The Rota Power Plant Site is an active diesel-powered electrical plant where contaminated soil and groundwater are present.  The contaminants of concern at the Site are polychlorinated biphenyls (PCBs) in soil and petroleum hydrocarbons in groundwater.  The Site is located in Songsong Village on the island of Rota in the Commonwealth of the Northern Mariana Islands (CNMI). The power plant sits approximately 100 feet from the shoreline of the Philippine Sea. EPA addressed the PCB contamination by excavating the contaminated soil and shipping it off-island for disposal in 2013.  The CERCLA (PCB) portion of the site was completed in July 2013.  This POLREP addresses the OPA portions of the response action, aimed at addressing oil seeping into the ocean.   

Operations at the site include the generation of power for the island of Rota, storage of new and used oil, and oil/water separation. The Rota Power Plant site contains four primary aboveground storage tanks (ASTs) as well as day tanks and drum and transformer storage areas. There are two oil/water separator (OWS) systems are located at the Rota Power Plant site. One rudimentary OWS consists of drums from which oil is manually skimmed. The system is located inside the main Power Plant building and drains to the north of the building into a pit. A second in-ground OWS is piped from the secondary containment areas of the ASTs and the drum storage berm located in the western portion of the property. This OWS can hold 2,500 gallons of oil and water and discharges separated water directly to a pit dug in the ground.
  

MONDAY July 14, 2014:  Personnel on-site: EPA – 1, START – 1, ERRS – 7, APEC - 1.  ERRS continued excavation of the southern interceptor trench 2 and installed the first sump in that segment of trench. Beneath the coral in the area of the sump was a coarse sand, gravel and cobbles and appeared quite permeable. Oil continued to accumulate on the water table in this area, and the pungent, sulfur-like odor was prevalent. In addition, a subcontractor delivered three loads of washed coral to the site for trench pack.  The START collected four stockpile samples and 2 confirmation samples in areas which were no longer being utilized for operations.  ERRS continued overpacking contaminated soil into cubic yard boxes and one container (# 10) was transported off site.  Off site containers were inspected again, as last week there were issues with liquids coming from two containers.  Those containers were brought back to the site soil boxes repackaged, containers cleaned and repacked, and transported off site.  One additional container needed to be addressed, so plans for its return to site were made.  Preparation for demobilization began, with organizing the supplies and beginning to pack the containers for eventual demobe.

TUESDAY July 15, 2014:  Personnel on-site: EPA – 1, START – 1, ERRS – 7, APEC - 1.  Work continued on excavation of the southern interceptor trench, excavating approximately 40 feet.  Loading of contaminated soil into boxes continued and two containers (# 11 and 12) were loaded and transported off site. One additional container was loaded with contaminated soil boxes and prepared for transfer off site the following day.  Preparation for demobilization continued as time was available. 

WEDNESDAY July 16, 2014:  Personnel on-site: EPA – 1, START – 1, ERRS – 7, APEC - 1.  Work continued on excavation of the southern interceptor trench.  Coral in subsurface was competent and oil contamination was less than in the southernmost part of the southern trench. Loading of contaminated soil into boxes continued and one container (# 13) transported off site, while another one was loaded and prepared for off site transfer. The third container that needed to be re-packaged was also on site and there was one box which was leaking and material was re-boxed and container re-loaded for transport.  ERRS began loading the flat rack with shoring.  Preparation for demobilization continued as time was available.  ERRS worked on getting quotes for repair of the CPA/CUC fences.  START collected 2 samples of stockpiles.  Weather patterns brought rain throughout the day.

THURSDAY July 17, 2014:  Personnel on-site: EPA – 1, START – 1, ERRS – 7, APEC - 1.  Work continued on excavation of the southern interceptor trench, including installation of the second sump and completion of the extent of excavation.  In the last 5 feet of the excavation, before needing to stop because of subsurface historic structures, the subsurface changed from competent coral to shellstone, where rock was formed of shells.  Odors increased and oil contamination was more prevalent than in the previous segment.  ERRS began loading washed, crushed coral and 3 loads of coral were delivered in the afternoon.  ERRS also began backfill of the most southern segment where coral had been placed.  ERRS continued loading the first flat rack with shoring after it was decontaminated, and the flat rack was secured and transported off-site.  The second flat rack was then delivered so that the remaining shoring could be loaded.  One container of contaminated soil was moved off site and one empty was brought in its place.  Preparation for demobilization continued as time was available.  .  ERRS also worked on transport of equipment, containers and personnel off island.  START collected 4 samples, one stockpile and 4 confirmation.  Weather patterns brought light rain consistently throughout the day.

FRIDAY July 18, 2014:  Personnel on-site: EPA – 1, START – 1, ERRS – 6, APEC - 1.  The father of one of the ERRS crew passed away this morning, and plans were made to get him home.  Due to the unavailability of any other option, a flight from Rota to Saipan was chartered so that he could leave for the mainland the following day.  Backfill work was completed on the southern interceptor trench and on the recovery trench.  ERRS completed decontamination of the shoring plates and posts and finished loading the second flat rack, which was then transferred off site for shipment to Saipan.  One box of contaminated soil was filled to complete a container and it was prepared for shipment off site.  Grading and restoration of the site began.  All clean soil was used up in the trench excavations.  The vegetation piles were spread along the interceptor trench.  Silt fence along the interceptor trench length was removed.  The air compressor and bull prick were transferred to the port awaiting shipment off island.  Demobilization activities continued.  START shipped 7 samples to the Mainland for analysis.  Weather patterns continued to bring light rain throughout the morning and late afternoon.

SATURDAY July 19, 2014:  Personnel on-site: EPA – 1, START – 1, ERRS – 6, APEC - 1.  16 boxes of contaminated soil were filled with material from the southern trench and cleanup of work areas.  One container (#14) was transported off site, and the other was prepared for pick up on Monday.  ERRS worked on completion, including concreting of the sumps along the interceptor and recovery trenches.  Grading and restoration of the site continued.  START collected 16 confirmation samples.  Demobilization activities continued.        

SUNDAY July 20, 2014:  DAY OFF