Munoz Borrow Pits
The Munoz Borrow Pits site is located 0.1 mile south of U.S. 83, on the east side of Texas 1016 in Mission. In the late 1950s, the property owner accepted several dump truck loads of soil contaminated with pesticides and arsenic. The soil was placed in piles on the property to be used as fill. A 1982 citizen's complaint to the EPA triggered an inspection; an investigation of possible pesticide contamination, and a search for the original owner of the contaminated soil. November 5, 1982, the Texas Department of Water Resources field office inspected the site and collected samples of the soil for analysis. In 1985 or 1986, the piles, estimated to be 2,500 cubic feet of soil, were spread across an area of 100 feet by 400 feet on the southern portion of the Munoz property to prepare part of the property for a bull ring.
Superfund Actions Taken to Date
- July 25, 1986, a legal notice was published in the Texas Register (11 TexReg 3421-3422) proposing the Munoz Borrow Pits site to the state Superfund registry and announcing a public meeting to receive citizen comments would be held at Coastal Bend Council of Governments Conference Room in Corpus Christi on August 26, 1986, and a second public meeting would be held at the Stephen F. Austin Building in Austin on August 26, 1986.
- August 26, 1986, a public meeting was held in Corpus Christi to receive public comments on the proposal of the site to the state Superfund registry and to identify any additional potentially responsible parties.
- January 16, 1987, Munoz Borrow Pits became 1 of 10 sites on the first Texas Superfund registry (12 TexReg 205), and the Texas Water Commission requested the Hidalgo County clerk to record the Munoz property, including all land, structures, appurtenances and other improvements, as a state Superfund site
- November 25, 1988, the Texas Water Commission published a legal notice in the Texas Register (13 TexReg 5939) inviting independent third parties to participate voluntarily in remedial action at the site. Third parties could then seek cost recovery under the Solid Waste Disposal Act , Article 4477-7, §11(b) from those liable parties not participating in the voluntary cleanup. The state disclaimed any liability for reimbursement of the costs of the work.
- January 5, 1990, Texas Water Commission (predecessor agency to TNRCC) issued a work order to determine the nature and extent of contamination (remedial investigation/feasibility study) after the owner granted access to the property.
- September 1, 1993, effective date of the creation of the Texas Natural Resource Conservation Commission from the joining of the Texas Water Commission and the Texas Air Control Board and a portion of the Texas Department of Health.
- February 23, 1996, TNRCC issued a work order to the engineer to prepare plans and specifications for a removal action.
- October 16, 1996, TNRCC approved an immediate removal action to excavate the pesticide-contaminated soil and dispose of it off-site.
- June 10, 1997, a legal notice was published in the Texas Register (22 TexReg 5708-5709) and the local newspaper announcing a public meeting would be held July 29, 1997, at the city hall in Mission, to present to the community the best choice among cleanup remedies and to receive citizen comments to be considered in the final recommended remedy.
- July 10, 1997, the contractor completed the removal of the contaminated soil.
- July 29, 1997, TNRCC held a public meeting at the City Hall in Mission to receive public comment on the removal action. Additional samples were taken at the site to verify that the soil remediation goals had been achieved.
- July 3, 1998, a legal notice was published in the Texas Register (23 TexReg 7137) and the Mission Progress Times proposing to delete the site from the state Superfund registry in accordance with 30 TAC §335.344(c), and inviting public comment on the determination that soil on the site no longer presented an imminent and substantial endangerment to public health and safety or the environment.
- August 7, 1998, TNRCC issued an administrative order, directing the potentially responsible party to perform or fund the groundwater monitoring for natural attenuation at a rate of twice a year for the first three years and then annually until the attenuation had cleaned the groundwater to established groundwater cleanup levels.
- August 17, 1998, effective date of the administrative order establishing rules, responsibilities and enforcement options for monitoring the groundwater for natural attenuation.
- September 11, 1998, a legal notice was published in the Texas Register, (23 TexReg 9499-9500) officially deleting the Munoz Borrow Pits from the state Superfund registry in accordance with 30 TAC §335.344(c). No challenges or comments were received to the determination that the soil on the site no longer presented an imminent and substantial endangerment to public health and safety or the environment. The TNRCC is monitoring natural attenuation of contaminated groundwater at the site which is now considered appropriate for residential use.
- September 22, 1998, a notice of a lien against the property was recorded in Hidalgo County, seeking to recover the state's portion of costs associated with site activities to date.
- June 23, 2000, TNRCC received the monitoring report from the site operations and maintenance contractor on the natural attenuation of contaminated groundwater. This marked the end of the first year O&M groundwater monitoring at the site.
- July 1, 2001–August 2002, TNRCC continued ongoing operation and maintenance activities, which currently consist of semi-annual groundwater monitoring to ensure that the contaminants are attenuating the concentration through natural processes.
- September 1, 2002, effective date of the name change from Texas Natural Resource Conservation Commission (TNRCC) to Texas Commission on Environmental Quality (TCEQ).
- June 16, 2003, a notice was filed in Hildalgo County real property records that the lien had been removed.
- September 2002–August 2003, TCEQ continued ongoing operation and maintenance activities consisting of semi-annual monitoring to ensure the natural attenuation process of the groundwater continues as the remedy for the site.
- December 2003, two damaged groundwater monitoring wells were re-drilled. A third well was plugged and abandoned. The remaining groundwater wells were sampled to continue the operations and maintenance.
- January 2004, TCEQ received and accepted the semiannual groundwater monitoring report.
- March 2004, TCEQ issued a work order to the contractor to update the list of chemicals that need to be sampled during the operations and maintenance phase, and to survey the replacement monitor wells that were installed in December 2003.
- June 2004, TCEQ issued a work order to survey the new wells.
- August 2004, TCEQ received a survey map of the locations of the new monitor wells. The analytical results of the semiannual groundwater monitoring was also received and accepted.
- September 2004, TCEQ issued a work order for continued groundwater monitoring into the year 2005.
- February 2005, the contractor performed the semi-annual groundwater sampling event at the site.
- March 24, 2005, the data usability summary report was approved for the February 2005 groundwater sampling event.
- September 2005, the contractor conducted quarterly groundwater sampling.
- January 2006, the contractor conducted quarterly groundwater sampling.
- May 2006, the contractor conducted quarterly groundwater sampling.
- June 2006, a work order was issued for plugging the groundwater monitoring wells at the site.
- August 2006, all monitoring wells were plugged. No further remedial action is planned.