Pollution/Situation Report Profile

Lapwai School District Dry Well
Lapwai, ID - EPA Region X
POLREP #1
Initial

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U.S. ENVIRONMENTAL PROTECTION AGENCY
POLLUTION/SITUATION REPORT
Lapwai School District Dry Well - Removal Polrep
Initial Removal Polrep

EPA Emergency Response

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Region X

Subject:

POLREP #1
Initial
Lapwai School District Dry Well
10LT
Lapwai, ID
Latitude: 46.3963900 Longitude: -116.8043200

To:

From:

Greg Weigel, OSC

Date:

2/7/2013

Reporting Period:

February 4-5, 2013

1. Introduction

1.1 Background

Site Number:	10LT	Contract Number:
D.O. Number:		Action Memo Date:	1/16/2013
Response Authority:	CERCLA	Response Type:	Time-Critical
Response Lead:	PRP	Incident Category:	Removal Action
NPL Status:	Non NPL	Operable Unit:
Mobilization Date:	2/4/2013	Start Date:	2/4/2013
Demob Date:	2/5/2013	Completion Date:
CERCLIS ID:		RCRIS ID:
ERNS No.:		State Notification:	Yes
FPN#:		Reimbursable Account #:

1.1.1 Incident Category
CERCLA Time-Critical Removal Action - RP Lead

1.1.2 Site Description
The Lapwai School District performs maintenance and repair of school buses and equipment at the Bus Transportation and Maintenance facility. The facility contains a building with two repair bays and an office. In June 2012, the EPA Region 10 Underground Injection Control (UIC) Program conducted an inspection at the facility. The inspection identified a floor drain in the bus bay and a drain from a shop sink that emptied into a nearby drywell located underneath an asphalt parking lot next tot he building. In followup to the inspection, the UIC Program required that the school district stop discharging fluids into the drywell, and that the drywell be exposed and sampled. A sample of drywell sludge was collected by the Nez Perce Tribe Water Resources personnel on October 23, 2012. The drywell was reportedly made of concrete blocks and is 4' in diameter and 6' deep, with the top approximately 4' below ground surface.

On December 7, 2012 the school district provided a report with analytical results from the sample taken of the drywell contents. The results show elevated concentrations in the well of chlorinated solvents including tetrachloroethylene at 22.5 milligrams/kilogram (mg/Kg), trichloroethylene at 168 mg/Kg, as well as lead at 1,840 mg/Kg. On the same property within approximately 150 feet of the contaminated drywell is one of two public drinking water supply wells installed and operated by the Bureau of Indian Affairs (BIA). The BIA wells supply drinking water for approximately 300 people in Lapwai, including the Lapwai Elementary School that is adjacent to the school district bus maintenance facility. The BIA wells were recently sampled for volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), including the contaminants found in the drywell, in January 2013. As of that time the BIA wells did not indicated any contamination associated with contaminants in the drywell.

1.1.2.1 Location
The site address is 204 District Road, Lapwai, Idaho. It is within the Nez Perce Reservation. The site is adjacent to the Lapwai Elementary School, and the Lapwai High School is across the street.

1.1.2.2 Description of Threat
TCE and PCE in the drywell present a threat of vertical migration through vadose zone soils to groundwater. Penetration into the aquifer would contaminate a drinking water supply.

1.1.3 Preliminary Removal Assessment/Removal Site Inspection Results
EPA determined that, based on known history of the site, the sample results from the drywell and the proximity to a drinking water supply well and potential exposure to children at the adjacent elementary school, a time-critical removal action to remove contaminated drywell sludge and cleanup associated contaminated soils, was necessary. On January 16, 2013 EPA Region 10 issued a CERCLA Unilateral Administrative Order (UAO) to the Lapwai School District, requiring removal of the drywell contents and the drywell itself, and cleanup of associated contaminated soils. The UAO required characterization and proper disposal of removed and excavated materials, and confirmation sampling and analytical results of remaining soils in the side walls and bottom of the excavation pit.

2. Current Activities

2.1 Operations Section

2.1.1 Narrative
OSC, RP contractor and Nez Perce Tribe mobilized on site Monday, February 4, 2013. Conducted response action and demobilized on Tuesday, February 5, 2013.

2.1.2 Response Actions to Date
On February 5, 2013 RP contractor uncovered drywell and removed sludge-like contents inside drywell into seven 55-gallon drums. Constructed a bermed and lined staging area for excavated soils. Removed the concrete block constructed drywell. Excavated and staged contacting soils that appeared to be contaminated. Soils that appeared to be contaminated were gray in color and showed elevated photo-ionization detector (PID) readings. Continued excavation laterally on 4 sides of a square until appeared to be in "clean" soils, based on visual appearance and PID readings. Continued excavation vertically contaminate soils underneath former drywell. At approximately 12 foot depth the horizon changed from gravels and soils that were probably bedding for the original drywell, to what appeared to be native cobbles, gravels and sands. We continue to excavation at depth to about 14.5 feet in the cobbley material that appeared contaminated. At that depth in soils a PID screening revealed 700 ppm VOCs. The OSC, the Nez Perce Tribe and the School District agreed to excavate no deeper that the 14.5 foot depth because to go deeper would have required significantly enlarging the excavation footprint, and we were limited by proximity to buildings on two sides. We did not want to risk undermining or compromising the integrity of the buildings, and we did not know how deep we would have to go. So, it was agreed to collect cleanup confirmation samples at the 4 sidewalls and excavation bottom at 14.5 feet, and backfill the excavation pit with clean gravel that is visually distinctive from the native material. The final excavation dimensions were approximately 12' by 12' laterally by 14.5' deep. Approximately 30 cubic yards of presumed contaminated soils were removed, along with 7 drums of presumed contaminated sludge from the drywell. Excavated soils were temporarily stockpiled on site, covered and fenced, pending analytical results for hazardous waste characterization and off site disposal.

2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)
Owner and operator of the facility is the Lapwai School District. EPA Region 10 issued Lapwai School District a CERCLA UAO on January 16, 2013, and they agreed to conduct the work required by the UAO.

2.1.4 Progress Metrics

*Waste Stream*	*Medium*	*Quantity*	*Manifest #*	*Treatment*	*Disposal*

2.2 Planning Section

2.2.1 Anticipated Activities
We are awaiting laboratory analytical results of cleanup confirmation samples and waste characterization samples. Anticipate that cleanup confirmation from the excavation bottom will not show that we achieved cleanup goal, so far as vertical extent of contamination. Depending on those results, we will determine next steps.

2.2.1.1 Planned Response Activities
Remove temporarily stockpiled drums (7) and soils (30 cy) for appropriate disposal.

2.2.1.2 Next Steps
See above.

2.2.2 Issues
It could be that after reviewing lab results, we determine that significant contamination was left in place below 14.5 feet depth. If so, additional site investigation will likely be required to better evaluate site geology, hydrogeology and extent of contamination. Such work would require installation of monitoring wells. The Lapwai School District has indicated that they would not have the financial resources to conduct this work.

2.3 Logistics Section