Terrace Heights Elementary School
Site Description
Area-wide soil contamination is defined as contamination above state cleanup levels that is dispersed over a large geographic area. The soil contamination in this case is a result of central Washington’s orchard industry. Much of the region consists of current or former orchard land, where long-term pesticide application has taken its toll. Lead arsenate, a pesticide commonly used between the years of 1905 and 1947 to control the codling moth, has been identified as the primary source of increased lead and arsenic concentrations.
Due to their chemical structure, lead and arsenic tend to bond with soil particles and often remain at or near ground surface level for decades, creating an exposure pathway through inhalation and/or ingestion.
Although lead and arsenic are naturally occurring elements, elevated concentrations have been proven to have a negative impact on human health. Young children are generally more susceptible than adults, which is why Ecology has focused remediation efforts on schools.
In 2007, the site was added to Ecology’s Hazardous Sites List with a ranking of “5”. Sites on the Hazardous Sites List are a priority for Ecology, and have completed a Site Hazard Assessment (SHA). A SHA provides information about the environmental risk of the site. Risk is based on the amount of contaminants, how toxic they are, and how easily they can come in contact with people and the environment. Sites are ranked relative to each other on a scale of “1” to “5”; with a rank of “5” being the lowest.
Cleanup Activities
Cleanup Complete
Based upon cleanup activities, Ecology has determined the site is no longer a threat to human health and the environment. Ecology issued a no further action determination and the site was removed from the Hazardous Sites List in September 2017.
Periodic Review
Periodic review results
Based upon the site visit conducted in March 2021, the clean soil cap on the site continues to reduce the human exposure pathway to contaminated soils to acceptable levels.
The cleanup actions completed at the site appear to be protective of human health and the environment.
Soil cleanup levels have not been met at the site; however, the cleanup action is determined to comply with cleanup standards under WAC 173-340-740(6)(f), since the long-term integrity of the containment system is ensured and the requirements for containment technologies have been met.
The covenant for the property is in place and is effective in protecting human health and the environment from exposure to hazardous substances and the integrity of the cleanup action.
Based on this periodic review, Ecology has determined that the requirements of the environmental covenant are being followed. No additional remedial actions are required by the property owner. It is the property owner’s responsibility to continue to inspect the site to assure that the integrity of the cap is maintained.
Site use restrictions called institutional controls are in effect
Institutional controls can be fences, signs, or restrictions on how the property is used. For instance, an institutional control may prohibit installing drinking water wells or disturbing a protective cap that isolates contamination. These restrictions keep the contamination contained and keep people from being exposed to the contamination. The controls are usually listed in environmental covenants recorded with the county.
Periodic reviews are required when institutional controls are required at a site. Ecology conducts reviews to make sure the controls remain effective and the cleanup still protects human health and the environment. We conduct periodic reviews about every five years.
Institutional Controls 1
Environmental Covenant
Restrictions/Requirements
- Prohibit Soil Disturbance
- Restrict Land Use
Restricted Media
- Soil
Documents 8
Legal 1
Document Title | Document Date | Document Type |
Terrace Heights Elementary Environmental Covenant | 6/17/2015 | Environmental Covenant; Alternative Mechanism |
Public Information 1
Document Title | Document Date | Document Type |
Terrace Heights Elementary School Removal from HSL Fact Sheet | 8/23/2017 | Fact Sheet\Public Notices |
Technical Reports 6
Document Title | Document Date | Document Type |
Terrace Heights Elementary School - Notice of 1st Periodic Review | 3/10/2023 | Site Specific Administrative Document - other (Administrative correspondence) |
Terrace Heights Elementary School 2021 Periodic Review | 5/1/2021 | Periodic Review (5 Year) |
Terrace Heights Elementary School NFA recommendation | 3/1/2016 | Site Specific Administrative Document - other (Administrative correspondence) |
THES Interim Action Report | 12/17/2014 | Interim Action Documents |
Terrace Heights Elementary IRA Plan | 10/29/2012 | Site Specific Technical Document - other |
Terrace Heights Elementary School - Site Hazard Assessment | 1/3/2007 | Site Hazard Assessment Report |
Places to see print documents
-
Central Regional Office1250 W Alder StUnion Gap, 98903-0009Please schedule an appointment to view print documents at this location.
Contaminants 2
Contaminant Type | Soil |
Groundwater |
Surface Water |
Air |
Sediment |
Bedrock |
---|---|---|---|---|---|---|
Metals - Metals Priority Pollutants | RA | |||||
Metals - Arsenic | RA |
- S
- Suspected
- C
- Confirmed Above Cleanup Levels
- B
- Below Cleanup Levels
- RA
- Remediated-Above
- RB
- Remediated-Below
- R
- Remediated