On 7/21/11 at 1934 hrs, an explosion occurred in a tanker truck parked at a truck stop (Travel America) at Exit 12 off of I-94 in Sawyer, Michigan.  The tanker truck was transporting an estimated 4,600 gallons of a mix of approximately 86% water, 13% Sodium Hydroxide, and 1% Methyl Ethyl Ketone (MEK).  The explosion occurred due to the buildup of hydrogen gas produced from a reaction between the sodium hydroxide and the aluminum tanker.  As a result of the explosion, the contents of the tanker were released into a storm drain sewer along Sawyer Road in Sawyer, Berrien County, Michigan.  The storm sewer discharges to Deer Creek, a tributary to Lake Michigan.  The responsible parties, Marcus Trucking and Clean Harbors, are conducting cleanup operations under the oversight of the Chikaming Fire Department, local (Berrien County) and state government (MDEQ) officials, and USEPA.

The impacted Deer Creek is approximately 1.25 miles long.  Contractors have created two earthen berms in between the release point and Lake Michigan.  The first berm is located at the discharge of the sewer into Deer Creek just north of Sawyer Road.  The second berm is located on the east side of Tower Hill Road and just north of Gandy Lane.  

Current Activities

During the reporting period, the PRP continued vacuuming impacted areas of the creek with high pH (near earthen berms).  A third berm, constructed with sheet piling, was installed where Deer Creek crosses Ravenswood Lane.  USEPA, START, and MDEQ continued monitoring the pH along Deer Creek and at the confluence with Lake Michigan.

On the morning of 7/23/2011, the Conservation Officer reopened the beach at Warren Dunes State Park based on neutral pH readings recorded by USEPA, START, and MDEQ personnel.  Warren Dunes State Park is located approximately 1.1 miles north of where Deer Creek empties into Lake Michigan.   

On 7/23/2011 at approximately 0900 hours, personnel observed a fish kill (including sucker and sunfish) on Deer Creek downstream of the second berm.  pH readings observed in these areas ranged from 9.6 to 11.1 standard units (SU).  Clean Harbors neutralized areas of Deer Creek with high pH using vinegar, as approved by MDEQ.

On 7/23/2011 at approximately 1400 hours, START and USEPA conducted monitoring of puddles on Sawyer Road and inside the storm sewers along Sawyer Road.  pH readings of the puddles ranged from 8.2 to 9.5 SU, with the exception of on pH reading of 11.4 SU located further east near the spill site.  pH readings of water inside the storm sewers ranged from 7.6 to 9.6 SU, with the exception of the two catch basins located furthest east near the spill site which had pH readings of 10.35 and 13.73 SU.  Clean Harbors vacuumed out the two catchbasins and power washed the road in these areas.  
 

START and USEPA also measured the pH of the standing water at the outflow pipe in the vegetated area near the I-94 off-ramp.  pH at this location was 10.5 SU.  Clean Harbors vacuumed out water with high pH in this area and neutralized the area with vinegar.  Final pH readings were observed at 7.6 SU (on 7/24/2011).

On 7/23/2011 at approximately 1830 hours, USEPA received an inquiry from a nearby resident with a private drinking water well regarding the quality of the drinking water.  USEPA and START collected a pH reading of 7.57 SU at the outside spigot indicating drinking water that is safe for consumption.

On 7/23/2011 at approximately 2030 hours, Clean Harbors began pumping water over the berm at Tower Hill Road based on pH readings up stream below 9 SU.  USEPA, START, and MDEQ continued monitoring the pH along Deer Creek and at the confluence with Lake Michigan.  pH readings in Deer Creek were consistently below 9.5 SU, except immediately downstream of the Tower Hill Road earthen berm.  The pH downstream of the Tower Hill Road earthen berm was 11.3 SU. Due to the elevated pH levels water containing a lower pH was pumped over the Tower Hill Road berm to aid in neutralization. USEPA, START, and MDEQ continued monitoring pH levels during pumping, pumping operations continued throughout the night.

By 7/24/2011, the soil berms protecting the catchbasins along Sawyer Road were all removed and Exit 12 on Eastbound I-94 and Sawyer Road were reopened to vehicular traffic.

On 7/24/2011 at approximately 0600 hours, the earthen berm at Sawyer Road failed.  The sand that was used to construct the berm was washed downstream.  Shortly after, the earthen berm at Tower Hill Road also failed and sand was washed downstream.  As a result, the water in Deer Creek became highly turbid.  USEPA, START, MDEQ, and Clean Harbors had planned to remove the berms mid-morning on 7/23/2011, but the berm failures prevented the need for labor removal. Following the berm failures MDEQ, USEPA, and START continued to monitor all downstream locations along Deer Creek.  As of 7/24/2011 at approximately 1130 hours, the pH readings at all monitoring locations along Deer Creek and at the confluence with Lake Michigan were below 9.0 SU.  MDEQ and USEPA determined that the water quality in Deer Creek has been restored.

Next steps

Deer Creek remains closed for the weekend.  County Health Department personnel will review data on 7/25/2011 to determine whether to reopen Deer Creek.

Clean Harbors will install silt fencing in Deer Creek to reduce the amount of suspended solids from the failed earthen berms that will enter Lake Michigan.