18120, 18126, 18132 Bothell Way NE) - Tax Parcel 4 – King County Parcel # 9457200015.

Ecology has reviewed and considered all the public comments. No significant changes will be made to the environmental covenants.  Ecology will remove the environmental covenants from the respective Tax Parcel 3 and Tax Parcel 4. 

A copy of the termination of the Environmental Covenants will be posted on our website and available at the repositories.

Bothell Former Hertz  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 Bothell Former Hertz Site (also known as Aarenco, or AA Rentals of Bothell) is generally located on both sides of the newly constructed SR 522 roadway, between Bothell Way NE and 98th Avenue NE / NE 180th Street, in Bothell, Washington. The City of Bothell purchased the property in 2009. They entered into an Agreed Order with Ecology in 2011 for investigation of contamination on the site. The property had been developed from 1918 until 2010, when the City of Bothell demolished buildings on the Site for its SR 522 Bothell Crossroads realignment project. Past property use included automobile repair and dealerships, fueling, and equipment rental. Before the property was purchased by the City of Bothell in 2009, it contained a Hertz equipment rental office, storage yard, and equipment repair shop. The property contained a building used as an automobile dealership. A petroleum company is listed as a lessee in 1930. The building included a gasoline dispensing facility with Underground Storage Tanks (USTs). Three USTs were removed from the property in 1993. Petroleum-affected soils were encountered during the UST removals, and an unknown quantity of affected soils remained at the property underneath buildings. 

In 2008, the City of Bothell conducted Phase I and Phase II Environmental Site Assessments (ESAs) at the Site prior to its purchase of this and adjoining properties. The 2008 Phase II ESA included soil and ground water sampling where three former USTs had been removed in 1993. Petroleum hydrocarbons were detected in soil and ground water exceeding state cleanup standards. Vinyl chloride and volatile organic compounds (VOC) were detected at concentrations exceeding state cleanup standards in ground water samples. Other VOCs were detected in groundwater at the time, including common solvents - tetrachloroethene and trichloroethene. The concentrations were below state cleanup standards. The VOC detections in groundwater appear to be from Bothell Service Center Simon & Son Cleanup site, which is being cleaned up separately. Arsenic was also detected in one well above cleanup levels. In summer 2010, Bothell completed an independent cleanup action at the Site to remove approximately 12,000 tons of soils contaminated with mostly oil petroleum hydrocarbons from former underground storage tanks. Some limited remedial investigation was also conducted at that time. Interim action soil cleanups were conducted in 2012 and 2013.

Chemicals of concern remaining in groundwater after the interim action cleanups are:

• Total petroleum hydrocarbons (gasoline, diesel and motor oil range)
• Arsenic
• Halogenated volatile organic compounds (HVOCs), from the adjacent Bothell Service Center Simon & Son dry cleaning site, which is a separate state cleanup site.

Groundwater monitoring data collected between 2020 and 2022 shows localized and naturally high arsenic in some groundwater wells, and total petroleum hydrocarbons (TPHs-diesel and heavy oil) are sporadically detected.  The sporadic detections are due to degradation products (polar metabolites) of TPHs in groundwater.  Ecology has determined that the naturally occurring arsenic and petroleum degradation products do not pose any threat to human health and the environment.

Portions of the BSCSS and the Bothell Former Hertz sites has been re-parceled in the Lot D property, requiring modifications to the monitoring well network and the recirculating bioremediation system. Safeguards are in place to protect residents and workers in the redeveloped property, such institutional controls on land use, vapor barriers and vapor mitigation such as venting to prevent vapor intrusion risks to indoor air quality, and indoor air monitoring. However, since a large mass of contamination has already been removed, any human health risks from remaining contamination in groundwater are considered to be minimal or nonexistent.