Biosolids Applied to Land Advancing Standards and Practices (2002) / Chapter Skim
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2 Biosolids Management
2 Biosolids Management
Pages 31-105
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From page 31... ...
. Sewage sludge is defined as We solid, semi-solid, or liquid residue generated during the treatment of domestic sewage in a treatment works, and biosolids are defined in this report as sewage sludge that has been treated to meet standards for land application under Part 503 of the CWA or any other equivalent land-application standards.
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From page 32... ...
. Recognizing that sewage-sludge production will continue to increase and that sewage sludge possesses many potential beneficial properties for agricultural production, federal and state agencies have long advocated the recycling of it as biosolids through land application (EPA 1981, 1984, 1991~.
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From page 34... ...
34 en En i,, a)
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From page 35... ...
The requirements apply to each of the three major methods of ultimate disposition of sewage sludge or biosolids: recycling and public distribution, burial in a municipal solid-waste landfill or a surface disposal site, or incineration. Enforceable standards are established for all three options, but this report focuses only on land application and public distribution.
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From page 36... ...
Many states consider the land application of biosolids to be a point-source discharge to groundwater and regulate this practice under the permit program. Individual homes that are connected to a municipal system, use a septic system, or do not
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From page 37... ...
EPA conducted an aggregate public-health risk assessment that estimated the risk from land application of biosolids in the absence of any regulation. That aggregate assessment found that the risk would be less than one cancer case per year and that approximately 1,000 persons would exceed a threshold lead concentration and 500 would experience some lead-related health effects.
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From page 38... ...
. Final Regulations There are three major categories of requirements establishing biosolids quality and site-management criteria for land application.
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From page 39... ...
Next, a back calculation was used to determine a maximum concentration in the biosolids that would not allow the maximum cumulative loading rate to be attained. The pollutant concentration limits are intended to define biosolids that can be land applied without requiring the applier to track cumulative pollutant loadings.
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From page 40... ...
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From page 41... ...
Biosolids having the least further restrictions on land application are those meeting the Class A pathogen requirements, the vector control requirements, and the high-quality pollutant concentration limits for metals. If all these requirements are met, the biosolids can be used with no more restrictions than any other fertilizer or soil-amendment product.
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From page 42... ...
In addition, after the 72-h period, the sewage sludge must be air dried to at least 50% TS. Alternative 3 Prior Test for Enteric Virus and Viable Helminth Ova: The sewage sludge must be analyzed for the presence of enteric viruses
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From page 43... ...
If the sewage sludge is analyzed before pathogen-reduction processing and found to have densities of enteric virus greater than or equal to 1 PFU/4 g of TS or viable helrninth ova of more than 1 per 4 g of TS and is tested again after processing and found to have densities of enteric virus of less than 1 PFU/4 g of TS and viable heltninth ova less than 1 per 4 g of TS, the sewage sludge is considered Class A biosolids when the treatment process is operated under the same conditions that successfully reduced enteric virus and helminth ova. Alternative 4 Post-Test for Enteric Virus and Viable Helminth Ova Process: If the sewage sludge is not analyzed before pathogen-reduction processing for enteric viruses and viable helminth ova, the sewage-sludge density of enteric viruses must be less than 1 PFU/4 g of TS, and the density of viable helminth ova must be less than 1 per 4 g of TS at the time the sew
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From page 44... ...
To obtain a Class A biosolid rating, the process must reduce Salmonella species or fecal coliforms to below Class A criteria and must operate under the specified conditions used in its application demonstration to the EPA Pathogen Equivalency Committee (see below)
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From page 45... ...
(This process cannot be satisf~ed during the winter in most of the northern United States without additional measures being taken to maintain adequate temperatures.) Anaerobic Digestion: Treat the sewage sludge in the absence of air for a specific mean cell residence time at a specific temperature.
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From page 46... ...
This can be a potential issue with the short-term options since they are reversible. It should also be noted that treatment should be complete prior to land application so that further reaction does not occur in the field, which may result in the release of odorants.
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From page 47... ...
Drying Without Primary Solids: 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% based on the moisture content and total solids prior to mixing with other materials. Drying with Primary Solids: 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% based on the moisture content and total solids prior to mixing with other materials.
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From page 48... ...
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From page 49... ...
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From page 50... ...
Rule Modifications Two lawsuits were brought shortly after the 1993 rule promulgation, involving three chemical pollutants (chromium, selenium, and molybdenum) , that caused modifications to the land application section of 40 CFR 503.
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From page 51... ...
After promulgation of the Part 503 regulations in 1993, EPA decided that the land application of biosolids was a low risk to public health and therefore the biosolids oversight program was given a low priority in its annual budget. That decision was based on the aggregate risk assessment, which showed negligible adverse effects even without regulation.
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From page 52... ...
However, there has been no documented scientific evidence to substantiate those claims. There have also been several allegations of animal deaths caused by land application of biosolids (e.g., cases in Colorado and Georgian.
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From page 53... ...
Given the ongoing need for OW and OECA to set priorities amongits many programs concerning public health and environmentalprotection, they maintain that their limited resources are better allocated elsewhere. · In late 2000, EPA requested and sponsored an NRC study to review information on the land application of biosolids and reexamine the risk-assessment methods used in developing the Part 503 regulations in light of recent research Endings and advances in risk assessment to determine whether the standards were still adequately protective of human health.
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From page 54... ...
Public perception of land application of biosolids has a significant impact on the implementation of the program. EPA Resources The committee notes that it has long been recognized by those within EPA working in the biosolids held and state agencies required to implement the biosolids program that EPA disinvestment in the program has caused an inability to adequately ensure that the regulations are followed.
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From page 55... ...
Some municipalities (orlocalunits of government) in the United States have adopted local ordinances pertaining to land application.
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From page 56... ...
AOxa LAsb DE~pc APES PAEIe PCB! 500 2,600 100 50 6 08 Dioxins Proposed Limit Values (ng1E/kg DM)
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From page 57... ...
standards and those of other countries, it is important that the differences be acknowledged and the bases for those differences used to inform future risk assessments. This section provides an overview of how different European countries have approached the management of biosolids for land application.
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From page 58... ...
Greece, Luxembourg, Ireland, Italy, Portugal, and Spain have set limit values similar to those in the directive; values for Poland, an accession country, are also lower than the European Union standards. The United Kingdom legislation differs by not providing any limit values for heavy metals in biosolids but rather specifying the maximum annual average loads of heavy metals to soil that are similar to the directive (Table 2-6~.
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From page 59... ...
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From page 62... ...
In all member states, regulations on the use of biosolids specify limit values for heavy metals in soil that are similar in most cases to the requirements set in the directive (Table 2-9~. Some countries have defined limit values for several categories of soil pH or limit the maximum load of heavy metals to agricultural lands on a 10-year basis.
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From page 63... ...
· Public opinion in Germany has recently swung in favor of agricultural land application, mainly because this practice is considered economically viable and the potential risks are sufficiently reduced by the existing legislation, which is now being reviewed. · In Austria, France, and the Walloon region of Belgium, national (or regional)
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From page 64... ...
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From page 65... ...
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From page 66... ...
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From page 67... ...
67 Cal A .
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From page 68... ...
Moreover, within the context of uncertainties concerning the potential impacts on human health and the environment of the various disposal and recycling options, additional research is needed to increase conf~dence in the use of biosolids in agriculture. Some strategies suggested by the recent European Union biosolidsmanagement assessment for reducing constraints and encouraging recycling of biosolids include the following (European Communities 20019: · Certify the treatment process involved, the quality of biosolids, and .
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From page 69... ...
When European Union biosolids-management practices are compared with those of the U.S., it is apparent that European and U.S. contaminant limits apply largely to heavy metals and are based on (1)
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From page 70... ...
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From page 72... ...
The Sewage Sludge Directive requires member states to apply maximum limit values for certain heavy metals in the biosolids and in the soil to which it is applied; to pretreat sewage sludge; and to restrict its use, including the frequency and quantity of application, on certain soils. These regulations establish conditions relating to pretreatment, nutrient needs, quality of soil, protection of surface waters and groundwaters, and compliance with concentration limits of heavy metals in soil.
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From page 73... ...
The maximum annual quantities of heavy metals indicated in Table 2-6 that may be added to the soil because of use of biosolids should not be exceeded. These limit values are intended to be reviewed every 6 years with a view toward achieving mediumand long-term concentrations for pollution prevention.
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From page 74... ...
Although animal manures are generally land applied and untreated and contain pathogens of concern, only biosolids are addressed in this report. Concerns for pathogen control in Classes A and B biosolids were expressed.
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From page 75... ...
Source: Adapted from European Union 2000b. further disinfection of land-applied Class B biosolids is related to management and treatment by natural attenuation.
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From page 76... ...
Abbreviations: DM, dry matter; TE, 2,3,7,8-tetrachloro-~dioxin toxicity equivalents. Source: Adapted from European Union 2000b.
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From page 77... ...
As a result of the workshop deliberations, the consensus opinion of the participating virologists was that Class-B-treatment processes should yield the reductions summarized in Table 2-16 if the processes are properly conducted and maintained and the site's climate, geology, and soil characteristics enable natural attenuation. Regarding the assessment of helminth eggs and protozoan oocysts, the efficacy of existing Class B disinfection processes for inactivating parasites
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From page 78... ...
The workshop participants expressed interest in using Closiridi~m perfringens as an indicator organism when noncharged biocides are the major agent for inactivation and for anaerobic digestion, lagoon storage, comporting, and alkaline stabilization. The existing Part 503 regulation states that the Class A disinfected biosolids are far less a concern as a result of Discard egg controls along with the temperature factors.
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From page 79... ...
Class A disinfection processes generally eliminate these competing microorganisms, requiring retesting of Class A biosolids if used in bulk quantities more than 3 weeks or so after production. Bioaerosol generation is a concern with the processes of aerobic digestion, anaerobic digestion, comporting, alkaline stabilization, and combinations.
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From page 80... ...
· Field verification of efficacy of Class A and Class B treatment processes (including data to directly relate process controls to initial and final pathogen and indicator densities)
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From page 81... ...
503. Determination of several such treatment technologies expected within a few years are vermicomposting, microwave technology, infrared irradiation technology, alkaline stabilization, anaerobic digestion, and aerobic digestion.
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From page 82... ...
IMPLEMENTATION AND END-USE PRACTICES Overview There are three major alternatives for final disposition of sewage sludge: (1) recycling as biosolids to agricultural land as a fertilizer or soil amendment or selling or giving away to the public for use on home gardens or lawns; (2)
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From page 83... ...
Santa Barbara, California N-Viro Toledo, Ohio Synox Corporation Jacksonville, Floride Ultra Clear, Inc. Marlboro, New Jersey 10% moisture content Two-phase thermophillic and mesophilic anaerobic digestion where pathogen criteria used to demonstrate PFRP (process for the further reduction of pathogens)
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From page 84... ...
For instance, if all land application should cease, how would the overall risk be altered if additional landfills, surface disposal sites, and incinerators were constructed and operated to accommodate the additional volumes? In response to EPA's benef~cial-use policy, the publication of risk-based regulations and the general trend toward recycling, numerous states began to encourage POTWs to use their biosolids in the late 1980s and 1990s.
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From page 85... ...
· Biosolids must be applied at a rate equal to or less than the agronomic nitrogen need of the crop to be grown. Some states require more stringent site criteria, including greater distances from surface waters, maximum slope restrictions, minimum depths to groundwater and bedrock, minimum and maximum soil permeability rates, minimum distances to residences or recreation areas, and minimum distances to private or public water-supply wells.
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From page 87... ...
87 to to to o o of Cal v o 4 o V)
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From page 88... ...
Three factors affect the potential dietary exposure to pathogens via crops through land application (EPA 1999b)
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From page 89... ...
Notably, federal statutes do not include groundwater in the definition of waters of the United States, and thus no minimum depth to groundwater or bedrock is included in federal regulations. However, at least 23 states include such requirements and at least 10 have prohibited land application of biosolids during winter months.
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From page 90... ...
Excess phosphorus often becomes a water-quality problem after it reaches surface waters, because it promotes accelerated algae growth and eutrophication. For these reasons, wastewater treatment plants are increasingly being forced to limit the phosphorus in their effluent discharge to surface waters.
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From page 91... ...
- 1 million dry tons of biosolids are land applied or publicly distributed as EN biosolids, representing 18% of the total amount used or disposed of.
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From page 92... ...
depict similar trends. In addition to the regulated pollutants within EPA's biosolids program, the pretreatment program is charged with controlling the 126 "priority pollutants," as well as any other incompatible pollutants from industries that discharge into the sewer systems, as described in the Clean Water Act KEPT 1999a)
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From page 94... ...
Current regulations in 40 CFR 761 state that land-applied biosolids with concentrations of total PCBs at less than 50 mg/kg are regulated under 40 CFR 503, and sewage sludge with concentrations greater than 50 mg/kg cannot be land applied and is subject to provisions within that regulation (EPA 1998~. Furthermore, 40 CFR 257 requires industrial sludge with concentrations of total PCBs at greater than 10 mg/kg to be injected or incorporated when land applied.
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From page 95... ...
, EPA cannot claim that the regulations are followed and that public health and the environment are protected as required by the CWA. States do, however, implement their own biosolids programs to some greater or lesser extent and actively participate in both compliance assistance and enforcement.
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From page 96... ...
· EPIC shouldprovide additior~alf~nds Not divertedf~r~dsJ to states to implement biosolids programs andfacilitate delegation' of authority to states to administer the federal biosolids regulations. · Resources are also neededforcond~cting research into emergir~giss~es and to revise the regulations as appropriate and in a time~fashiorl (e.g., molybdenum standards should be proposedJ.
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From page 97... ...
· Exemptionsirom nutrie''t management and site restrictions for land applicailon of balk EQ biosolids should be eliminated. There are several prescribed treatment processes that can be used to meet regulatory requirements for classifying biosolids as Class A or Class B
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From page 98... ...
The Tiff cier'qy of these methods arid their results should be cor'~idered ire conducting and ir~terpretir~gf~t~re risk assessments arid died to develop applicable risk-management technologies. The CWA requires EPA to establish biosolids regulations based on risk; however, it is important to acknowledge and consider other approaches to regulating land application of biosolids.
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From page 99... ...
1999. NIOSH Health Hazard Evaluation Report: BioSolids Land Application Process, LeSourdsville, Ohio.
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From page 100... ...
1989. Environmental Regulation and Technology: Control ofthe Pathogens in MunicipalWastewater Sludge for Land Application Under CFR Part 257.
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From page 101... ...
2002c. Land Application of Biosolids.
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From page 102... ...
2001. The role of municipalities in regulating the land application of sewage sludges and spetage.
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From page 103... ...
1994. Land application of sewage sludge: Scientific perspectives of heavy metal loading limits in Europe and the United States.
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From page 104... ...
2001. A modified risk assessment to establish molybdenum standards forland application of biosolids.
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From page 105... ...
Biosolids Management 105 of Wisconsin Department of Administration. "Online]
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