2.1.1 Narrative
2.1.2 Response Actions to Date
Week of May 9th
ERRS mobilized a small crew to begin demolishing various concrete structures on May 9th, 2016, in order to begin excavation activities on May 16th. They also began Site setup - office trailer, power drops for the mobile lab, etc. START was on Site for two days on May 10th and 11th to establish the sampling/excavation grid and obtain samples from the first lift, which were analyzed in the lab in Denver prior to mobilization. OSC Sandoval was on Site for this period of time.
Week of May 16th
OSC Myers, along with the remainder of the ERRS crew and 3 START contractors, mobilized to the Site on May 16th. START set up the mobile lab that evening in preparation to begin receiving and analyzing samples to guide ERRS excavation efforts. START sampled excavated areas as each grid was completed (see attached grid map) to guide excavation and waste segregation activities in order to minimize the amount of soil requiring treatment.
ERRS continued to break out concrete and began excavation efforts during this time frame. As ERRS demolished the former refinery foundation (see the maps in the START 3 Sampling Activities Report), the crew discovered that six small equipment pads, visible on top of the foundation structure, were actually six very large, heavily reinforced concrete structures extending well below what was believed to be native grade. These structures were estimated to weigh approximately 100,000 pounds each, and may have to be moved if the excavation depth exceeds eight feet. Excavation efforts were slower than anticipated during this time period due to some challenges removing various concrete structures and sorting contaminated debris from clean debris. The majority of the first two excavation lifts of rows 2 through 7 in columns B, C, and D were completed during this week, and graphical depictions of the excavated lifts are available in the documents section of OSC webpage for the Site.
Week of May 23rd
Excavation lifts 3 and 4 were completed during this period. Excavated areas were generally in grid rows 2 through 7 in columns B and C. Cell E5 was also excavated down to the 2nd lift elevation.
A demolition company evaluated the large concrete structures mentioned previously, and offered a quote to demolish them. The quote was nearly double the IGCE, and would not have been completed before June 1st. As an experiment, one excavator was configured with the breaker attachment and one of the structures was broken into pieces manageable with equipment on Site. From this test, the crew found that they could break up the structures before the demolition company could be on Site. This did slow down excavation during the week, and will likely extend the excavation phase of the project by a week.
START began conducting personal and area air sampling as the crew encountered high levels of PCP in soils. Results from initial rounds of sampling are all non-detect.
Week of May 30th
OSC Sandoval was on Site for this period. Excavation lifts 5 through 8 were completed during this period. Removed source contamination through lift 11. Cells C4 through C7 required the deepest excavation. Removed all concrete structures mentioned above and around the pad structure. Began re-grading the entire treatment cell to lift 2. Screen arrived on Site late Thursday, which will be used to remove debris from the sawdust piles that will be used for the treatment cell mixture, as well as removing larger rocks and debris from the contaminated soil prior to treatment. Ran a second round of air monitoring samples for the perimeter and cabin in the excavator. All air sample results to date have been non-detect. Air sampling has been discontinued.
Week of June 6th
OSC Myers was on Site from June 6th through June 10th. The excavation was largely backfilled and compacted during this period, and a large majority of the excavated soils were amended with sawdust in preparation for treatment. A local irrigation firm was on Site to discuss potential irrigation solutions for the treatment phase this fall. The OSC and START demobilized for the weekend.
Week of June 13th
OSC Sandoval was on Site intermitantly this week. START remobilized with a project team leader and chemist to support excavation activities in the southern area of the Site. Activities during this week generally consisted of backfilling/compacting the northern excavation, pressure washing and cutting up steel found in the excavation. Excavation of rows 8-11 began mid-week.
Week of June 20th
OSC Romero was on Site from June 20th through June 24th. Excavation and sampling continued throughout on grids A8, A10, A11, C8, B9, C9,and D9. Approximately one thousand cubic yards of contaminated soils were excavated and moved to the stockpile area for later bioremediation. Additional grids (AA7 - AA10) were created to track excavation under the secondary drip pad. This drip pad consisted of a metal frame and pad 1.5 - 2 feet above ground level and approximately 120 linear feet in length. The metal from the drip pad was pressure washed per 40 CFR 268.45 process for hazardous debris to remove any residual contamination, cut up, and will be recycled as processed scrap metal. All excavation was considered complete per the terms of the Action Memorandum as of COB Saturday, June 25, and the crew began preparing the treatment cell.
Week of June 27th
OSC Myers was on Site this week. All remaining excavated soil was spread into the treatment cell during this period. A map of the final cell boundaries is available on the OSC website. Crews also tilled the cell to mix and loosen the soil after being tracked on, applied the required nutrient mix, and applied approximately 1/2 to 3/4 rain equivalent inches of water to the cell. All EPA, START, and ERRS resources demoblized from the site on July 1st. See Planning Section for more details.
2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)
EPA is evaluating available enforcement options.
2.1.4 Progress Metrics
Waste Stream |
Medium |
Quantity |
Manifest # |
Treatment |
Disposal |
Excavated Contaminated Soil |
soil |
estimated 6597 cubic yards |
N/A |
biological degradation, pending |
N/A |
Contaminated Debris |
concrete/steel |
180 cubic yards |
N/A |
high temperature/pressure wash complete. |
Steel-recycled.
Concrete - on-site disposal
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