R311-211-7. Significance Level

(a) Where contamination is identified that is below applicable MCLs, water classification standards, or air quality standards or where applicable standards do not exist for either the parameter in question or the environmental media in which the contamination is found, the cleanup standard shall be established using R311-211-3 and will be set between background and the observed level of contamination. Should it be determined that the observed level of contamination will be allowed to remain, this becomes the significance level.

(b) At any time, should continued monitoring identify contamination above the significance level, the criteria of R311-211-3 will be reapplied in connection with R311-211-4 to re-evaluate the need for corrective action and determine an appropriate cleanup standard.