LAND APPLICATION OF DOMESTIC WASTEWATER TREATMENT FACILITY BIOSOLIDS,
BIOSOLIDS DERIVED PRODUCTS, AND DOMESTIC SEPTAGE
(1) It is the purpose of these rules and best management practices to protect the environment and public health in Oregon by prescribing the methods, procedures and restrictions required for the safe handling and use of domestic wastewater treatment facility solids, biosolids, biosolids derived products, and domestic septage. These rules implement a program for biosolids and domestic septage management which satisfies or exceeds minimum federal regulations pertaining to land application.
(2) Industrial process water solids, agricultural wastes and sewerage waste water are not included in these rules.
The Environmental Quality Commission (EQC) encourages the land application of treated domestic wastewater biosolids, biosolids derived products, and domestic septage which are managed in a manner which protects the public health and maintains or improves environmental quality. These beneficial recyclable materials improve soil tilth, fertility, and stability and their use enhances the growth of agricultural, silvicultural, and horticultural crops.
Unless otherwise indicated in this Division, definitions appearing under federal regulations 40 CFR §503.11, and §503.31 shall apply. In addition, as used in these rules, unless defferently required by context, the following definitions apply:
(1) "Agronomic Application Rate" means a rate of biosolids or domestic septage application which matches nutrient requirements for specific crop on an annual basis.
(2) "Beneficial Use Site" means any Department approved site for application of a regulated amount of biosolids or domestic septage used for crop or livestock production, soil reclamation and stabilization, or soil improvement. Application rates and site management practices shall assure continued agricultural, horticultural or silvicultural production and shall not lead to a temporary or long-term reduction in site productivity.
(3) "Biosolids" means solids derived from primary, secondary, or advanced treatment of domestic wastewater which have been treated through one or more controlled processes that significantly reduce pathogens and reduce volatile solids or chemically stabilize solids to the extent that they do not attract vectors. This term refers to domestic wastewater treatment facility solids that have undergone adequate treatment to permit their land application. This term has the same meaning as the term "sludge" in ORS 468B.095, and the term "sewage sludge" found elsewhere in OAR Chapter 340.
(4) "Biosolids Derived Products" means materials derived from composting domestic wastewater treatment facility solids or other processes, such as thermal drying, which result in a material which meets pollutant concentrations in 40 CFR §503.13(b)(3), the Class A pathogen requirements in 40 CFR §503.33(b)(1) to §503.33(b)(8). Biosolids derived products also include any soil amendments which, in part, contain biosolids meeting these criteria. Biosolids derived products are acceptable for distribution to the general public for immediate use.
(5) "Chemical Treatment" means the process of mixing lime or other chemicals with domestic wastewater solids or domestic septage to reduce the number of pathogens or amount of putrescible matter.
(6) "Composting" means a process by which domestic wastewater treatment facility solids, biosolids, or septage are mixed with carbonaceous material and aerated with controlled elevated temperatures to promote rapid decomposition and ultimate stabilization as well as pathogen reduction.
(7) "Controlled Access" means that public entry or traffic is unlikely, for example agricultural land that is privately owned. Parks or other public land may require fencing to ensure controlled access.
(8) "Domestic Wastewater Treatment Facility Solids" means the accumulated suspended and settleable solids of domestic wastewater, deposited in tanks or basins mixed with water to form a semi-liquid mass. Grit and screenings removed from domestic wastewater during preliminary treatment are not considered solids under this definition.
(9) "Department" means the Oregon Department of Environmental Quality (DEQ).
(10) "Dewatered Solids" means domestic wastewater treatment facility solids or biosolids with a solids concentration between 10 and 50 percent.
(11) "Domestic Septage" means liquid or solid material removed from a septic tank, cesspool, protable toilet, Type III marine sanitation device, holding tanks, or similar treatment works that receive only domestic wastewater. Domestic septage does not include liquid or solid material removed from a septic tank, cesspool, or similar treatment works that receive either commercial wastewater or industrial wastewater and does not include grease removed from a grease trap at a restaurant.
(12) "Domestic Wastewater" means the water-carried human wastes from residences, buildings, industrial establishments or other places, together with such groundwater infiltration and surface water as may be present that flow to wastewater treatment facilities.
(13) "Dried Solids" means domestic wastewater treatment facility solids or biosolids with a solids concentration of greater than fifty percent accomplished by mechanical means or air drying.
(14) "Exceptional Quality Biosolids" means domestic wastewater treatment facility solids containing trace pollutant concentrations which are below federal alternative pollutant limits recognized under 40 CFR §503.13(b)(3) that have been treated by a Class A pathogen reduction process recognized under 40 CFR §503.32(a) and one of the vector attraction reduction procedures established under 40 CFR §503.33(b)(1) through (8). These solids are recognized as soil amendments which are acceptable for distribution and marketing to the public.
(15) "Federal Regulations" means Part 503 Standards for the Use or Disposal of Sewage Sludge, Subchapter O in Chapter I of Title 40 of the Code of Federal Regulations (§503).
(16) "Liquid Biosolids" means domestic wastewater treatment facility biosolids with a solids concentration of less than ten percent.
(17) "Non-Digested Solids" means raw domestic primary, secondary, or advanced wastewater treatment facility solids, or solids that have accumulated in a digester which is either not operating efficiently or has not provided adequate time or temperature for digestion to occur; a lagoon where settled solids have not decomposed to the extent that they comply with 40 CFR §503.32 pathogen or 40 CFR §503.33vector attraction reduction requirements; or a septic tank process whose function is confinement and/or separation of liquids and solids.
(18) "NPDES Permit" means a waste discharge permit issued in accordance with requirements and procedures of the National Pollutant Discharge Elimination System authorized by the Federal Clean Water Act and of OAR chapter 340, division 45.
(19) "Person" means the United States and agencies thereof, any state, any individual, public or private corporation, political subdivision, governmental agency, municipality, co-partnership, association, firm, trust, estate or any other legal entity whatever.
(20) "Site Authorization Letter" means a Department issued document which establishes minimum site management conditions for applying biosolids to a specific land application site.
(21) "Raw Sewage Sludge" means non-decomposed or non-oxidized sewage sludge.
(21) "Sludge" or "Sewage Sludge" -- See Biosolids.
(22) "Treatment" means the alteration of the quality of domestic wastewater, wastewater derived solids, or septage by physical, chemical or biological means or a combination thereof, such that the tendency of said liquids or solids to cause any degradation in water quality or other environmental conditions is reduced.
(23) "WPCF Permit" means a Water Pollution Control Facility permit issued by the Department in accordance with the procedures of OAR Chapter 340, Division 14 or OAR Chapter 340, Division 71 and which is not an NPDES Permit.
Permit or License Required
(1) Any person engaged in domestic wastewater collection, or treatment processes where domestic wastewater treatment facility solids, biosolids derived products, or domestic septage are produced and subsequently land applied or disposed, must have in their possession either a valid NPDES or WPCF permit obtained pursuant to ORS 468B.050; or a Solid Waste Disposal permit obtained for a specific site as provided by ORS 459.205 or a valid sewage disposal service license issued pursuant to ORS 454.695.
(2) Any person who prepares a biosolids derived product pursuant to 40 CFR §503.7 which includes domestic wastewater treatment facility solids, biosolids, or domestic septage, shall have in their possession a valid NPDES or WPCF permit issued pursuant to ORS 468B.050.
(3) Persons who land apply either Bulk Class B biosolids derived from sources outside Oregon or alkaline stabilized domestic septage shall first obtain a valid WPCF permit obtained pursuant to ORS 468B.050.
(4) Permit or license issuance or renewal applicants shall submit a biosolids or domestic septage management plan to the Department developed pursuant to OAR 340-050-0031. No plan shall be approved by the Department unless, at a minimum, the plan demonstrates compliance with all requirements specified under OAR 340-050-0020.
(5) Conditions in Department biosolids and septage management plan approvals and site authorization letters may be appealed to the Commission pursuant to ORS Chapter 183 and OAR chapter 340, Division 11. Appeals shall be limited to topics pertaining to Department approved biosolids or septage management plan or site authorization letters.
(6) Any person operating a sewage disposal service business shall comply with all license conditions required under Department approved septage management plans.
(7) Where biosolids will be land applied during the term of a permit, permit applications submitted to the Department shall include a land application plan developed pursuant to 40 CFR §501.15 and OAR 340-050-0031(7).
(8) Biosolids management and land application plans shall be subject to review and comment during the public participation process required prior to permit issuance or renewal under OAR 340-014-0025, OAR 340-045-0035, or OAR 340-071-0162.
(9) All conditions contained in Department approved biosolids or septage management plan approval and site authorization letters are considered permit requirements.
(10) Except as otherwise required by this Division, the permitting provisions in 40 CFR Part 122; 40 CFR Part 501; OAR Chapter 340, Division 14; OAR Chapter 340, Division 45; and OAR Chapter 340, Division 71 are applicable.
It is the responsibility of the permittee and/or licensee to ensure the proper handling of all domestic wastewater treatment facility solids, biosolids and domestic septage generated or pumped. Transportation of domestic treatment facility wastewater solids, biosolids and septage to domestic wastewater treatment facilities; permitted septage pits, ponds or lagoons; or solids land application sites shall be achieved in a manner which prevents leaking or spilling of the solids onto the highways, streets, roads, waterways, or other land surfaces not approved for solids application or disposal.
Limitations and Restricted Uses
(1) Written authorization must be obtained from the Department prior to burial, containment or direct soil incorpor-ation of raw and/or non-digested wastewater treatment facility solids.
(2) Biosolids or biosolids derived products shall not be given or sold to the public without their knowledge as to its origin. Biosolids analysis shall be available on request from the wastewater treatment facility.
(3) Biosolids land application to agricultural or forest land, or a public contact site, shall not exceed the nitrogen loading required (agronomic loading rate) for maximum crop yield.
(4) On a case-by-case basis, at reclamation sites, the Department may allow a single application of biosolids which is sufficient to supply enough organic matter to establish a vegetative cover. Application rates at these sites may exceed the short-term agronomic loading rate of the vegetation established.
(5) On a case-by-case basis, the Department may impose conditions or limitations for the beneficial use of biosolids or domestic septage which are more stringent than the requirements specifically contained in this Division where it considers additional requirements necessary to protect the public health and environment.
(1) Unless the Department determines that the context requires otherwise, all general provisions of 40 CFR §503.1 through §503.9 and land application requirements in 40 CFR §503.10 through §503.18 are applicable for the purpose of this rule.
(2) To be considered acceptable for land application, biosolids or domestic septage shall meet:
(a) Pollutant concentration and cumulative pollutant loading limits required under 40 CFR §503.13. (Note: not required for domestic septage.);
(b) One of the pathogen reduction standards established under 40 CFR §503.32;
(c) One of the vector attraction reduction standards required under 40 CFR §503.33; and
(d) Management practices required under 40 CFR §503.14 and 40 CFR §503.32(b)(5).
(3) In addition to meeting pollutant concentration and loading limits required under 40 CFR §503.13, biosolids derived products must meet federal Class A pathogen reduction standards pursuant to 40 CFR §503.32(a) and one of the vector attraction reduction standards required under 40 CFR §503.33(b)(1) through (8).
(4) Biosolids imports must meet the following criteria;
(a) 40 CFR §503.13(b)(1), Table 1 pollutant ceiling concentration limits;
(b) One of the 40 CFR §503.32(b) Class B pathogen reduction standards;
(c) One of the 40 CFR §503.33(b)(1) through (8) vector attraction reduction standards;
(d) Minimum biosolids quality requirements of the County, State, or Regional government where they are produced; and
(e) They must be applied within beneficial use (agronomic) rates.
(5) Prior to land application, domestic septage shall be screened to ensure the removal of hair, plastics, and other coarse materials. Screenings shall be disposed at a permitted solid waste landfill. Further, septage shall undergo the following additional treatment prior to land application:
(a) Domestic septic tank pumpings: The pH of the domestic septage shall be increased by introducing and actively mixing sufficient alkaline agent to elevate the pH to 12 or higher (without further addition of alkaline agent) for a minimum period of 30 minutes.
(b) Domestic holding tank, chemical toilet, and vault toilet pumpings:
(A) Prior to alkaline stabilization, domestic holding tank, chemical toilet, or vault toilet pumpings shall be mixed with domestic septic tank pumpings at a ratio of at least three gallons septic tank pumpings per gallon holding tank, vault toilet, or chemical toilet pumpings.
(B) The pH of blended domestic septage shall be increased to 12 or more by introducing and actively mixing sufficient alkaline agent to elevate the pH to 12 or more (without further addition of alkaline agent) for minimum period of 2 hours. At the end of the active mixing process, the domestic septage-alkaline agent mixture shall be allowed to further react for at least 22 additional hours. At the end of the 22-hours reaction process, the pH of the domestic septage-alkaline agent mixture shall be at least 11.5.
(6) When biosolids will be applied above normal agronomic rates for the purpose of land reclamation, the Department may require that an evaluation for potential groundwater quality impacts be conducted in accordance with OAR Chapter 340, Division 40. If the Department determines the application rate proposed could cause an adverse impact on groundwater quality, a groundwater quality protection program shall be required pursuant to OAR 340-040-0030.
Biosolids and Domestic Septage Land Application Site Selection and Approval
(1) Prior approval must be obtained in writing from the Department for the land application of biosolids or domestic septage on beneficial use sites or disposal sites.
(2) Prior to approval of any proposed site that may be sensitive with respect to residential housing, runoff potential or threat to groundwater, the Department shall ensure that an opportunity is provided for public comment and, if required as noted in (a) below, public hearing.
(a) If, during the public comment period, at least 10 people, or an organization representing at least 10 people, indicate concerns about the proposed action, then opportunity shall be provided for public hearing.
(b) The Department shall take final action on site authori-zation within 30 days of the closure of the public comment period, or 30 days of the closure of the hearing's record.
(3) Land application site authorization letters are considered an integral part of the biosolids or domestic septage management plan. Provisions specified by the Department in site authorization letters, in accordance with a Department approved biosolids or domestic septage management plan, shall be considered enforceable conditions under the permitted source's NPDES, WPCF, or Solid Waste Disposal permit.
Biosolids and Domestic Septage Management Plans
(1) Any person who intends to land apply biosolids or domestic septage shall submit a solids management plan to the Department for review and approval. Unless otherwise authorized in writing by the Department, solids management plans shall be submitted a minimum of 60 days before biosolids land application commences.
(2) Provisions established in Department approved biosolids or domestic septage management plans shall be considered NPDES, WPCF, or Solid Waste Disposal permit conditions.
(3) The biosolids or domestic septage management plan shall be kept current and remain on file with the permit or license. Plan modification requires written Department approval.
(4) Septage management plans must address the quantities of septages handled annually, types of septage processed, solid storage facilities, and solids land application or disposal facilities.
(5) Biosolids and domestic septage management plans must include:
(a) A description of the method(s) of solids removal;
(b) For wastewater and septage treatment facilities, a detailed description of the wastewater processing facility, including unit processes used in wastewater treatment; source design flow (gpd); and wastewater flow origin (e.g., percent domestic, industrial, commercial, and domestic septage);
(c) An indication of how primary, secondary, and tertiary solids or septages are removed, thickened, digested, and dewatered;
(d) A description of the quantities of raw and stabilized solids volumes generated annually;
(e) The means used to attain pathogen reduction, and data confirming pathogen reduction has been accomplished;
(f) The method(s) for determining degree of solids stability, and data supporting means of stabilization;
(g) The projected use and volume of solids storage basins (if appropriate) and a description of additional treatment which occurs during storage;
(h) A description of the means used to transport, temporarily store (if applicable), and apply biosolids or domestic septage at Department authorized land spreading sites;
(i) A description of biosolids monitoring and sampling program and biosolids analysis, including but not limited to nitrate-nitrogen, ammonia nitrogen, total Kjeldahl nitrogen (TKN), phosphorus, potassium, total solids, volatile solids, arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, zinc, and pH. (Note: Septage management plans do not require these analyses.);
(j) The delineation of land application site selection criteria, crops and crop assimilative capacity (nitrogen), and site management practices, including but not limited to annual and long-term application rates, and testing and sampling;
(k) The identification of all Department authorized biosolids or domestic septage land application sites;
(l) A description of biosolids or domestic septage land application site monitoring, recordkeeping, and reporting procedures; and
(m) A description of remedial procedures that would be implemented in the event of a solids treatment process failure (e.g., digester breakdown or upset), solids spill at the wastewater treatment facility or solids generating source, or biosolids or domestic septage spill between the generating source and land application site.
(6) New Department authorized sites shall be made a part of the biosolids or domestic septage management plan.
(7) Biosolids Land Application plans shall, at a minimum, list:
(a) All known sites that will receive biosolids during the life of the permit;
(b) The geographic location of new sites which are not specifically listed at the time of application;
(c) Criteria which will be used in the selection of new sites; and
(d) Management practices which will be implemented where new sites are authorized by the Department.
Biosolids Facilities Plans and Specifications
(1) Plans and specifications for biosolids or domestic septage impoundments, reservoirs, tanks, or other containment structures proposed for storage may be required by the Department as part of an upgrade or as a permit or solids management plan approval condition.
(2) Detailed plans and specifications for biosolids or septage composting facilities shall, at a minimum, meet requirements included under OAR 340-096-0020.
(3) Plans and preliminary engineering reports must be submitted to the Department pursuant to OAR 340-052-0015. Written Department approval shall be obtained prior to the construction or use of biosolids or septage storage or composting facilities.
Monitoring Recordkeeping and Reporting
(1) The permittee shall provide the Department with biosolids analyses and maintain a log indicating the quantity, quality, and location of biosolids applied to Department approved sites. The site application log shall become a condition of the site authorization letter and must be available for Department review during the life of the application site. Site logs shall be maintained as part of the permittee's permanent records.
(2)(a) Biosolids analyses shall be performed on a representative sample and shall include but not be limited to, all pollutants listed in 40 CFR §503.13(b)(3) Table 1 and the following:
(F) Total Kjeldahl Nitrogen (TKN) -- % dry weight;
(G) Nitrate Nitrogen (NO3-N) -- % dry weight;
(H) Ammonium Nitrogen (NH4-N) -- % dry weight;
(I) Total Phosphorous (P) -- $ dry weight;
(J) Potassium (K) -- % dry weight;
(K) pH -- standard units;
(L) Total Solids -- % dry weight;
(M) Volatile Solids -- % dry weight.
(b) All tests shall be performed using sampling and analytical methods established under 40 CFR §503.8; the Environmental Protection Agency's (EPA) POTW Sludge Sampling and Analysis Attraction in Sewage Sludge (EPA/625/R-52/013) guidance (1992), and EPA's POTW Sludge Sampling Procedures and Protocols for the National Sewage Sludge Survey (1989) document.
(c) Sampling locations and frequency shall be representative of the quality and quantity of biosolids generated, but in no case, unless otherwise authorized in writing by the Department, less frequent than required under 40 CFR §503.16, Table 1.
(3) Recordkeeping requirements shall conform to 40 CFR §503.17.
(4) Domestic Wastewater Treatment Facilities that produce biosolids with one or more trace pollutants whose annual average pollutant concentration exceeds 40 CFR §503.13(b)(3) limits (based on a 95 percent confidence interval), shall track cumulative pollutant loading pursuant to 40 CFR §503.13(b)(2), Table 2 and maintain records adequate to demonstrate that pollutant additions do not exceed Table 2limits.
(5) Unless otherwise required by the Department, the quality and quantity of biosolids and land application actions shall be reported to the Department at least once annually. The Department may require more frequent reporting on biosolids production, treatment, characteristics, and land application activities. Monthly reporting is not required where exceptional quality biosolids are land applied.
(6) Annually, by February 19, each domestic NPDES, WPCF, and Solid Waste permitted source that has generated and land applied bulk biosolids or domestic septage, or prepared biosolids or biosolids derived products for distribution and marketing during the prior year, shall provide the Department with a comprehensive report that describes solids handling activities for the previous year. At a minimum, the report shall include, but is not limited to:
(a) Data, on each site that received solids, which is adequate to characterize solids quality and to demonstrate that solids were applied within agronomic loading rates and other required site management practices.
(b) Sources generating and applying biosolids that are required to track cumulative pollutant additions pursuant to 40 CFR §503.13(b)(2), Table 2, shall also be required to submit information on annual and cumulative pollutant additions;
(c) Information sufficient to demonstrate that solids met pathogen reduction requirements required under 40 CFR §503.32 and vector attraction reduction standards required under 40 CFR §503.33;
(d) Information describing any substantive modifications to solids handling or land application site management practices;
(e) A detailed description of any violation of 40 CFR §503 or OAR Chapter 340, Division 50 and remedial actions taken to prevent the recurrence of similar violations in the future.
(7) Annually, as a requirement of license renewal, sewage disposal service businesses shall submit information adequate to characterize solids handling activities which occurred during the previous licensing period. Information must include data describing the quantities and varieties of septages handled and locations where solids are used and disposed.
The following best management practices are meant to provide assistance in the development of environmentally acceptable biosolids and domestic septage use programs. They convey many of the criteria considered by the Department to be important in the use, site selection and application of domestic wastewater treatment facility biosolids, biosolids derived products, and domestic septage.
(1) The quantity of bulk biosolids or domestic septage applied to any Department authorized land spreading sites shall not exceed the agronomic rate for the particular cultivar grown. Best management practices are recommended where exceptional quality biosolids are land applied.
(2) Where bulk biosolids and domestic septage are applied for agricultural use, nitrogen requirements for particular crops can be obtained from the Oregon State University Extension Service.
(3) Biosolids and domestic septage shall be applied at rates and methods which prevent the occurence of runoff, erosion, leaching, and nuisance conditions, or the likelihood of groundwater contamination.
(4) Controlled access to bulk Class B domestic biosolids and domestic septage land application sites is required for a minimum of 12 months following surface application of solids. Access control is assumed on rural private land.
(5) As a general rule, crops grown for direct human consumption (fresh market fruits and vegetables) should not be planted for at least 14 months after bulk Class B biosolids or domestic septage application. If the edible parts will not be in contact with the Class B biosolids or domestic septage amended soil, or if the crop is to be treated or processed prior to marketing such that pathogen contamination is not a concern, this requirement may be waived for root crops pursuant to §503.32(b)(5). No time restrictions are required where Class A biosolids derived products are land applied to sites used for the cultivation of fresh market fruits or vegetables.
(6) Grazing animals should not be allowed on pasture or forage nor should livestock feed crops be harvested where bulk Class B biosolids or domestic septage have been applied for a minimum of 30 days after application.
(7) Exceptional Quality biosolids and biosolids derived products may be used on indoor and outdoor ornamental plants, shrubs, trees, home gardens and lawns, and high public contact areas without restricting public access.
Criteria for Site Selection and Approval
(1) Normally, tillable agricultural land is suitable for the land application of biosolids and domestic septage.
(2) To be considered for biosolids or domestic septage land application, sites should meet all the following conditions:
(a) Sites should be on a stable geologic formation not subject to flooding or excessive runoff from adjacent land. If periodic flooding cannot be avoided, the period of application should be restricted and soil incorporation is recommended.
(b) At the time when liquid biosolids or domestic septage are applied, the minimum depth to permanent groundwater should be four feet and the minimum depth to temporary groundwater should be one foot. Sites approved for year-round application should be evaluated carefully to ensure that groundwater separation distances conform with these requirements.
(c) Topography of the site should be suitable to allow normal agricultural operations. Where needed, runoff and erosion control measures should be constructed. In general, liquid biosolids or domestic septage should not be surface applied on bare soils where the ground slope exceeds 12 percent. Well vegetated sites with slopes up to 30 percent may be used for dewatered or dried biosolids, or for liquid biosolids or domestc septage application with appropriate management to prevent runoff.
(d) Soil should have a minimum rooting depth of 24 inches. The underlying substratum to at least 24 inches should not be rapidly draining so that leachate will not be short circuited to groundwater.
(e) Sites with saline and/or sodic soils should be avoided.
(3) Discretion should be used in approving application of biosolids or domestic septage on land that is in close proximity to residential areas.
(a) A buffer strip large enough to prevent nuisance odors or wind drift is needed. Size of the buffer strip will be determined by the Department on a case-by-case basis and depend upon the method of application used, total solids content, and proximity to sensitive areas, for example:
(A) Direct injection: no limit required;
(B) Truck spreading (liquid): 0 to 200 feet;
(C) Spray irrigation: 50 to 500 feet;
(D) Cake or dried solids: 0 to 50 feet.
(b) Buffer strips should be provided along well traveled highways. The size of the buffer strip will vary with local conditions and should be left to the discretion of the Department field representative.
(c) No bulk Class B biosolids or domestic septage should be spread at the site closer than 50 feet to any ditch, channel, pond or waterway or within 200 feet of a domestic water source or well.
Application of Biosolids and Domestic Septage
(1) Biosolids analyses offer a guide to determine the annual application rate for a particular crop; ascertain whether cumulative pollutant tracking is required; and establish that solids are sufficiently stable to comply with pathogen and vector attraction reduction standards required under 40 CFR §503.32 and 40 CFR §503.33, respectively.
(1) The application of biosolids or domestic septage on agricultural land should be managed to utilize the fertilizer and organic matter value to the maximum extent possible. The recommended rate of biosolids or domestic septage application is normally based on the nitrogen requirement of the crop grown and will vary depending on the nitrogen content of the solids.
(3) Crop nitrogen requirements are used routinely to determine application rates for commercial fertilizer and these figures are readily available from state or county Extension Service offices. Applying biosolids and domestic septage within these limits helps ensure that solids nitrogen will be utilized for plant growth and that excess nitrogen which could leach into groundwater will not be of concern.
(4) Exceeding crop nitrogen requirements may occasionally be justified on a temporary basis in order to achieve rapid soil improvement or to prolong beneficial effects. Biosolids applications exceeding normal crop nitrogen requirements may be approved on a case-by-case basis for reclamation or soil improvement, if justification for a single high rate application is provided to the Department.
(a) Where a site has previously been amended with biosolids at soil improvement or reclamation rates, documentation of background soil nitrate-nitrogen (NO3-N) shall be submitted for Department approval prior to the application of additional biosolids;
(b) Soil samples shall be collected and tested according to protocols published by Oregon State University and the American Society of Agronomy.
(5) Sites proposed for routine annual application at agronomic rates must periodically be assessed to determine the impact of nitrogen from biosolids and other sources.
(a) The criteria for requiring evaluation or performance monitoring [e.g., soil testing for carry-over nitrate-nitrogen (NO3-N)] will be biosolids applicatoins exceeding 2 out of 3 successive years at agronomic rates;
(b) Soil samples shall be collected and tested according to protocols published by Oregon State University and the American Society of Agronomy.
Oregon State Archives • 800 Summer St. NE • Salem, OR 97310