Michigan Administrative Code › Department - Environmental Quality › Drinking Water And Municipal Assistance Division › Supplying Water to the Public › Part 6 - STATE DRINKING WATER STANDARDS AND ANALYTICAL › Section R. 325.10611h - Enhanced treatment for Cryptosporidium; microbial toolbox options for meeting Cryptosporidium treatment requirements

Current through Vol. 24-12, July 15, 2024
Rule 611h.
(1)
				  Subpart H supplies that are subject to R 325.10611d receive the treatment
				  credits listed in the table in subrule (2) of this rule by meeting the
				  conditions for microbial toolbox options described in R 325.10611i to R
				  325.10611m. Subpart H supplies apply these treatment credits to meet the
				  treatment requirements in R 325.10611f.
(2) The following table summarizes options in
				  the microbial toolbox:
Table 1 Microbial Toolbox Summary Table: Options, Treatment
					 Credits, and Criteria
Toolbox Option
Cryptosporidium treatment credit with design and
								implementation criteria
Source Protection and Management Toolbox
								Options
(a) Watershed control program
0.5-log credit for department-approved program
								comprising required elements, annual program status report to department, and
								regular watershed survey. Specific criteria are in R 325.10611i (1).
(b) Alternative source/intake management
No prescribed credit. Subpart H supplies may conduct
								simultaneous monitoring for treatment bin classification at alternative intake
								locations or under alternative intake management strategies. Specific criteria
								are in R 325.10611i (2).
Pre Filtration Toolbox Options
(c) Presedimentation basin with coagulation
0.5-log credit during a month that presedimentation
								basins achieve a monthly mean reduction of 0.5-log or greater in turbidity or
								alternative department-approved performance criteria. To be eligible, basins
								shall be operated continuously with coagulant addition and all plant flow shall
								pass through basins. Specific criteria are in R 325.10611j (1).
(d) Two-stage lime softening
0.5-log credit for 2-stage softening where chemical
								addition and hardness precipitation occur in both stages. All plant flow shall
								pass through both stages. Single-stage softening is credited as equivalent to
								conventional treatment. Specific criteria are in R 325.10611j (2).
(e) Bank filtration
0.5-log credit for 25-foot setback; 1.0- log credit
								for 50-foot setback; aquifer shall be unconsolidated sand containing not less
								than 10% fines; average turbidity in wells shall be less than 1 NTU. Subpart H
								supplies using wells followed by filtration when conducting source water
								monitoring shall sample the well to determine bin classification and are not
								eligible for additional credit. Specific criteria are in R 325.10611j (3).
Treatment Performance Toolbox Options
(f) Combined filter performance
0.5-log credit for combined filter effluent
								turbidity less than or equal to 0.15 NTU in not less than 95% of measurements
								each month. Specific criteria are in R 325.10611k (1).
(g) Individual filter performance
0.5-log credit (in addition to 0.5-log combined
								filter performance credit) if individual filter effluent turbidity is less than
								or equal to 0.15 NTU in not less than 95% of samples each month in each filter
								and is never greater than 0.3 NTU in 2 consecutive measurements in a filter.
								Specific criteria are in R 325.10611k (2).
(h) Demonstration of performance
Credit awarded to unit process or treatment train
								based on a demonstration to the department with a department-approved protocol.
								Specific criteria are in R 325.10611k (3).
Additional Filtration Toolbox Options
(i) Bag or cartridge filters (individual filters).
Up to 2-log credit based on the removal efficiency
								demonstrated during challenge testing with a 1.0-log factor of safety. Specific
								criteria are in R 325.10611l (1).
(j) Bag or cartridge filters (in series).
Up to 2.5-log credit based on the removal efficiency
								demonstrated during challenge testing with a 0.5-log factor of safety. Specific
								criteria are in R 325.10611l (1).
(k) Membrane filtration
Log credit equivalent to removal efficiency
								demonstrated in challenge test for device if supported by direct integrity
								testing. Specific criteria are in R 325.10611l (2).
(l) Second stage filtration
0.5-log credit for second separate granular media
								filtration stage if treatment train includes coagulation before first filter.
								Specific criteria are in R 325.10611l (3).
(m) Slow sand filters
2.5-log credit as a secondary filtration step;
								3.0-log credit as a primary filtration process. No prior chlorination for
								either option. Specific criteria are in R 325.10611l (4).
Inactivation Toolbox Options
(n) Chlorine dioxide
Log credit based on measured CT in relation to CT
								table. Specific criteria in R 325.10611m (2).
(o) Ozone
Log credit based on measured CT in relation to CT
								table. Specific criteria in R 325.10611m (2).
(p) UV
Log credit based on validated UV dose in relation to
								UV dose table; reactor validation testing required to establish UV dose and
								associated operating conditions. Specific criteria in R 325.10611m (4).