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FIVE-YEAR REVIEW REPORT

BURLINGTON NORTHERN BRAINERD/BAXTER

MINNESOTA

Prepared By: U.S. Environmental Protection Agency

Region V Chicago, Illinois

.r ^(i% /? at William E. Muno, Director Date Superfund Division

I. PURPOSE

Section 121© of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) requires that periodic (at least once every five years) reviews be conducted for sites where hazardous substances, pollutants or contaminants remain at the site above levels that allow for unlimited use or unrestricted exposure following the completion of all remedial actions for the site. The purpose of such a review is to determine the continued adequacy of the remedial actions implemented to provide protection of human health, welfare and the environment.

EPA has established three levels of review depending on the likelihood that the remedy remains protective. Level III would require the most in-depth review for sites where there is the greatest likelihood that the remedial actions implemented for sites are no longer protective. Level II is expected to be a less likely intensive review, followed by level I for sites where it is least likely the remedial actions are no longer protective. Burlington Northern is receiving a Level I review, because it is very unlikely the remedial actions for the site are no longer protective.

II. SITE HISTORY AND CONDITIONS

In 1982, EPA placed this site on its National Priorities List (NPL) of hazardous waste sites. The site is located partially in the City of Baxter and partially in the City of Brainerd, Minnesota. State Highway 371 is approximately 900 feet north of the site and the Mississippi River flows about 3,000 feet east of the site. Residential areas are located to the northeast and southeast of the site. Burlington Northern operated a railroad tie treating plant on the site between 1907 and 1985. The process consisted of pressure treatment using a heated creosote/coal tar or creosote/fuel oil mixture. Figure 1-1 is a map of the area around the site.

The primary groundwater contaminant sources were the shallow lagoons which were used to hold process wastewater. Between the opening of the plant and October 1982 wastewater was discharged to one of these lagoons. Burlington Northern began the site cleanup as a Superfund Remedial action pursuant to a CERCLA Section 106 Consent Order.

III. SUMMARY OF RESPONSE ACTIONS

Contaminants in the RCRA impoundment and the old (CERCLA) lagoon resulted from past discharges of creosote mixtures. The primary constituents of concern are Polynuclear Aromatic Hydrocarbons (PAH) compounds, heterocycles, and phenols. These constituents were present in the sludge in the impoundments and in soil beneath the impoundments.

All of the wastewater and liquid creosote were removed from the RCRA lagoon. The wastewater was pumped to rail-tank cars and transported to Burlington Northern's Northtown, Minnesota wastewater treatment plant for pretreatment and subsequent discharge to the sanitary sewer in 1982. The creosote was removed between 1982 and 1985 and reused or recycled.

In 1984 bench and pilot scale tests were conducted to evaluate the feasibility of using bioremediation for the contaminated soils and sludges from the lagoons. The study consisted of six pilot scale test plots and six bench scale reactors which varied in the initial creosote concentration. These tests were successful and a full scale treatment system was designed and constructed.

The treatment area consists of a 4 foot base of clean backfill, a 100 ml high density polyethylene liner and a leachate collection system. A lined staging area was prepared for the temporary storage of the sludge and contaminated soil. Between 1100 and 1500 cubic yards of soil were added to the treatment area each year. Treatment included:

1. Periodic monitoring of PAH, total phenols, benzene extractables and toxicity parameters.

2. Application of lime and nutrients as necessary to meet design criteria.

3. Periodic irrigation to maintain the treatment zone near field capacity.

4. Bi-weekly cultivation with a tractor mounted rototiller.

5. Maintenance of the leachate collection and run-off sumps.

A total of 14,000 cubic yards of contaminated soils were treated. About 7,000 cubic yards of soils were excavated from the former RCRA impoundment, 2,500 cubic yards were excavated from the former CERCLA impoundment, 3,500 cubic yards were excavated from other impacted areas and 1,000 cubic yards of sand, gravel and soil from the stockpile closure activities were placed in the treatment area. A summary of all materials and soils remediated are presented in Table l-l.

Performance standards for the soils treatment were based in part on significant reductions in total extractable hydrocarbons. A treatability study was completed that indicated that these standards could be achieved. Due to time limitations of the study, it was not discovered until several years of full-scale treatment had been completed that a "plateau" effect would limit the extent of biodegradation of the total extractable hydrocarbons. Based on full-scale monitoring data, it was observed that the rate of biodegradation of total extractable hydrocarbons confinued only to a concentration that was slightly above the target treatment goal. Thus the target treatment goal for total extractable hydrocarbons could not be met. The performance standards were also based on a qualitative toxicity standard measured by the Microtox TM analysis. Although significant reductions in toxicity were achieved, the treated soil was not rendered nontoxic as defined by the Microtox TM analysis. An evaluation of the monitoring data indicated that the residual creosote constituents were biostabilized desphe the higher than expected residual total extractable hydrocarbon levels and toxicity levels. A decision was made by USEPA and the MPCA to cap the treated material in place.

A cap was constructed over the treated material and this cap consisted of:

1. A 12-inch sand subgrade,

2. A 40-mil HDPE layer,

3. A 18-inch sandy clay soil,

4. and six inches of topsoil.

A groundwater monitoring plan was developed for the site. The receptors potentially affected by the migration of contaminants include surface water (the Mississippi River) and the glacial outwash aquifer which is used as a source if potable water. Concentration limits are based on the use of groundwater as a potable water supply. The following alternate concentration limits are established as action levels in the Consent Order:

1. 30 ug/1 for the sum of nine known or suspected carcinogenic PAH compounds identified in Table 2-1, List 1.

2. 300 ug/1 for the sum of the twenty two non-carcinogenic compounds identified in Table 2-1, List 2.

Meeting the concentration limits as the groundwater protection standard at the compliance points provides adequate protection of human health and the environment. Meeting the standard at the compliance points ensures that groundwater contamination will be well below these limits downgradient in the affected aquifer and at the Mississippi River due to the effects of sorption, dispersion, and degradation. The point of compliance is a vertical surface located at the hydraulically downgradient limit of the waste management unit that extends to the bottom of potentially affected groundwater underlying the waste management unit. The points of compliance are monitoring wells installed in the uppermost aquifer located immediately downgradient of the waste management area. The groundwater monitoring compliance period is equal to the closure and post-closure care period (30 years). If corrective action extends beyond the post-closure care period, then the compliance period extends until it is demonstrated that the groundwater protectiveness standard has not been exceeded for a period of five consecutive years.

Eleven monitoring wells are included in the monitoring network. All groundwater samples are analyzed for PAHs, heterocycles and total phenols. Three gradient control wells have been installed and are pumped at the rate of 50 gpm. Discharge is routed to a storm sewer in accordance with the NPDES permit. In the event that the discharge from the gradient control wells does not meet NPDES water quality standards, the system is equipped to route the flow through the Brainerd/Baxter municipal sewage treatment plant.

One year after completion of construction at the site the MPCA assumed primary responsibility for O & M. The Part B RCRA permit is currently being revised. This version will specify that

the air injection system replace the extraction wells as the gradient control system. This will replace a passive system with treatment only if permit levels are exceeded with an active air sparging system which significantly lowers contaminant levels in the groundwater. The extraction wells will remain in place and be maintained so that should contaminant levels rise due to deterioration in the air sparging system, they can be activated and remove the water from the aquifer for monitoring and then discharge to the river or divert it to the POTW if NPDES permit levels are exceeded.

IV. SCOPE AND NATURE OF THE FIVE-YEAR REVIEW

The EPA guidance for Five-year Reviews discusses three levels of review. This initial five-year review for the Burlington Northern Baxter/Brainerd site is a Level I Review because it is very unlikely that the selected remedy for the site is no longer protective.

The site was visited on November 13, 1997 by the EPA Remedial Project Manager (RPM). Also present at the site visit was an employee of Remediation Technologies, Inc., contractor for Burlington Northern. The purpose of this visit was to determine the current status of the site and adequacy of the site cleanup.

In addition to the site visit, the following documents, data and information were reviewed:

The EPA/MPCA Consent Order

Enforcement Decision Document (ROD Equivalent)

The Summary of Remedial Alternafive Selection

The Remedial Investigation and the Feasibility Study

The RCRA Part B permit Application, Two Volumes, June 1991

The RCRA Part B Permit

The NPDES Permit

The 1987-1994 Annual Soils Monitoring Reports

The 1987-1994 Annual Ground Water Monitoring Reports

The 1985-1986 Annual Monitoring Reports

IV. RESULTS OF THE FIVE-YEAR REVIEW

During the November 13, 1997 site visit, the RPM made the following observations relating to the current status of the site and the continued protectiveness of the Response Actions:

RETEC maintains an office at the site.

The fence around the site was intact and in good repair.

The monitoring wells at and around the site were functional and in good repair.

The air sparging system was functional and in good repair.

The cap was well vegetated with no significant bare spots.

The extraction well system was fully functional.

The June 4, 1986 Enforcement Decision Document (ROD equivalent) specifies that a gradient control system remain in place until the specified standards are met. Using the air sparging system in place of the groundwater extraction system will substitute an active system for a passive system thus increasing the effectiveness of the remedy.

In summary, the cleanup continues to protect human health, welfare, and the environment at this site. No specific or general deficiencies which need to be addressed were identified in this Five-Year Review.

EPA believes that the Five-Year Reviews continue to be necessary at this site since hazardous substances, pollutants or contaminants which are above levels allowed for unlimited use or unrestricted exposure remain at the site. Accordingly, we plan to conduct another Five-year Review in 2002.

Table 1-1 REMEDIAL ACTIVITIES SUMMARY FOR MISCELLANEOUS SITE/SOIL MATERIALS

FORMER BNRR TIE TREATING PLANT BRAINERD, MINNESOTA

SWMU Locatton

ProcfM Mid Storage Artaa

Concrete Building Foundations

Process Piping and Debris

Concrete Tank Foundations

Rebar Reinforcement

Impacted Soil

Drip Track Arts

Impacted Soil

BlacU Dock Area

Railroad Ties

Miscellaneous Debris

Impacted Soil

Temporary StockpUe Area

Residual Water and Leachate

Miscellaneous Debris

Impacted Soil

Geotextile Material

Leachate Collection Materials

HDPE Liner

Impacted Soil Beneath Sump

Leachate Collection Materials

Leachate Collection Sump

NA - not available

Activity

Demolition

Removal

Demolition

Removal

Excavation

Excavation

Removal

Removal

Excavation

Removal

Removal

Removal

Removal

Removal

Removal

Removal

Removal

Removal

Date

1989

1989

1992

1992

1989

1989

1991

1991

1991

1994

1994

1994

1994

1994

1994

1994

1994

1994

Material Description

Concrete

Steel

Concrete

Steel

Impacted soil

Impacted soil

Treated wood

Steel

Impacted soil

Liquid

Steel and plastic

Impacted Soil

Plastic

Sand and Gravel

Plastic

Impacted Soil

Cobbles

Plastic

Estimated Volume

1,533 CY

12 CY

170 CY

2 Tons

2,674 CY

238 CY

100 CY

NA

540 CY

NA

34,680 LB

1,250 CY

11,560 LB

1,050 CY

46 CY

40 CY

260 CY

320 LF

Treatment Method

Crushing

Off-site disposal

Crushing

Off-site recycling

On-site land treatment

On-site land treatment

Off-site recycling

Off-site recycling

On-site land U-eatment

Brainerd POTW

Off-site disposal

On-site land treatment

Off-site disposal

On-site land treatment

Dccontan\ination and On-site disposal

On-site land treatment

On-site disposal

On-site disposal

Location

LTU

FL Wayne, IN

LTU

Scrap yard

LTU

LTU

Braxton Industries Bovey, MN

Scrap yard

LTU

Brainerd, MN

Chemical Waste Management Model City, NY

LTU

Chemical Waste Management Model City. NY

LTU

LTU

LTU

LTU

LTU

'

Table 2-1

HAZARDOUS CONSTITUENTS

List 1 - Carcinogenic PAHs and Heterocycles

benzo(a)anthracene benzo(b)fluoranthene benzo(j )fluoranthene benzo(a)pyrene chrysene

ideno(l ,2,3-c,d)pyrene benzo(g,h,i)perylene dibenzo(a,h)antliracene quinoline

List 2 - Non-carcinogenic PAHs and Heterocycles

indene 2,3-dihydroindence naphthalene I -methylnaphthalene 2-methylnaphthalene biphenyl acenaphthylene acenapthene fluorene phenanthrene anthracene

fluoranthene pyrene benzo(h)fluoranthene benzo(e)pyrene perylene acridine carbazole 2,3-benzofuran benzo(b)thiophene dibenzothiophene indole