567—133.4 (455B,455E) Response to contamination.
	 133.4(1) Prevention of further contamination. In all cases where an active source of contamination is identified, such as leaking tanks or current practices, which may be readily corrected, the source shall be removed, repaired or otherwise contained, or the contaminating practices ceased, immediately upon discovery of the source. In addition, readily accessible contaminants, for example concentrated contaminants spilled on the ground or accessible through a recovery well or system, shall be promptly removed to avoid or minimize further contamination in the groundwater.
	 133.4(2) Aggravated risk. Where the contamination presents an aggravated risk, the preventative, investigatory and remedial measures provided in subrules 133.4(1) and 133.4(3) shall be expedited to remove such risk. In addition, the following actions shall be taken by the responsible parties, if necessary, to protect the public health or environment:
	  a.   	 Providing alternate water supplies.
	  b.   	 Installing security fencing or other measures to limit access.
	  c.   	 Extraordinary measures to control the source of release.
	  d.   	 Removal of hazardous substances to an approved site for storage, treatment or disposal.
	  e.   	 Placing physical barriers to deter the spread of the release.
	  f.   	 Recommending to appropriate authorities the evacuation of threatened individuals.
	  g.   	 Using other materials to restrain the spread of the contaminant or to mitigate its effects.
	  h.   	 Executing damage control or salvage operations.
	 133.4(3) Significant risk. In cases of significant risk, the following investigatory and remedial measures shall be implemented:
	  a.   	 Investigation. The responsible party shall determine the extent and levels of contamination through a site assessment conducted under the supervision of a registered professional engineer, an expert in the field of hydrogeology, or other qualified person. A site assessment plan shall be submitted to the department within 45 days of notice by the department, unless a shorter time is required or a longer time is authorized by the department. The plan shall be approved by the department prior to initiation of the assessment, unless otherwise approved by the department. The site assessment shall be conducted within a reasonable time and a remedial action plan shall be submitted to the department, within the time directed or approved by the department. The department may require further investigation by the responsible person in order to adequately assess the extent of contamination, and may require the remedial action plan to be supplemented if necessary.
	  b.   	 Required cleanup actions.
	 (1) 	 Groundwater. The goal of groundwater cleanup is use of best available technology and best management practices as long as it is reasonable and practical to remove all contaminants, and in any event until water contamination remains below the action level for any contaminant, and the department determines that the contamination is not likely to increase and no longer presents a significant risk. Where site conditions and available technology are such that attainment of these goals would be impractical, the department may establish an alternative cleanup level or levels, including such other conditions as will adequately protect the public health, safety, environment, and quality of life.
	 (2) 	 Other. Where significant amounts of contaminants are documented as being present in the soils or other environment, such that groundwater contamination is occurring or is likely, active cleanup of the contaminated soils or other environment shall be implemented to the extent reasonable and necessary to prevent or minimize release to the groundwater; passive cleanup may be allowed in extraordinary circumstances.
	 133.4(4) Other. Where significant risk is not currently present, the responsible person may be required to monitor the groundwater and implement reasonable management or other preventative measures to minimize further contamination.