SECTION 252:515-9-54. Approved statistical methods

  One of the following statistical methods shall be used to evaluate groundwater monitoring data for each chemical parameter and hazardous constituent:

(1)   a parametric analysis of variance (ANOVA) followed by multiple comparisons procedures to identify statistically significant evidence of contamination. The method must include estimation and testing of the contrasts between each compliance well's mean and the background mean levels for each constituent;

(2)   an ANOVA based on ranks followed by multiple comparisons procedures to identify statistically significant evidence of contamination. The method must include estimation and testing of the contrasts between each compliance well's median and the background median levels for each constituent;

(3)   a tolerance or prediction interval procedure in which an interval for each constituent is established from the distribution of the background data, and the level of each constituent in each compliance well is compared to the upper tolerance or prediction limit;

(4)   a control chart approach that gives control limits for each constituent; or

(5)   another statistical test method may be approved by the DEQ if it meets the performance standards of OAC 252:515-9-53.

[Source: Added at 20 Ok Reg 1151, eff 6-1-03]