Section 604.230  Groundwater Quantity

a)         A community water supply must determine groundwater source adequacy by the amount of water produced by each well pumping within its calculated safe yield.

b)         Multiple Well Systems:  When multiple wells are used, the combined delivery must equal or exceed the maximum average daily demand under Section 604.105(a) with the largest producing well out of service.

c)         Single Well Systems:  No community water supply, the construction or modification of which commences after July 26, 2019, may rely only on a single well for its water source.  A community water supply, the construction of which commenced before and that is not modified after July 26, 2019, may rely on a single well for its water source, but must be placed on the critical review list under 35 Ill. Adm. Code 602.107.  For the purposes of this subsection, "modified" means when the fixed capital costs of the new components constructed within a 2-year period exceed 50% of the fixed capital cost of a comparable entirely new facility.

d)         The well location must be selected to minimize the impact on other wells and other water resources.