/Significant deficiencies. Systems must address significant deficiencies identified during sanitary surveys as described in 43.1(7).
Table 1: Source Water Monitoring Schedule
System | First round of monitoring | Second round of monitoring |
Serves at least 100,000 people | October 2006 | April 2015 |
Serves 50,000-99,999 people | April 2007 | October 2015 |
Serves 10,000-49,999 people | April 2008 | October 2016 |
Serves fewer than 10,000 people and only conducts E. coli monitoring | October 2008 | October 2017 |
Serves fewer than 10,000 people and conducts Cryptosporidium monitoring | April 2010 | April 2019 |
* Physically composite the source samples into a single sample for analysis. Systems may composite the sample from each source into one sample prior to analysis. The volume of the sample from each source must be weighted according to the proportion of the source in the total plant flow at the time the sample is collected.
* Analyze the samples separately and mathematically composite the results. Systems may analyze samples from each source separately and calculate a weighted average of the analytical results for each sampling date. The weighted average must be calculated by multiplying the analytical result for each source by the fraction that source contributed to the total plant flow at the time the sample was collected and then summing the weighted analytical results.
* "Method 1623:Cryptosporidium andGiardia in Water by Filtration/IMS/FA," 2005, US EPA, EPA-815-R-05-002. Available at www.nemi.gov ;
* "Method 1622:Cryptosporidium in Water by Filtration/IMS/FA," 2005, US EPA, EPA-815-R-05-001. Available at www.nemi.gov ; and
* "Method 1623.1:Cryptosporidium andGiardia in Water by Filtration/Immunomagnetic Separation/Immunofiuorescence Assay Microscopy," 2012, EPA-816-R-12-001. Available at www.nepis.epa.gov .
* PWSID.
* Facility ID.
* Sample collection date.
* Sample type (i.e., field or matrix spike).
* Sample volume filtered (L), to the nearest 0.25 L.
* Whether 100 percent of the filtered volume was examined by the laboratory.
* Number of oocysts counted.
* For matrix spike samples: sample volume spiked and estimated number of oocysts spiked.
* For samples in which less than 10 L is filtered or less than 100 percent of the sample volume is examined: the number of filters used and the packed pellet volume.
* For samples in which less than 100 percent of sample volume is examined: the volume of resuspended concentrate and the volume of this resuspension processed through immunomagnetic separation.
Table 2:E. coli Analytical Methods
Method | EPA | Standard Methods | Other |
Most probable number with multiple tube or multiple well1.2 | 9223 B11 | 991.154 Colilert3.5Colilert-183,5,6 | |
Membrane filtration, single step1.7.8 | 16039 | m-ColiBlue2410 | |
Membrane filtration, two step | 9222D/9222G12 |
1Tests must be conducted to provide organism enumeration (i.e., density). Select the appropriate configuration of tubes/filtrations and dilutions/volumes to account for the quality, consistency, and anticipated organism density in the water sample.
2Samples shall be enumerated by the multiple-tube or multiple-well procedure. Using multiple-tube procedures, employ an appropriate tube and dilution configuration of the sample as needed and report the Most Probable Number (MPN). Samples tested with Colilert® may be enumerated with the multiple-well procedures, Quanti-Tray®, Quanti-Tray® 2000, and the MPN calculated from the table provided by the manufacturer.
3These tests are collectively known as defined enzyme substrate tests, where, for example, a substrate is used to detect the enzyme beta-glucouronidase produced byE. coli.
4Association of Official Analytical Chemists, International. "Official Methods of Analysis of AOAC International, 16th Ed., Volume 1, Chapter 17, 1995. AOAC, 481 N. Frederick Ave., Suite 500, Gaithersburg, MD 20877-2417.
5Descriptions of the Colilert®, Colilert-18®, Quanti-Tray®, and Quanti-Tray® 2000 may be obtained from IDEXX Laboratories, Inc., 1 IDEXX Drive, Westbrook, ME 04092.
6Colilert-18® is an optimized formulation of the Colilert® for the determination of total coliforms andE. coli that provides results within 18 hours of incubation at 35 degrees C rather than the 24 hours required for the Colilert® test.
7The filter must be a 0.45 micron membrane filter or a membrane filter with another pore size certified by the manufacturer to fully retain organisms to be cultivated and to be free of extractables which could interfere with organism growth.
8When the membrane filter method has been used previously to test waters with high turbidity or large numbers of noncoliform bacteria, a parallel test should be conducted with a multiple-tube technique to demonstrate applicability and comparability of results.
9Method 1603:Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified Membrane-ThermotolerantEscherichia coli Agar (modified mTEC), USEPA, July 2006." US EPA, Office of Water, Washington, DC, EPA 821-R-06-011. Available at www.nepis.epa.gov .
10A description of the m-ColiBlue24® test, Total Coliforms andE. coli, is available from Hach Company, 100 Dayton Ave., Ames, IA 50010.
11Standard Methods forthe Analysis of Water and Wastewater, 18th (1992), 19th (1995), and 20th (1998) editions, American Public Health Association. Available from APHA, 800 I Street, NW, Washington, DC 20001-3710.
12Standard Methods for the Examination of Water and Wastewater, 20th edition (1998). Available from APHA, 800 I Street, NW, Washington, DC 20001-3710.
* PWSID.
* Facility ID.
* Sample collection date.
* Analytical method number.
* Method type.
* Source type (flowing stream or river; lake or reservoir; or influenced groundwater).
* Number ofE. coli per 100 mL.
* Turbidity in NTU.
* Determine one inactivation ratio before or at the first customer during peak hourly flow.
* Determine successive sequential inactivation ratios between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Calculate the total inactivation ratio by determining the inactivation ratio for each sequence (CTcalc/CT99.9) and adding the values together.
Table 3: Bin Classification Table
System Type | Cryptosporidium Concentration, in oocysts/L | Bin Classification |
Systems required to monitor for Cryptosporidium under 43.11(3) b (1) or 43.11(3)"b"(2)"3" | Fewer than 0.075 oocysts/L | Binl |
Between 0.075 and fewer than 1.0 oocysts/L | Bin 2 | |
Between 1.0 and fewer than 3.0 oocysts/L | Bin 3 | |
3.0 oocysts/L or greater | Bin 4 | |
Systems serving fewer than 10,000 and not required to monitor for Cryptosporidium, pursuant to 43.11 (3) "b "(2)"1" | Not applicable | Binl |
Table 4: AdditionalCryptosporidium Treatment Requirements
Bin Classification | Treatment Used by the System for Compliance with 43.5, 43.9, and 43.10 | |||
Conventional filtration (including softening) | Direct filtration | Slow sand or diatomaceous earth filtration | Alternative filtration technologies | |
Binl | No additional treatment | No additional treatment | No additional treatment | No additional treatment |
Bin 2 | 1-log treatment | 1.5-log treatment | 1-log treatment | At least 4.0-log1 |
Bin 3 | 2-log treatment | 2.5-log treatment | 2-log treatment | Atleast5.0-log1 |
Bin 4 | 2.5-log treatment | 3-log treatment | 2.5-log treatment | At least 5.5-log1 |
1The totalCryptosporidium removal and inactivation must be at least this value, as determined by the department.
Table 5:Cryptosporidium Treatment Compliance Dates
Schedule | Population Served by System | Compliance Date for Cryptosporidium treatment requirements1 |
1 | At least 100,000 people | April 1,2012 |
2 | From 50,000 to 99,999 people | October 1, 2012 |
3 | From 10,000 to 49,999 people | October 1, 2013 |
4 | Fewer than 10,000 people | October 1, 2014 |
1The department may allow up to an additional two years for compliance with the treatment requirement if the system must make capital improvements.
Table 6: Microbial Toolbox Summary Table: Options, Treatment Credits, and Criteria
Toolbox Option | Specific Criteria Rule | Cryptosporidium treatment credit with design and implementation criteria |
Source Protection and Management Toolbox Options | ||
Watershed control program | 43.11(9) | 0.5-log credit for department-approved program comprising required elements, annual program status report to department, and regular watershed survey. |
Alternative source/intake management | 43.11(9)"b" | No prescribed credit. Systems may conduct simultaneous monitoring for treatment bin classification at alternative intake locations or under alternative intake management strategies. |
Prefiltration Toolbox Options | ||
Presedimentation basin with coagulation | 43.11(10)"a" | 0.5-log credit during any 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 must be operated continuously with coagulant addition and all plant flow must pass through the basins. |
Two-stage lime softening | 43.11(10) "b" | 0.5-log credit for two-stage softening where chemical addition and hardness precipitation occur in both stages. All plant flow must pass through both stages. Single-stage softening is credited as equivalent to conventional treatment. |
Bank filtration | 43.11(10)"c" | 0.5-log credit for 25-foot setback; 1.0-log credit for 50-foot setback; aquifer must be unconsolidated sand containing at least 10 percent fines; average turbidity in wells must be less than 1 NTU. A system using a well followed by filtration when conducting source water monitoring must sample the well to determine bin classification and is not eligible for additional credit. |
Treatment Performance Toolbox Options | ||
Combined filter performance | 43.11(11)"a" | 0.5-log credit for combined filter effluent turbidity less than or equal to 0.15 NTU in at least 95 percent of measurements each month. |
Individual filter performance | 43.11(11)"b" | 0.5-log credit (in addition to the 0.5-log combined filter performance credit) if individual filter effluent turbidity is less than or equal to 0.15 NTU in at least 95 percent of samples each month in each filter and is never greater than 0.3 NTU in two consecutive measurements in any filter. |
Demonstration of performance | 43.11(11)"c" | Credit awarded to unit process or treatment train based on a demonstration to the department with a department-approved protocol. |
Additional Filtration Toolbox Options | ||
Bag or cartridge filters (individual filters) | 43.11(12)"a" | Up to 2-log credit based on the removal efficiency demonstrated during challenge testing with a 1.0-log factor of safety. |
Bag or cartridge filters (in series) | 43.11(12)"a" | Up to 2.5-log credit based on the removal efficiency demonstrated during challenge testing with a 0.5-log factor of safety. |
Membrane filtration | 43.11(12) "b" | Log credit equivalent to removal efficiency demonstrated in challenge test for device if supported by direct integrity testing. |
Second-stage filtration | 43.11(12)"c" | 0.5-log credit for second separate granular media filtration stage if treatment train includes coagulation prior to first filter. |
Slow sand filtration | 43.11(12)"d" | 2.5-log credit as a secondary filtration step; 3.0-log credit as a primary filtration process. No prior chlorination for either option. |
Inactivation Toolbox Options | ||
Chlorine dioxide | 43.11(13) | Log credit based on measured CT in relation to CT table. |
Ozone | 43.11(13) | Log credit based on measured CT in relation to CT table. |
Ultraviolet light (UV) | 43.11(13) | 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. |
* The watershed sanitary survey must meet the following criteria: encompass the region identified in the department-approved watershed control plan as the area of influence; assess the implementation of actions to reduce source waterCryptosporidium levels; and identify any significant new sources ofCryptosporidium.
* If the department determines that significant changes may have occurred in the watershed since the previous watershed sanitary survey, systems must undergo another watershed sanitary survey by the date specified by the department, which may be earlier than the regular schedule of a three- or five-year frequency.
Maximum Feed Water Concentration = 10,000 x Filtrate Detection Limit
LRV = LOG10(Cf) - LOG10(Cp)
Where:
LRV = log removal value demonstrated during challenge test;
Cf = the feed concentration measured during the challenge test; and
Cp= the filtrate concentration measured during the challenge test.
Equivalent units must be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, the term Cpmust be set equal to the detection limit.
Maximum Feed Water Concentration = 3,160,000 x Filtrate Detection Limit
LRV = LOG10(Cf) - LOG10(Cp)
Where:
LRV = log removal value demonstrated during challenge test;
Cf = the feed concentration measured during the challenge test; and
Cp= the filtrate concentration measured during the challenge test.
Equivalent units must be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, the term Cpmust be set equal to the detection limit for the purpose of calculating the LRV. An LRV must be calculated for each membrane module evaluated during the challenge test.
* For direct integrity tests using applied pressure or vacuum, the direct integrity test sensitivity must be calculated according to the following equation: LRVDIT= LOG10[QP/(VCF x Qbreach)]
Where:
LRVDIT=the sensitivity of the direct integrity test;
Qp = total design filtrate flow from the membrane unit;
Qbreach= flow of water from an integrity breach associated with the smallest integrity test response that can be reliably measured; and
VCF = volumetric concentration factor, which is the ratio of the suspended solids concentration on the high-pressure side of the membrane relative to that in the feed water.
* For direct integrity tests using a particulate or molecular marker, the direct integrity test sensitivity must be calculated according to the following equation:
LRVDIT= LOG10(cf) - LOG10(Cp)
Where:
LRVDIT=the sensitivity of the direct integrity test;
Cf = the typical feed concentration of the marker used in the test; and
Cp= the filtrate concentration of the marker from an integral membrane unit.
Table 7: Microbial Toolbox Reporting Requirements
Toolbox Option | Systems must submit this information | Information must be submitted on this schedule |
1. Watershed control program | Notice of intention to develop a new or continue an existing watershed control program | No later than two years before the applicable treatment compliance date in 43.11(7) |
Watershed control plan | No later than one year before the applicable treatment compliance date in 43.11(7) | |
Annual watershed control program status report | Every 12 months, beginning one year after the applicable treatment compliance date in 43.11(7) | |
Watershed sanitary survey report | -For community water systems, every three years beginning three years after the applicable treatment compliance date in 43.11(7) -For noncommunity water systems, every five years beginning five years after the applicable treatment compliance date in 43.11(7) | |
2. Alternative source/intake management | Verification that system has relocated the intake or adopted the intake withdrawal procedure reflected in monitoring results | No later than the applicable treatment compliance date in 43.11(7) |
3. Presedimentation | Monthly verification of the following: -Continuous basin operation -Treatment of 100 percent of the flow -Continuous addition of a coagulant -At least 0.5-log mean reduction of influent turbidity or compliance with alternative department-approved performance criteria | Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) |
4. Two-stage lime softening | Monthly verification of the following: -Chemical addition and hardness precipitation occurred in two separate and sequential softening stages prior to filtration -Both stages treated 100 percent of plant flow | Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) |
5. Bank filtration | Initial demonstration of the following: -Unconsolidated, predominantly sandy aquifer -Setback distance of at least 25 feet for 0.5-log credit or 50 feet for 1.0-log credit | No later than the applicable treatment compliance date in 43.11(7) |
If monthly average of daily maximum turbidity is greater than 1 NTU, then system must report result and submit an assessment of the cause. | Report within 30 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) | |
6. Combined filter performance | Monthly verification of combined filter effluent (CFE) turbidity levels less than or equal to 0.15 NTU in at least 95 percent of the 4-hour CFE measurements taken each month | Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) |
7. Individual filter performance | Monthly verification of the following: -Individual filter effluent (IFE) turbidity levels less than or equal to 0.15 NTU in at least 95 percent of samples each month in each filter -No individual filter effluent turbidity levels greater than 0.3 NTU in two consecutive readings 15 minutes apart | Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) |
8. Demonstration of performance | Results from testing following a department-approved protocol | No later than the applicable treatment compliance date in 43.11(7) |
As required by the department, monthly verification of operation within conditions of department approval for demonstration of performance credit | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) | |
9. Bag filters and cartridge filters | Demonstration that the following criteria are met: -Process meets the definition of bag or cartridge filtration -Removal efficiency established through challenge testing that meets criteria in this subpart | No later than the applicable treatment compliance date in 43.11(7) |
Monthly verification that 100 percent of plant flow was filtered | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) | |
10. Membrane filtration | Results of verification testing demonstrating the following: -Removal efficiency established through challenge testing that meets criteria -Integrity test method and parameters, including resolution, sensitivity, test frequency, control limits, and associated baseline | No later than the applicable treatment compliance date in 43.11(7) |
Monthly report summarizing the following: -All direct integrity tests above the control limit - If applicable, any turbidity or alternative department-approved indirect integrity monitoring results triggering direct integrity testing and the corrective action that was taken | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) | |
11. Second-stage filtration | Monthly verification that 100 percent of flow was filtered through both stages and that first stage was preceded by coagulation step | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7) |
12 Slow sand filtration as a secondary filter | Monthly verification that both a slow sand filter and a preceding separate stage of filtration treated 100 percent of the flow from surface or influenced groundwater sources | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43 11(7) |
13 Chlorine dioxide | Summary of CT values for each day as described in 43 11(13) | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43 11(7) |
14 Ozone | Summary of CT values for each day as described in 43 11(13) | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43 11(7) |
15 Ultraviolet light (UV) | Validation test results demonstrating operating conditions that achieve required UV dose | No later than the applicable treatment compliance date in 43 11(7) |
Monthly report summarizing the percentage of water entering the distribution system that was not treated by UV reactors operating within validated conditions for the required dose as specified in 43 11(13)"f" | Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43 11(7) |
Iowa Admin. Code r. 567-43.11