John Newbery Elementary School

The site is located on former orchard property. Soil samples confirmed lead and arsenic area-wide soil contamination above Model Toxics Control Act (MTCA) Method A cleanup levels.

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 1995, 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.

During construction of the school in 1993, the Wenatchee School District conducted an interim remedial action at the site by capping contaminated soils with eight to twelve inches of clean topsoil. Confirmational samples collected from the site following remediation show that all contaminated soils are contained under the clean soil cap.

An environmental covenant was recorded for the property with the Chelan County Assessor. The purpose of the environmental covenant is to provide a permanent legal record of the contamination that remains on the property, and to prevent activities at the site that might disturb or damage the soil cap.

Based upon cleanup activities and the recording of the environmental covenant, Ecology has determined the site is no longer a threat to human health and the environment. Ecology made a no further action determination in August 2010. The site has been removed from the Hazardous Sites List.

Periodic reviews are conducted every 5 years by Ecology for sites that have institutional controls. The review is intended to examine the effectiveness of cleanup activities and to assure the continued protection of human health and the environment.

Periodic review results

Sample data indicates that the clean soil cap on the site continues to reduce the human exposure pathway to contaminated soils to acceptable levels. Based upon a site visit and soil samples collected in September 2013, no repair, maintenance, or contingency actions have been required.

The school has planted a vegetable garden at the base of the slope on the north side of the school. The garden was planted in raised beds that were filled with imported clean soil, which was confirmed by soil samples analyzed during this review. The use of raised beds with clean soil does not allow produce from this garden to come in contact with contaminated soils at the site. School personnel should monitor and maintain this garden area to verify that clean soil in the raised beds does not mix or come in contact with the contaminated soils beneath.

The restrictive covenant for the site was recorded and is in place. This restrictive covenant continues to prohibit activities that will result in the release of contaminants contained as part of the cleanup activities.

Soils with residual pesticide concentrations higher than MTCA Method A cleanup levels are still present. However, the clean soil cap prevents human exposure to residual pesticides by ingestion and direct contact with soils. The environmental covenant for the site will ensure that the integrity of the caps will be protected through restriction of certain activities and maintaining the current use of the site.