ARC 9206C

ARC 9206C

Rulemaking related to standards for the land application of sewage sludge

Notice of Intended Action for this rulemaking was published in the Iowa Administrative Bulletin on January 8, 2025, as ARC 8638C. A public hearing was held on the following date(s):

●January 28, 2025

●January 29, 2025

Twenty-nine people attended the first public hearing, and 19 people attended the second public hearing. No public comments pertinent to this rulemaking were provided at the hearings.One comment letter was received during the public comment period. No changes from the Notice have been made.

ITEM 1.Rescind 567—Chapter 67 and adopt the following new chapter in lieu thereof:

CHAPTER 67

STANDARDS FOR THE LAND APPLICATION OF SEWAGE SLUDGE

567—67.1(455B) Purpose and scope.

67.1(1) This chapter establishes standards for the land application of sewage sludge generated during the treatment of domestic sewage in a treatment works. This chapter applies to any generator, applicator, or both, and to sewage sludge applied to the land.

a.In areas that are not specifically addressed in this chapter or in 567—Chapter 68, but which are addressed in federal regulations for sewage sludge applied to land at 40 CFR Part 503, the federal regulations shall apply under this rule and are hereby adopted by reference under this chapter.

b.On a case-by-case basis, the department may impose requirements for the land application of sewage sludge in addition to or more stringent than the requirements in this chapter when necessary to protect public health and the environment from any adverse effect of a pollutant in the sewage sludge.

67.1(2) Sewage sludge generators shall ensure that the applicable requirements in this chapter are met when sewage sludge is land applied. If a sewage sludge generator determines that a person being supplied sewage sludge for land application is not complying with applicable requirements of the land application program, the generator shall work with the applicator to obtain compliance with the requirements. If subsequent compliance cannot be achieved, the generator shall not supply additional sewage sludge to the applicator.

67.1(3) Exclusions. In accordance with 40 CFR §503.6, this chapter does not establish requirements for the land application of sludge generated at an industrial facility, hazardous sewage sludge, sewage sludge with a polychlorinated biphenyl (PCB) concentration of 50 mg/kg or higher, incinerator ash, grit and screenings, or drinking water treatment sludge.

567—67.2(455B) Sampling and analysis.

67.2(1)  Any sewage sludge generator who intends to land apply sewage sludge shall:

a.Sample and analyze the waste to determine whether it meets the criteria for sewage sludge for Class I, II, or III; and

b.Analyze the waste to determine if any sources exist which may contribute significant quantities of potentially hazardous chemicals or other toxic substances. If any are found, the generator shall inform the department of their presence and shall analyze the waste for chemicals or substances in accordance with department guidelines.

67.2(2) Unless rules for specific programs under EPA or department authority provide otherwise, or unless other methods are approved by the department for a specific situation, samples taken and analyses made to document contamination under this chapter shall be conducted in accordance with the methods described in 567—67.9(455B).

567—67.3(455B) Land application plan. All sewage sludge generators wishing to land apply sewage sludge shall establish and maintain in writing a long-range plan for land application of sewage sludge. A copy of this plan shall be available at the facility for department inspection.

67.3(1) The long-range plan shall be:

a.Developed for a minimum period of five years;

b.Updated annually; and

c.Designed to ensure that land application can be conducted in accordance with the requirements of this chapter.

67.3(2) At a minimum, the long-term plan shall contain the following information in detail for the next calendar year and in general terms for the following four years:

a.An outline of the sewage sludge sampling schedule and procedures that will be followed;

b.A determination of the amount of land required for proper land application of the sewage sludge;

c.Identification of the land areas and appropriate land application methods that will be used;

d.For each land application area, the names of the landowners and the applicators, an identification of any legal arrangements related to the use of an area, and an outline of any restrictions or special conditions that exist regarding the use of an area for the land application of sewage sludge;

e.An overall land application schedule, including the areas being used, the time of year that land application will occur on each area, and the estimated application rate for each area; and

f.A determination of all of the following:

(1)The types and capacities of the required application equipment, including an outline of how the equipment will be made available and who will be responsible for conducting land application operations;

(2)The types and capacities of necessary sludge storage and handling structures;

(3)Whether any additional sludge storage or handling facilities are needed; and

(4)A timeline to construct or obtain any required additional sludge storage, handling, or application facilities or equipment.

567—67.4(455B) Special definitions.

67.4(1) Definitions in the Iowa Code. “Sewage sludge”is defined in Iowa Code section 455B.171(34). For the purposes of this chapter, the term includes materials derived from sewage sludge.

67.4(2) Definitions in the CFR. The following terms applicable to this chapter are defined in the referenced locations:

a.40 CFR §503.9: “dry weight basis,” “food crops,” and “person who prepares sewage sludge.”

b.40 CFR §503.11: “agronomic rate,” “annual whole sludge application rate,” “bulk sewage sludge,” and “cumulative pollutant loading rate.”

c.40 CFR §503.31: “land with a high potential for public exposure” and “land with a low potential for public exposure.”

67.4(3) The following definitions apply to this chapter:

“Applicator” or “sewage sludge applicator” means any person who applies sewage sludge to the land.

“Class I sewage sludge” means sewage sludge that meets the criteria under 67.6(1).

“Class II sewage sludge” means sewage sludge that meets the criteria under 67.7(1).

“Class III sewage sludge” means any sewage sludge that cannot meet either Class I sewage sludge criteria or Class II sewage sludge criteria.

“Generator” or “sewage sludge generator” means any person who generates sewage sludge, who derives a material from sewage sludge, or both.

567—67.5(455B) Permit requirements. Prior to any land application of sewage sludge, a permit must be obtained by the sewage sludge generator in accordance with the following requirements:

67.5(1) The permit for the land application of sewage sludge produced by a wastewater treatment facility that has been issued a construction permit from the department will be issued concurrently and as part of anoperation permit or NPDES permit. The issuance process and permit terms will be the same as those specified for NPDES permits in 567—Chapter 60.

67.5(2) The department will review, on a case-by-case basis, requests for a permit to land apply sewage sludge or any material derived from sewage sludge if the sewage sludge is produced outside of the state of Iowa or produced by a wastewater treatment plant that has not been issued a construction permit from the department.

567—67.6(455B) Land application requirements for Class I sewage sludge.

67.6(1) Class I criteria. Class I sewage sludge is sewage sludge that meets the pollutant concentrations in 67.6(1)“a,” the Class A pathogen reduction requirements in 67.6(1)“b,” and the vector attraction reduction (VAR) requirements in 67.6(1)“c.”

a.Class I pollutant concentrations. The concentration of each pollutant in the sewage sludge shall not exceed the concentration for the pollutant in Table 1.

TABLE 1—POLLUTANT CONCENTRATIONS

b.Class I pathogen requirements (Class A). The sewage sludge shall comply with 67.6(1)“b”(1) and “b”(2).

(1)The sewage sludge shall comply with one of the following monitoring processes. Compliance with pathogen density shall not be based on an average value. Each individual sample result shall meet the numerical pathogen standards.

1.The fecal coliform density in the sewage sludge shall be less than 1,000 Most Probable Number (MPN) per gram of total solids (dry weight basis), or

2.The Salmonella sp. bacteria density in the sewage sludge shall be less than three MPN per four grams of total solids (dry weight basis).

(2)The sewage sludge shall comply with one of the following analytical and treatment processes:

1.The sewage sludge temperature shall be maintained at a specific value for a period of time using one of the procedures detailed below.

●When the percent solids of the sewage sludge is 7 percent or higher, the sewage sludge temperature shall be 50 degrees Celsius (°C) or higher; the time period shall be 20 minutes or longer; and the temperature and time period shall be determined using Equation 1, except when small particles of sewage sludge are heated by either warmed gases or an immiscible liquid.

●When the percent solids of the sewage sludge is 7 percent or higher and small particles of sewage sludge are heated by either warmed gases or an immiscible liquid, the sewage sludge temperature shall be 50°C or higher; the time period shall be 15 seconds or longer; and the temperature and time period shall be determined using Equation 1.

●When the percent solids of the sewage sludge is less than 7 percent and the time period is at least 15 seconds, but less than 30 minutes, the temperature and time period shall be determined using Equation 1.

Equation 1: D = 131,700,000/10^0.1400t

Where D = time in days; t = temperature in °C

●When the percent solids of the sewage sludge is less than 7 percent, the sewage sludge temperature is 50°C or higher, and the time period is 30 minutes or longer, the temperature and time period shall be determined using Equation 2.

Equation 2: D = 50,070,000/10^0.1400t

Where D = time in days; t = temperature in °C

2.The sewage sludge shall meet all of the following requirements:

●The sludge pH shall be raised to above 12 and shall remain above 12 for 72 hours;

●The sludge temperature shall be above 52°C for 12 hours or longer during the period that the sludge pH is above 12; and

●At the end of the 72-hour period during which the sludge pH is above 12, the sludge shall be air dried to achieve a percent solids in the sludge greater than 50 percent.

3. Sewage sludge treated in other known processes shall be analyzed prior to pathogen treatment to determine whether it contains enteric viruses and viable helminth ova. After pathogen treatment, the density of enteric viruses in the sewage sludge shall be less than one plaque-forming unit per four grams of total solids (dry weight basis), and the density of viable helminth ova shall be less than one per four grams of total solids (dry weight basis). Once the process has been demonstrated to achieve the required pathogen reduction, the process must be operated under the same conditions that were used during the demonstration.

4.Sewage sludge treated by unknown processes or by processes operating at conditions less stringent than the operating conditions at which the sewage sludge could qualify as Class I under other alternatives shall be analyzed prior to pathogen treatment to determine whether the sewage sludge contains enteric viruses and viable helminth ova. The density of enteric viruses in the sewage sludge shall be less than one plaque-forming unit per four grams of total solids (dry weight basis), and the density of viable helminth ova shall be less than one per four grams of total solids (dry weight basis).

5.Sewage sludge shall be treated in one of the Processes to Further Reduce Pathogens (PFRP) described in 67.10(2).

6.Sewage sludge shall be treated in a process that is equivalent to a PFRP, as determined by the department.

c.Class I VAR requirements. The sewage sludge shall meet one of the following VAR requirements.

(1)The mass of volatile solids in the sewage sludge shall be reduced by a minimum of 38 percent.

(2)A portion of the previously anaerobically digested sewage sludge shall be digested anaerobically in the laboratory in a bench-scale unit for 40 additional days at a temperature between 30°C and 37°C. If, at the end of the 40 days, the volatile solids in the sludge at the beginning of that period are reduced by less than 17 percent, VAR is achieved.

(3)A portion of the previously aerobically digested sewage sludge that has 2 percent solids or less shall be digested aerobically in the laboratory in a bench-scale unit for 30 additional days at 20°C. If, at the end of the 30 days, the volatile solids in the sludge at the beginning of that period is reduced by less than 15 percent, VAR is achieved.

(4)The specific oxygen uptake rate (SOUR) for sewage sludge treated in an aerobic process shall be equal to or less than 1.5 milligrams (mg) of oxygen per hour per gram of total solids (dry weight basis) at a temperature of 20°C.

(5)Sewage sludge shall be treated in an aerobic process for 14 days or longer. During that time, the sewage sludge temperature shall be higher than 40°C and the average sewage sludge temperature shall be higher than 45°C.

(6)The sewage sludge pH shall be raised to 12 or higher, measured at 25°C, by alkali addition and, without the addition of more alkali, shall remain at 12 or higher for two hours and then at 11.5 or higher for an additional 22 hours.

(7)The percent solids of sewage sludge that does not contain unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 75 percent based on the moisture content and total solids prior to mixing with other materials.

(8)The percent solids of sewage sludge that contains unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 90 percent based on the moisture content and total solids prior to mixing with other materials.

(9)Sewage sludge shall be injected below the land surface, and no significant amount of the sludge shall be present on the land surface within one hour after injection.

(10)Sewage sludge applied to the land surface or placed on a surface disposal site shall be incorporated into the soil within six hours after application to or placement on the land.

67.6(2) Class I management practices. Class I sewage sludge may be land applied in conformance with the following rules:

a.Class I sewage sludge may be applied to a lawn or a home garden.

b.Class I sewage sludge shall be applied to the land at an annual whole sludge application rate that is equal to or less than the agronomic nitrogen uptake rate, unless otherwise specified by the department.

c.An information sheet shall be provided to a person who receives Class I sewage sludge that is sold or given away in a container for land application. The information sheet shall contain:

(1)The name and address of the sewage sludge generator;

(2)A statement that land application of the sewage sludge is prohibited except in accordance with the instructions on the information sheet; and

(3)The annual application rate for the sewage sludge.

67.6(3) Class I monitoring frequency.

a.The pollutants listed in Table 1, the pathogen density requirements, and the VAR requirements shall be monitored at the frequency stated in Table 2.

TABLE 2—MONITORING FREQUENCY

b.After the sewage sludge has been monitored for two years, the department may reduce the monitoring frequency, but in no case shall the monitoring frequency be less than once per year when sewage sludge is land applied.

67.6(4) Class I recordkeeping.

a.Both the generator and bulk sludge applicator of Class I sewage sludge shall develop the following information and retain it for five years:

(1) The concentration of each pollutant listed in Table 1 in the sewage sludge.

(2)The following certification statement: “I certify, under penalty of law, that the Class I sewage sludge requirements have been met. I am aware that there are significant penalties for false certification including the possibility of fine and imprisonment.”

(3)Descriptions of how the PFRP are met, how one of the VAR requirements is met, and how the management practices are met for each site.

b.Treatment works with a design flow rate of 1 million gallons per day (mgd) or greater and treatment works that serve 10,000 people or more shall submit the above information to EPA, using EPA’s NPDES eReporting Tool (NeT), by February 19 of each year for the previous calendar year.

567—67.7(455B) Land application requirements for Class II sewage sludge.

67.7(1) Class II criteria. Class II sewage sludge is sewage sludge that meets the pollutant concentrations in 67.7(1)“a,” the pathogen reduction requirements in 67.7(1)“b,” and the VAR requirements in 67.7(1)“c.”

a.Class II pollutant concentrations. The concentration of any pollutant in Class II sewage sludge shall not exceed the ceiling concentration for the pollutant in Table 3.

TABLE 3—CEILING CONCENTRATIONS

b.Class II pathogen reduction requirements. Class II sewage sludge shall meet one of the following three alternatives:

(1)Seven samples of the sewage sludge shall be collected at the time of disposal, and the geometric mean of the fecal coliform density shall be less than 2,000,000 MPN per gram of total solids (dry weight basis);

(2)Sewage sludge shall be treated in a PSRP described in 67.10(1); or

(3)Sewage sludge shall be treated in a process that is equivalent to a PSRP, as determined by the department.

c.Class II VAR requirements. The Class II VAR requirements are the same as those for Class I sewage sludge in 67.6(1)“c.”

67.7(2) Class II management practices. Class II sewage sludge may be land applied in conformance with the following:

a.Class II sewage sludge shall not be land applied:

(1)To a lawn or a home garden; or

(2)If it is likely to adversely affect a threatened or endangered species listed under section 4 of the Endangered Species Act, 16 U.S.C. 1533, effective December 27, 2022, or the species’ designated critical habitat.

b.Land application sites accepting Class II sewage sludge not meeting pollutant concentrations listed in Table 1 in 67.6(1) are subject to the cumulative pollutant loading rates listed in Table 4.

TABLE 4—CUMULATIVE POLLUTANT LOADING RATES

c.Class II sewage sludge shall be land applied:

(1)At an annual whole sludge application rate that is equal to or less than the agronomic nitrogen uptake rate, unless otherwise specified by the department; and

(2)Only to soils classified as acceptable throughout the top five feet of soil profile. Sewage sludge shall not be applied to soils classified as sand, loamy sand, or silt. The acceptability of a soil shall be determined using the USDA soil classifications.

d.Land application sites shall have soil pH maintained above 6.0, unless

(1)Crops prefer soils with lower pH conditions;

(2)The sludge meets the pollution concentrations contained in Table 1; or

(3)The site does not exceed calcium carbonate equivalent levels according to sound farm management practices.

If the soil pH is below 6.0, agricultural lime can be used to increase the pH to an acceptable level.

e.If sewage sludge is applied to land on which the soil loss exceeds the soil loss limits established by the county soil conservation district, the sludge shall be injected on the contour or shall be applied to the surface and mechanically incorporated into soil within 48 hours of application. Sewage sludge shall not be applied to ground having greater than 9 percent slope unless approved by the department.

f.Sewage sludge application on frozen or snow-covered ground should be avoided unless special precautions are taken, such as proven farm management practices to avoid runoff. If application on frozen or snow-covered ground is necessary, it shall be limited to land areas of less than 5 percent slope unless otherwise approved by the department.

g.In accordance with Table I in 567—paragraph 60.2(2)“c,” sewage sludge shall not be applied to land that is 35 feet or less from an open waterway. If sewage sludge is applied within 200 feet upgradient of a stream, lake, sinkhole, or tile line surface intake, it shall be injected or applied to the surface and mechanically incorporated into the soil within 48 hours of application unless otherwise approved by the department.

h.If sewage sludge is applied to land subject to flooding more frequently than once in ten years, the sludge shall be injected or shall be applied to the surface and mechanically incorporated into the soil within 48 hours. Information on which land is subject to flooding more frequently than once in ten years is available from the department.

i.Sewage sludge shall not be applied within 200 feet of an occupied residence or any well. Distances may be reduced to a minimum of 35 feet with the written agreement of both the well or residence owner and, in the case of residences, the occupant and an approved farm management plan that addresses soil erodibility, harvest residuals, buffer strips, and other sound farm management practices. The farm management plan shall be approved by the local soil conservation district in accordance with rules implementing Iowa Code sections 161A.42 through 161A.51.

j.After the land application of sewage sludge, all of the following restrictions shall apply:

(1)Food crops with harvested parts that touch the sewage sludge/soil mixture and that are totally above the land surface shall not be harvested for 14 months;

(2)Food crops, feed crops, and fiber crops shall not be harvested for 30 days;

(3)Animals shall not be allowed to graze on the land for 30 days;

(4)Turf grown on land where sewage sludge is applied shall not be harvested for one year after application when the harvested turf is placed on either land with a high potential for public exposure or a lawn, unless otherwise specified by the department;

(5)Public access to land with a high potential for public exposure shall be restricted for one year; and

(6) Public access to land with a low potential for public exposure shall be restricted for 30 days.

k.When required by the director, groundwater monitoring wells and surface monitoring points shall be installed and a monitoring program implemented. Samples must be analyzed by a laboratory that is equipped and competent to perform the required tests. The results shall be forwarded to the department on a stipulated schedule.

l.The sewage sludge generator shall provide information necessary to comply with the requirements of this chapter to the sewage sludge applicator and landowner.

m.The sewage sludge applicator shall provide written notice to the department prior to the initial application of sewage sludge. The notice shall include:

(1)The location, by legal description, of the land application site, and

(2)The name, address, telephone number, and NPDES permit number (if appropriate) of the landowner, sewage sludge generator, and applicator.

67.7(3) Class II monitoring frequency.

a.The pollutants listed in Table 3, the pathogen density requirements, and the VAR requirements shall be monitored at the frequency stated in Table 2.

b.After the Class II sewage sludge has been monitored for two years, the department may reduce the monitoring frequency, but in no case shall the monitoring frequency be less than once per year when sewage sludge is land applied.

67.7(4) Class II recordkeeping.

a.Both the generator and applicator of Class II sewage sludge shall develop all of the following information and retain it for five years:

(1)The concentration of each pollutant listed in Table 3 in the sewage sludge.

(2)The following certification statement: “I certify, under penalty of law, that the Class II sewage sludge requirements have been met. I am aware that there are significant penalties for false certification including the possibility of fine and imprisonment.”

(3)A description of how the PSRP and VAR requirements are met.

(4)A description of how the management practices for Class II sewage sludge are met for each site.

(5)The location and surface area of each site.

(6)The date and time of sewage sludge application at each site.

(7)If subjected to cumulative loading limits, the amount and cumulative amount of each pollutant listed in Table 4 of 67.7(2)“b” in the sewage sludge applied to each site.

(8)The amount of sewage sludge (i.e., metric tons) applied to each site.

b. Treatment works with a design flow rate of 1 mgd or greater and treatment works that serve 10,000 people or more shall submit the above information to EPA, using EPA’s NPDES eReporting Tool (NeT), by February 19 of each year for the previous calendar year. In addition, a supplemental sewage sludge report that includes the land application information listed in 67.7(4)“a”(6) through “a”(9) shall be submitted to the department by the same due date.

567—67.8(455B) Class III sewage sludge.

67.8(1) Class III sewage sludge is any sewage sludge that cannot meet either Class I or Class II sewage sludge criteria.

67.8(2) Class III sewage sludge shall not be utilized for beneficial use for land application as specified in the chapter.

67.8(3) Class III sewage sludge shall be disposed according to 40 CFR Part 503, Subpart C, “Surface Disposal,” or according to 40 CFR Part 503, Subpart E, “Incineration.”

567—67.9(455B) Sampling and analytical methods.

67.9(1) General. Representative samples of sewage sludge that are applied to the land shall be collected and analyzed. The methods and calculation procedures listed below shall be used to analyze samples and to calculate the percent of volatile solids reduction.

67.9(2) Enteric viruses. 40 CFR §503.8(b)(1) is adopted by reference.

67.9(3) Fecal coliform.

a.40 CFR §503.8(b)(2) is adopted by reference.

b.EPA Method 1680: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation using Lauryl Tryptose Broth (LBT) and EC Medium, EPA-821-R-14-009, September 2014.

c.EPA Method 1681: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation using A-1 medium, EPA-821-R-06-013, July 2006.

67.9(4) Helminth ova. 40 CFR §503.8(b)(3) is adopted by reference.

67.9(5) Inorganic pollutants.

a.Metals. 40 CFR §503.8(b)(4) is adopted by reference.

b.Nonmetals. For nonmetals not identified elsewhere in this chapter, methods listed in 567—paragraph 83.5(1)“c.”

67.9(6) Salmonella sp. bacteria.

a.40 CFR §503.8(b)(5) is adopted by reference.

b.EPA Method 1682: Salmonella in Sewage Sludge (Biosolids) by Modified Semisolid Rappaport-Vassiliadis (MSRV) Medium, EPA-821-R-06-14, July 2006.

67.9(7) Specific oxygen uptake rate. 40 CFR §503.8(b)(6) is adopted by reference.

67.9(8) Total, fixed, and volatile solids. 40 CFR §503.8(b)(7) is adopted by reference.

67.9(9) Percent volatile solids reduction calculation. “Environmental Regulations and Technology - Control of Pathogens and Vectors in Sewage Sludge,” EPA-625/R-92/013, July 2003.

567—67.10(455B) Pathogen treatment processes.

67.10(1) 40 CFR Part 503, Appendix B, section A, Processes to Significantly Reduce Pathogens (PSRP), is adopted by reference.

67.10(2) 40 CFR Part 503, Appendix B, section B, Processes to Further Reduce Pathogens (PFRP), is adopted by reference.

These rules are intended to implement Iowa Code section 455B.174.

[Filed 4/18/25, effective 6/18/25]

[Published 5/14/25]

EDITOR’S NOTE: For replacement pages for IAC, see IAC Supplement 5/14/25.