Illinois Administrative Code › Title 35 - ENVIRONMENTAL PROTECTION › Part 611 - PRIMARY DRINKING WATER STANDARDS › Subpart W - INITIAL DISTRIBUTION SYSTEM EVALUATIONS › Section 611.925 - Subpart Y Compliance Monitoring Location Recommendations

Current through Register Vol. 48, No. 28, July 12, 2024
a) A supplier's IDSE report must include its
				recommendations and justification for where and during what months it will
				conduct TTHM and HAA5 monitoring for Subpart Y. The supplier must base its
				recommendations on the criteria set forth in subsections (b) through
				(e).
b) The supplier must select
				the number of monitoring locations specified in the applicable of subsections
				(b)(1) through (b)(13), subject to the limitations of subsections (b)(14) and
				(b)(15). The supplier will use these recommended locations as Subpart Y routine
				compliance monitoring locations, unless the Agency requires different or
				additional locations. The supplier should distribute locations throughout the
				distribution system to the extent possible.
1) A Subpart B system supplier that serves
				fewer than 500 persons must annually collect samples from two monitoring
				locations: one sample from the highest TTHM location and one sample from the
				highest HAA5 location.
2) A Subpart
				B system supplier that serves 500 to 3,300 persons must quarterly collect
				samples from two monitoring locations: one sample from the highest TTHM
				location and one sample from the highest HAA5 location.
3) A Subpart B system supplier that serves
				3,301 to 9,999 persons must quarterly collect samples from two monitoring
				locations: one sample from the highest TTHM location and one sample from the
				highest HAA5 location.
4) A Subpart
				B system supplier that serves 10,000 to 49,999 persons must quarterly collect
				samples from four monitoring locations: two samples from the highest TTHM
				locations, one sample from the highest HAA5 location, and one sample from an
				existing Subpart I compliance location.
5) A Subpart B system supplier that serves
				50,000 to 249,999 persons must quarterly collect samples from eight monitoring
				locations: three samples from the highest TTHM location, three samples from the
				highest HAA5 locations, and two samples from existing Subpart I compliance
				locations.
6) A Subpart B system
				supplier that serves 250,000 to 999,999 persons must quarterly collect samples
				from 12 monitoring locations: five samples from the highest TTHM location, four
				samples from the highest HAA5 locations, and three samples from existing
				Subpart I compliance locations.
7)
				A Subpart B system supplier that serves 1,000,000 to 4,999,999 persons must
				quarterly collect samples from 16 monitoring locations: six samples from the
				highest TTHM location, six samples from the highest HAA5 locations, and four
				samples from existing Subpart I compliance locations.
8) A Subpart B system supplier that serves
				more than 5,000,000 persons must quarterly collect samples from 20 monitoring
				locations: eight samples from the highest TTHM location, seven samples from the
				highest HAA5 locations, and five samples from existing Subpart I compliance
				locations.
9) A groundwater system
				supplier that serves fewer than 500 persons must annually collect samples from
				two monitoring locations: one sample from the highest TTHM location and one
				sample from the highest HAA5 location.
10) A groundwater system supplier that serves
				500 to 9,999 persons must annually collect samples from two monitoring
				locations: one sample from the highest TTHM location and one sample from the
				highest HAA5 location.
11) A
				groundwater system supplier that serves 10,000 to 99,999 persons must quarterly
				collect samples from four monitoring locations: two samples from the highest
				TTHM locations, one sample from the highest HAA5 location, and one sample from
				an existing Subpart I compliance location.
12) A groundwater system supplier that serves
				100,000 to 499,999 persons must quarterly collect samples from six monitoring
				locations: three samples from the highest TTHM locations, two samples from the
				highest HAA5 locations, and one sample from an existing Subpart I compliance
				location.
13) A groundwater system
				supplier that serves more than 500,000 persons must quarterly collect samples
				from eight monitoring locations: three samples from the highest TTHM locations,
				three samples from the highest HAA5 locations, and two samples from existing
				Subpart I compliance locations.
14)
				The supplier must monitor during the month of highest DBP
				concentrations.
15) A supplier on
				quarterly monitoring must take dual sample sets every 90 days at each
				monitoring location, except for a Subpart B system supplier that serves 500 to
				3,300 persons. A groundwater system supplier that serves 500 to 9,999 persons
				which is on annual monitoring must take dual sample sets at each monitoring
				location. Any other supplier that is on annual monitoring or which is a Subpart
				B system supplier that serves 500 to 3,300 persons is required to take
				individual TTHM and HAA5 samples (instead of a dual sample set) at the
				locations with the highest TTHM and HAA5 concentrations, respectively. For a
				supplier that serves fewer than 500 people, only one location with a dual
				sample set per monitoring period is needed if the highest TTHM and HAA5
				concentrations occur at the same location and month.