Texas Administrative Code › Title 30 - ENVIRONMENTAL QUALITY › Part 1 - TEXAS COMMISSION ON ENVIRONMENTAL QUALITY › Chapter 335 - INDUSTRIAL SOLID WASTE AND MUNICIPAL HAZARDOUS WASTE › Subchapter K - HAZARDOUS SUBSTANCE FACILITIES ASSESSMENT AND REMEDIATION › Section 335.348 - General Requirements for Remedial Investigations

Current through Reg. 49, No. 28; July 12, 2024
(a) Unless otherwise directed by the
				  commission, a remedial investigation as approved by the executive director
				  shall be completed before the executive director's selection of the remedial
				  action, except for removals and preliminary site investigations in accordance
				  with §
										335.346
				  of this title (relating to Removals and Preliminary Site
				  Investigations).
(b) A similar
				  study may be approved by the executive director as an appropriate alternative
				  to the performance of a full remedial investigation when necessary to avoid
				  delay, to make more effective use of resources or when such similar study is
				  sufficient to adequately characterize a site.
(c) The contents of the remedial
				  investigation as approved by the executive director, will depend on the
				  particular circumstances of each specific facility. Under any remedial
				  investigation, however, sufficient information must be collected and evaluated
				  to allow the executive director to select an appropriate remedial
				  action.
(d) A remedial
				  investigation may include the following, as appropriate to a particular
				  facility, for the purpose of allowing the executive director to select an
				  appropriate remedial action:
(1)
				  investigations of surface water and sediments necessary to characterize
				  hydrologic features such as surface drainage patterns, areas of erosion and
				  sediment deposition, surface waters, floodplains, and actual or potential
				  hazardous substance migration routes within these areas. Properties of surface
				  and subsurface sediments, which would influence the type and rate of hazardous
				  substance migration or affect the ability to implement alternative remedial
				  actions, shall be characterized;
(2) investigations to adequately characterize
				  the nature and extent of hazardous substances in the soils encompassing the
				  facility. Properties associated with the soils, which would influence the type
				  and rate of hazardous substance migration or affect the ability to implement
				  alternative remedial actions, shall be characterized;
(3) investigations of hydrogeology and
				  geology to adequately characterize the nature and extent of hazardous
				  substances in the groundwater and the features which affect the fate and
				  transport of those hazardous substances. This should include, but is not
				  limited to, the physical properties and distribution of bedrock and
				  unconsolidated materials, groundwater flow rate and gradient for contaminated
				  and potentially contaminated aquifers, groundwater divides, areas of
				  groundwater recharge and discharge, and location of public and private
				  groundwater wells;
(4) information
				  regarding local climatological characteristics which are likely to affect the
				  hazardous substance migration such as: rainfall patterns; frequency of storm
				  events; temperature variations; prevailing wind direction; and wind
				  velocity;
(5) an ecological risk
				  assessment;
(6) descriptions of the
				  location, quantity, horizontal and vertical extent, concentrations and sources
				  of hazardous substances. Information on the physical and chemical
				  characteristics and the toxicological effects of hazardous substances shall be
				  provided, if available; and
(7) a
				  feasibility study.