Ill. Admin. Code tit. 35 § 654.304

Current through Register Vol. 48, No. 49, December 6, 2024

Section 654.304 - Additional Required Samples

a) Check samples are required to verify an analysis showing contamination.

b) Check samples are required under the following conditions when the membrane filter technique is used:

1) four or more confirmed coliform colonies in a single sample;

2) excessive growth (confluent growth or too numerous to count) confirmed either positive or negative for coliform; or

3) one, two or three colonies of coliform in 25% or more of the samples analyzed.

c) Samples shall be collected at the same location at 24 hour intervals until the results of two consecutive samples indicate less than one coliform per 100 milliliters of sample.

d) Only one sample is required to check negative excessive growth.

e) Check samples shall not be used to calculate the monthly average.

f) Replacement samples are required when samples cannot be analyzed for any reason. This includes but is not limited to:

1) samples more than 30 hours old when received;

2) insufficient information on the sample sheet supplied by the sample collector (i.e. no date or time of collection recorded);

3) samples frozen;

4) sample bottles broken; or

5) residual chlorine present in sample.

g) Only one sample is required to replace a sample that has not been analyzed.

h) Results of replacement samples shall be included in the monthly average calculation.

Ill. Admin. Code tit. 35, § 654.304