Section 604.235  Groundwater Quality 

a)         Each community water supply using groundwater must collect and analyze one sample per well per month for total coliform bacteria.  The analysis must be performed by a certified laboratory.

1)         If a routine sample result is total coliform-positive, the community water supply must collect and analyze another sample within 24 hours after being notified of the positive result.  The analysis must be performed by a certified laboratory.

2)         Results that show the presence of coliform and have been confirmed by a sample taken under subsection (a)(1) must be reported to the Agency within 24 hours after being notified of the positive result of the sample taken under subsection (a)(1).

b)         The Agency must require multiple barrier treatment to achieve at least 99.99 percent (4-log) removal or inactivation of viruses for all groundwater sources subject to bacteriological contamination.

c)         When maintenance or equipment replacement on a well occurs that does not require a construction or operating permit under 35 Ill. Adm. Code 602, one sample from the well must be submitted to a certified laboratory for analysis for total coliform bacteria.

1)         If the sample result is satisfactory, the well may be placed into service.

2)         If the sample result is unsatisfactory, the well may not be placed into service until samples collected from the well on two consecutive days and tested by a certified laboratory have satisfactory results.

d)         A source water assessment under Section 604.315 must be completed considering factors, both natural and manmade, that may affect water quality in the groundwater.