PUBLIC HEALTH ASSESSMENT
BRIO REFINING, INC.
DIXIE OIL PROCESSOR, INC.
The Brio Refining, Inc. (Brio) and Dixie Oil Processors (DOP) NPL Sites are located
approximately 20 miles southeast of Houston, Texas. The shallow groundwaters of both sites are
heavily contaminated with volatile organic chemicals (VOCs). The documents reviewed did not
indicate that there was any known use of contaminated groundwater from the shallow aquifer
(Numerous Sand Channel Zone [NSCZ] and Fifty-Foot Sand zones) near the site for human
consumption. There are approximately 28 water wells (both potable and non-potable) within a
one-mile radius of the sites which were completed in the deeper aquifers (>400 feet deep).
deeper aquifers are separated from the upper aquifers by a 100 foot thick clay aquitard. The
deeper aquifers are not known to be contaminated at this time. No surface drinking water intakes
were identified n the surrounding area. Former on-site pits are heavily contaminated with VOCs,
polyaromatic hydrocarbons (PAHs), metals, and semi-volatile compounds. On-site remedial or
construction activities could expose workers to air, soil, and groundwater contamination, and
could lead to the off-site migration of contaminants if
appropriate precautions are not
implemented. Human contact with sediment from Mud Gully south of Dixie Farm Road would
not be expected to pose a Significant Health Risk. Analyses of air ad soil samples form Southbend
Subdivision did not reveal significant contamination with site-related chemicals. Based on the
available information, the Brio/DOP Sites are of public health concern, but currently pose no
significant risk to public
health under the assumptions that contaminated groundwater is not used
for human consumption and the site conditions and migration pathways remain unchanged.
A. SITE DESCRIPTION
The Brio/DOP sites are located in Harris County approximately 20 miles Southeast of Houston, Texas (see Appendix, Figure 1). The sites are about 1.5 miles southwest of Interstate 45 at the Ellington Field Exit. About one to two miles further south is the community of Friendswood. The Brio/DOP sites are located north and south of Dixie Farm Road. For simplicity, the sites will be referred to as Brio north, Brio south, DOP north and DOP south. The Brio orth and DOP north sites are separated by a flood control ditch called Mud Gully, which discharges to Clear Creek. Brio is bordered on the northwest (NW) by Southbend Subdivision and to the northeast (NE) by Beamer Road. DOP is bordered on the NW by open fields and an athletic field to the southwest (SW). Other areas surrounding both sites are open lands used for oil and gas production. The Brio and DOP sites are 58.1 and 26.6 acres respectively. Both sites north of Dixie Farm Road were used for storage purposes (impoundments and pits). The areas south of Dixie Farm Road were mainly used for processing activities. There are on-site water supply wells at both brio/DOP sites. These wells were intended for potable and non-potable use and were completed in the aquifer at a depth of approximately 475 feet.
Approximately 23 unlined storage pits were constructed and closed on the Brio site during the period 1957 to 1982.
From 1957 to 1969, the major industrial operations included regeneration of cooper catalysts, recovery of petrochemicals from styrene tars and recovery of chemicals from vinyl chloride still bottoms. Reclamation of petrochemicals from various chemical feedstocks also occurred at Brio. Because of a lack of processing capacity, styrene tars were stored in large impoundments.
Spent caustics were stored in tanks during 1969 to 1971. Hydrogen sulfide was blended with spent caustic to produce cresylic acid, sodium sulfide and sodium crystallite.
During the time period 1975 to 1978, styrene tar, diesel fuel that did not meet specifications, ethylbenzene, phenol bottom, cutter stock, caustic, crude oil, blend oil, polyethylbenzene bottoms, and crankcase oil were utilized as feedstock.
Styrene tars were stored in open pits on the site. Several pits were closed between 1957 to 1977.
The recovery plant was converted to a crude oil topping unit for jet fuel production in 1978. Different fuels were produced by distillation of crude oil. No cracking or reforming of feedstocks took place.
Six unlined impoundments were used by DOP north for cooper catalyst recovery and hydrocarbon washing operations from 1969 to 1978. The impoundments were used to store the wastewater prior to cooper recovery and to treat the wastewater prior to discharge. Wastewater from the hydrocarbon washing operation was discharged into one of the impoundments. The impoundments were closed during the above period.
DOP south began operations in 1978. The operations were similar to DOP north. The site was used to regenerate copper chloride catalyst and hydrocarbon washing to produce ethylbenzene, toluene, aromatic solvents, styrene pitch, and for oil recovery. Feedstocks were residues from local chemical plants and refineries (phenolic tank bottom tars and glycol cutter stock).These were blended and distilled to produce various petroleum products, including fuel oil, creosote extender, and a molybdenum catalyst. Presently, both DOP north and DOP south use some of the storage tanks for an intermediate storage operation.
B. SITE VISIT
A site visit was made on January 25 to 27, 1988, with ATSDR Headquarters and Regional personnel, the EPA Remedial Project Manager, and members of the Brio Task Force. The site was fenced and appeared to be well secured. Site security personnel were present.
The area surrounding the site appears to have experienced a moderate population growth. Residences, businesses, a hospital, and a school were located within about one-half mile of the site. Much land is still used for cattle grazing and oil production.
The site terrain is level. Mud Bully Creek, which passes through the site, did not appear to be visibly polluted. The Brio/DOP north soils contained many small black objects that appeared to be tar residues. All process pits were backfilled and leveled to the surrounding terrain. Evidence of apparent plant toxicity was found at the northwestern area between DOP and Brio north near Mud Gully. A 10-20 foot by 100 foot long strip of land along the northern and western edges of Brio north contained a black granulated soil and was devoid of plant life. Analyses of soil samples from the bare areas reportedly did not detect significant concentrations of priority pollutants; therefore the cause of the phytotoxicity is unknown. Surface runoff from this area enters Mud Gully.