Pollution/Situation Report Profile

Twin Falls Mercury
Twin Falls, ID - EPA Region X
POLREP #2
Final POLREP

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U.S. ENVIRONMENTAL PROTECTION AGENCY
POLLUTION/SITUATION REPORT
Twin Falls Mercury - Removal Polrep
Final Removal Polrep

EPA Emergency Response

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Region X

Subject:

POLREP #2
Final POLREP
Twin Falls Mercury

Twin Falls, ID
Latitude: 42.5275632 Longitude: -114.4848996

To:

From:

Richard Franklin, On-Scene Coordinator

Date:

9/30/2009

Reporting Period:

1. Introduction

1.1 Background

Site Number:		Contract Number:
D.O. Number:		Action Memo Date:
Response Authority:	CERCLA	Response Type:	Emergency
Response Lead:	EPA	Incident Category:	Removal Assessment
NPL Status:		Operable Unit:
Mobilization Date:	9/16/2009	Start Date:	9/16/2009
Demob Date:	9/18/2009	Completion Date:	9/30/2009
CERCLIS ID:		RCRIS ID:
ERNS No.:		State Notification:
FPN#:		Reimbursable Account #:

1.1.1 Incident Category

1.1.2 Site Description

On September 15, 2009, a flooring contractor in Twin Falls, Twin Falls County, Idaho, notified local authorities that he had observed what appeared to be mercury in the parking lot of a local apartment complex. The Twin Falls Fire/Hazmat Department and the state's Region 5 Hazardous Materials Regional Response Team (RRT5) responded to the scene and were able to identify and remove a small amount (approximately 1 - 2 teaspoons) of the mercury in the parking lot. The Idaho State Police, Department of Environmental Quality (DEQ) and the Idaho South Central Health District also responded to the incident. EPA mobilied to the site after a request by the Idaho Department of Homeland Security (DHS) and DEQ, and provided air monitoring and technical assistance to local and state authorities. The site is located at the southwestern edge of Twin Falls within a small residential area.

1.1.2.1 Location

1.1.2.2 Description of Threat

1.1.3 Preliminary Removal Assessment/Removal Site Inspection Results

2. Current Activities

2.1 Operations Section

2.1.1 Narrative

2.1.2 Response Actions to Date

    Please see POLREP #1 for detailed history of the site. On September 16, 2009, EPA mobilized to the site and began air monitoring and assessment activities. Interviews with residents and children by the agencies and the South Central Health District revealed that several children in the immediate area had been handling the mercury in the parking lot as far back as March 2009, and may have tracked it into the apartment complex and nearby homes. Some of the mercury was taken it into one residential unit in the complex and spilled in a child's bedroom. The source of the mercury was discovered to have been at least two thermometers that were brought to the apartment complex parking lot by children and broken: once in July 2008 and again in February 2009.

    EPA and the RRT5 conducted air monitoring throughout each of the apartment units in the complex, adjacent empty lots, and in four of five homes of children identified as having played with the spilled mercury. The fifth home was not tested due to refusal of the residents to allow EPA access.  District Health distributed mercury fact sheets to potentially affected children and families. With the exception of the apartment in which the mercury was spilled, and the fifth home, all apartments and homes showed mercury levels well below the 1,000 ng/m3 health-based federal action levels for removal/clean up, and were generally near background levels. However, in the upper bedroom of the unit where mercury was spilled, air monitoring results showed high levels of mercury vapors above the 10,000 ng/m3 level. The residents of this unit were promptly notified and evacuated to a temporary residence provided by the American Red Cross and local Community Services.   EPA bagged up clothing, loose items, and mattresses from the apartment bedroom and removed them to a secure location for later disposal by the Potentially Responsible Party (PRP).  EPA also provided air monitoring data to District and State Health toxicologists for a full assessment of health risks to affected families.

    After meetings were held with the property owner and responding agencies, the property owner immediately hired H2O, a hazmat clean up contractor from Sparks, Nevada, to mobilize to the site to begin assessment and mitigation activities of the apartment complex and parking lot. H2O mobilized to the site on September 19, 2009.
H2O re-evaluated the apartment and, after sealing and heating the bedroom, found very high levels of mercury vapors (up to 50,000 ng/m3). The carpet was removed and bedroom re-heated and vented multiple times. After re-heating and venting, repeated air monitoring with a lumex showed levels of mercury vapors in the bedroom to be below 100 ng/m3. Levels of mercury vapors in the downstairs portion of the apartment was determined to be near background, at 10 - 20 ng/m3. Once evaluation and clean up activities were completed, the residents were allowed to move back in to their apartment.

    In order to finalize site clean up, H2O also addressed the apartment's parking lot, where several areas were previously determined to be contaminated with mercury. H2O drill cored six to seven hot spots, but composite sampling of the cores showed no levels of mercury above federal risk-based levels. The hot spot areas will be seal coated as a temporary measure, but a final remedy will be determined and completed in the near future. All exterior remediation workplans and activities are being conducted under DEQ oversight.

2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)

2.1.4 Progress Metrics

Waste Stream Medium Quantity Manifest # Treatment Disposal

2.2 Planning Section

2.2.1 Anticipated Activities

2.2.1.1 Planned Response Activities

2.2.1.2 Next Steps

Under oversight of DEQ, the property owner's contractor (H20) will evaluate and complete final removal actions of the parking lot. District Health will also conduct follow-up visits with affected families after a full evaluation and risk assessment by state toxicologists. EPA will defer all remaining oversight actions to state and local authorities.

2.2.2 Issues

2.3 Logistics Section