Section 611.1359  Analytical Methods

The supplier must conduct analyses for lead, copper, pH, conductivity, calcium, alkalinity, orthophosphate, silica, and temperature using the methods in Section 611.611(a).

a)         Only a certified laboratory in one of the categories in Section 611.490(a) may conduct analyses for lead and copper to demonstrate that a supplier complies with this Subpart AG.  To obtain certification for conducting analyses for lead and copper, a laboratory must fulfill specific conditions:

1)         The laboratory must analyze lead- and copper-containing performance evaluation samples provided by USEPA or the Agency;

2)         The laboratory must achieve certain quantitative acceptance limits:

A)        For lead:  ±30 percent of the actual amount in the performance evaluation sample when the actual amount is greater than or equal to 0.005 mg/L (the PQL for lead is 0.005 mg/L);

B)        For copper:  ±10 percent of the actual amount in the performance evaluation sample when the actual amount is greater than or equal to 0.050 mg/L (the PQL for copper is 0.050 mg/L);

3)         The laboratory must achieve the method detection limit (MDL) for lead of 0.001 mg/L using the procedures in 35 Ill. Adm. Code 186 and appendix B to 40 CFR 136: "Definition and Procedure for the Determination of the Method Detection Limit—Revision 1.11", incorporated by reference in Section 611.102(c).  The laboratory needs only accomplish this if the laboratory will process source water composite samples under Section 611.1358(a)(1)(D); and

4)         The laboratory must have current certification to perform analyses under the specifications this subsection (a)(1) describes.

BOARD NOTE:  This subsection (a) corresponds with Section 611.359(a) and derives from 40 CFR 141.89(a) and (a)(1) (2020).

b)         The Agency must issue a SEP allowing a supplier to use previously collected monitoring data under this Subpart AG if the supplier collected and analyzed the data complying with this Subpart AG.

BOARD NOTE:  This subsection (b) corresponds with Section 611.359(b) and derives from 40 CFR 141.89(a)(2) (2020).

c)         Reporting Lead and Copper Levels

1)         The supplier must report all lead and copper levels greater than or equal to the lead and copper PQL (Pb (0.005 mg/L and Cu (0.050 mg/L) as measured.

2)         The supplier must report all lead and copper levels less than the PQL but greater than the MDL (0.005 mg/L > Pb > MDL and 0.050 mg/L > Cu > MDL) either as measured or as one-half the PQL in subsection (a) (i.e., 0.0025 mg/L for lead or 0.025 mg/L for copper).

3)         The supplier must report all lead and copper levels below the lead and copper MDL (MDL > Pb) as zero.

BOARD NOTE:  This subsection (c) corresponds with Section 611.359(c) and derives from 40 CFR 141.89(a)(3) and (a)(4) (2020).

(Source:  Added at 47 Ill. Reg. 16486, effective November 2, 2023)