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HomeMy WebLinkAboutWQ0002617_Final Permit_19930329State of North Carolina Department of Environment, Health and Natural Resources Division of Environmental Management 512 North Salisbury Street • Raleigh, North Carolina 27604 James B. Hunt, Jr., Governor March 29, 1993 Mr. Steve Smith, Town Administrator Town of Stoneville Post Office Box 71 Stoneville, North Carolina 27048 Jonathan B. Howes, Secretary Subject: Permit No. WQ0002617 Amendment Town of Stoneville Land Application of Sludge Rocldngham County Dear Mr. Smith: In accordance with your application received August 14, 1992, we are forwarding herewith Permit No. WQ0002617 as amended, dated March 29, 1993, to the Town of Stoneville for the continued operation of a land application of sludge program. This permit amendment consists of adding approximately 94.01 acres to the existing land application program. Please be advised of condition 1115 which states that no land application of the sludges included in this permit shall commence unless the permittee can demonstrate the the process to significantly reduce pathogens is met. The permittee shall maintain records which show that the sludges prior to land application when conducted by agitating sludge with air or oxygen maintained aerobic conditions at residence times ranging from 60 days at 150C to 40 days at 20aC or when conducted in the absence of air maintain residence times ranging from 60 days at 200C to 15 days at 350C. This permit shall be effective from the date of issuance until December 31, 1994 and shall void Permit No. WQ0002617 issued February 7, 1990, and shall be subject to the conditions and limitations as specified therein. Please pay particular attention to the monitoring requirements in this permit. Failure to establish an adequate system for collecting and maintaining the required operational information will result in future compliance problems. Regional Offices Asheville Fayetteville Mooresville Raleigh Washington Wilmington Winston-Salem 704/251-6208 919/486-1541 704/663-1699 919/57IA700 9191946-6481 919/395-3900 919/896-7007 Pollution Prevention Pays P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone 919-733-7015 An Equal Opportunity Affirmative Action Employer If any parts, requirements, or limitations contained in this permit are unacceptable to you, you have the right to request an adjudicatory hearing upon written request within 30 days following receipt of this permit. This request must be in the form of a written petition, conforming to Chapter 150B of North Carolina General Statutes, and filed with the Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this permit shall be final and binding. If you need additional information concerning this matter, please contact,l Angela Y. Gxiffin at 919/ 733-5083. Sincerely, i` _ L A. Pre r n Howard, Jr., P.E. Director cc: Rockingham County Health Department EWR, Inc. Winston-Salem Regional Office, Water Quality Section Winston-Salem Regional Office, Groundwater Section Jacks Floyd, Groundwater Section Central Office Training and Certification Facilities Assessment Unit NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION DEPARTMENT OF ENVIRONMENT, HEALTH AND NATURAL RESOURCES RALEIGH SLUDGE LAND APPLICATION PERMIT In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as amended, and other applicable Laws, Rules, and Regulations PERMISSION IS HEREBY GRANTED TO Town of Stoneville Rockingham County FOR THE continued operation of a sludge land application program consisting of the application of approximately 91.5 dry tons per year of sludge from the Town of Stoneville wastewater treatment facility to approximately 143.26 acres of land in Rockingham County with no discharge of wastes to the surface waters, pursuant to the application received August 14, 1992 and in conformity with the project plan, specifications, and other supporting data subsequently filed and approved by the Department of Environment, Health and Natural Resources and considered a part of this permit. This permit shall be effective from the date of issuance until December 31, 1994 and shall void Permit No. WQ0002617 issued February 7, 1990, and shall be subject to the following specified conditions and limitations: The Winston-Salem Regional Office, telephone number (919) 896-7007, and the appropriate local governmental official (county manager/city manager) shall be notified at least twenty-four (24) hours prior to the initial application of the sludge so that an inspection can be made of the application sites and application method. Such notification to the regional supervisor shall be made during the normal office hours from 8:00 a.m. until 5:00 p.m. on Monday through Friday, excluding State Holidays. Also the Rockingham County Manager's office must be notified prior to the initial application so that they will be aware that the operation has commenced. 2. This permit shall become voidable if the soils fail to adequately absorb the wastes and may be rescinded unless the sites are maintained and operated in a manner which will protect the assigned water quality standards of the surface waters and ground waters. 3. The land application program shall be effectively maintained and operated as a non - discharge system to prevent the discharge of any wastes resulting from the operation of this program. 1. The facilities and disposal sites shall be properly maintained and operated at all times. 2. A suitable vegetative cover as listed in condition H 3, shall be maintained in accordance with the crop management plan approved by this Division. 3. The application rates shall not exceed the following for the specified crops: Crop PAN (lbs/acre/year) Corn 200 Fescue 250 Pasture 200 Soybeans 100 Small Grains 100 4. No sludges other than the following are hereby approved for land application in accordance with this permit: Permit Estimated Source County Number -Volume( dry tons/year) Town of Stoneville Rockingham NC0028011 91.5 VVVVTP 5. The lifetime heavy metal loadings shall not exceed the following for the corresponding Cation Exchange Capacities (CEC): Lifetime Loadings (lbs/acre) Parameter CEC < 5 CEC 5 - 15 CEC > 1 Lead 500 1000 2000 Zinc 250 500 1000 Copper 125 250 500 Nickel 125 250 500 Cadmium 4.5 9 18 6. Upon classification of the facility by the Certification Commission, the Permittee shall employ a certified wastewater treatment plant operator to be in responsible charge (ORC) of the wastewater treatment facilities. The operator must hold a certificate of the type and grade at least equivalent to or greater than the classification assigned to the wastewater treatment facilities by the Certification Commission. The Permittee must also employ a certified back-up operator of the appropriate type and grade to comply with the conditions of Title 15A, Chapter SA, .0202. The ORC of the facility must visit each Class I facility at least weekly and each Class H, III, and IV facility at least daily, excluding weekends and holidays, and must properly manage and document daily operation and maintenance of the facility and must comply with all other conditions of Title 15A, Chapter 8A, .0202. 7. Adequate procedures shall be provided to prevent surface runoff from carrying any disposed or stored sludge material into any surface waters. 8. Animals shall not be grazed on sludge applied land within a 30-day period following the sludge application. Application sites that are to be used for grazing shall have fencing that will be used to prevent access after each application. 9. Surface applied sludge will be plowed or disced within twenty-four (24) hours after application on lands with no cover crop established- 3 10. For areas that are prone to flooding or within the 100-year flood elevation, sludge may be applied only during periods of dry weather. The sludge must be incorporated into the soil within twenty-four (24) hours of application. 11. Appropriate measures must be taken to control public access to the land application sites during active site use and for the 12-month period following the last sludge application event. Such controls may include the posting of signs indicating the activities being conducted at each site. 12. Adequate provisions shall be taken to prevent wind erosion and surface runoff from conveying pollutants from the sludge application area onto the adjacent property or into the surface waters. 13. Sludge shall not be applied in inclement weather or until 24 hours following a rainfall event of 1/2-inch or greater in 24 hours. Any emergency sludge disposal measures must fast be approved by the Division of Environmental Management. 14. The site shall be adequately limed to a soil pH of at least 6.5 prior to sludge application. Sludge may be applied to sites with a pH of less than 6.5 provided a sufficient amount of lime is also applied to achieve a final pH of the lime, sludge and soil mixture of at least 6.5. 15. No land application of the sludges included in this permit shall commence unless the permittee can demonstrate the the process to significantly reduce pathogens is met. The permittee shall maintain records which show that the sludges prior to land application when conducted by agitating sludge with air or oxygen maintained aerobic conditions at residence times ranging from 60 days at 150C to 40 days at 200C or when conducted in the absence of air maintain residence times ranging from 60 days at 200C to 15 days at 350C. 1. Any monitoring (including groundwater, surface water, sludge, soil, or plant tissue analyses) deemed necessary by the Division of Environmental Management to insure protection of the environment will be established and an acceptable sampling and reporting schedule shall be followed. If monitoring data indicates minimal or no concern to the Division, reduction of monitoring requirements may be pursued after two annual reporting periods. 2. Proper records shall be maintained by the Permittee tracking all disposal activities. These records shall include, but are not necessarily limited to the following information: a) source of sludge b) date of sludge application c) location of sludge application (site, field, or zone #) d) method of application e) weather conditions f) soil conditions g) type of crop or crop to be grown on field h) volume of sludge applied in gallons/acre and dry tons/acre i) annual and cumulative totals of dry tons/acre of sludge, annual and cumulative pounds/acre of each heavy metal (which shall include, but not be limited to lead, nickel, cadmium, copper and zinc), annual pounds/acre of plant available nitrogen (PAN), and annual pounds/acre of phosphorus applied to each field. 2 3. A representative annual soils analysis (Standard Soil Fertility Analysis) shall be conducted of each site receiving sludge in the respective calendar year and the results maintained on file by the Permittee for a minimum of five years. The Standard Soil Fertility Analysis shall include, but is not necessarily limited to, the following parameters: % Base Saturation Magnesium Phosphorus Potassium Lead1 Zincl pH Manganese Cation Exchange Capacity Sodium Nickell Cadmiuml Copperl Calcium l Soils analysis for these parameters shall be conducted once prior to permit renewal on soils from each site which has received sludge during the permit cycle. 4. A quarterly sludge analysis and annual Toxicity Characteristics Leaching Procedure (TCLP) analysis shall be conducted by the Permittee and the results maintained on file by the Permittee for a minimum of five years. If land application occurs at a frequency less than quarterly, sludge analysis will be required for each instance of land application. The sludge analysis shall include but is not necessarily limited to the following parameters: % total solids Magnesium Chlorides Sulfate Phosphorus Potassium Lead Zinc Copper Nickel Cadmium Chromium Sodium Calcium Total Nitrogen Ammonia Nitrogen Nitrate/Nitrite Nitrogen pH Plant Available Nitrogen (by calculation) The TCLP analysis shall include the following parameters: Arsenic Barium Benzene Cadmium Carbon tetrachloride Chlordane Chlorobenzene Chloroform Chromium o-Cresol m-Cresol p-Cresol Cresol 2,4-D 1,4-Dichlorobenzene 1,2-Dichloroethane 1, 1 -Dichloroethylene 2,4-Dinitrotoluene Endrin Heptachlor (and its hydroxide) Hexachlorobenzene Hexachloro-1,3-butadiene Hexachloroethane Lead Lindane Mercury Methoxychlor Methyl ethyl ketone Nitrobenzene Pentachlorophenol Pyridine Selenium Silver Tetrachloroethylene Toxaphene Trichloroethylene 2,4,5-Trichlorophenol 2,4,5-Trichlorophenol 2,4,5-TP (Silvex) Vinyl chloride E 5 . All sludges included in this permit must be monitored for compliance with condition 110 of this permit. Data to verify stabilization by a process to significantly reduce pathogens (as described in 40 CFR Part 257, Appendix II) must be maintained by the Permittee. The required data is specific to the stabilization process utilized, but should be sufficient to clearly demonstrate compliance with 40 CFR Part 257. 6. Three copies of all monitoring and reporting requirements as specified in conditions 1111, III 2, III 3, III 4, and lII 5 shall be submitted annually on or before March 1 of the following year to the following address: NC Division of Environmental Management Water Quality Section Facility Assessment Unit PO Box 29535 Raleigh, NC 27626-0535 7. Noncompliance Notification: The Permittee shall report by telephone to the Winston-Salem Regional Office, telephone number (919) 896-7007, as soon as possible, but in no case more than 24 hours or on the next working day following the occurrence or first knowledge of the occurrence of any of the following: a. Any occurrence with the land application program which results in the land application of significant amounts of wastes which are abnormal in quantity or characteristic. b. Any failure of the land application program resulting in a release of sludge material to receiving waters. c. Any time that self -monitoring information indicates that the facility has gone out of compliance with the conditions and limitations of this permit or the parameters on which the system was designed. d. Any process unit failure, due to known or unknown reasons, that render the facility incapable of adequate sludge treatment. e. Any spillage or discharge from a vehicle or piping system transporting sludge to the application site. Persons reporting such occurrences by telephone shall also file a written report in letter form within 15 days following first knowledge of the occurrence. This report must outline the actions taken or proposed to be taken to ensure that the problem does not recur. 1. Any groundwater quality monitoring as deemed necessary by the Division of Environmental Management shall be provided. 2. No land application of waste activities shall be undertaken when the seasonal high water table is less than three feet below land surface. VAINEFOU VWWWORIM The Permittee or his designee shall inspect the sludge storage, transport, and disposal facilities to prevent malfunctions and deterioration, operator errors and discharges which may cause or lead to the release of wastes to the environment, a threat to human health, or a nuisance. The Permittee shall keep an inspection log or summary including at least the date and time of inspection, observations made, and any maintenance, repairs, or corrective actions taken by the Permittee. This log of inspections shall be maintained by the Pernttee for a period of three years from the date of the inspection and shall be made available upon request by the Division of Environmental Management or other permitting authority. 2. Any duly authorized officer, employee, or representative of the Division of Environmental Management may, upon presentation of credentials, enter and inspect any property, premises or place on or related to the disposal site and facility at any reasonable time for the purpose of determining compliance with this permit; may inspect or copy any records that must be kept under the terms and conditions of this permit; or may obtain samples of groundwater, surface water, or leachate. :: I WKIJ►! f► 1. This permit shall become voidable unless the land application activities are carried out in accordance with the conditions of this permit and in the manner approved by this Division. 2. This permit is effective only with respect to the nature and volume of wastes described in the application and other supporting data. 3. This permit is not transferable. In the event there is a desire for the facilities to change ownership or a name change of the Permittee, a formal permit request must be submitted to the Division of Environmental Management accompanied by an application fee, documentation from the parties involved, and other supporting materials as may be appropriate. The approval of this request will be considered on its merits and may or may not be approved. 4. This permit shall become voidable unless the agreements between the Permittee and the landowners/lessees are in full force and effect 7 5. The following are approved sites for sludge application (see attached map(s)): Site Field Application Number County Owner/Lessee Number Areal acres 1 Rockingham Ralph Leake 1-6 36.54 2 Rockingham Arnold Johnson 7-9 12.71 STl Rockingham Dorothy Treadway 1 3.00 2 3.95 3 8.90 4 2.10 5 3.00 ST2 Rockingham William Treadway 1 16.00 ST3 Rockingham Jack Rakestraw 1 3.90 2 4.90 3 9.80 4 8.1 5 13.80 6 1.56 ST4 Rockingham Earl McCollum 1 15.00 Total 143.26 1 - Application Area excludes buffer areas. 6. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to an enforcement action by the Division of Environmental Management in accordance with North Carolina General Statute 143-215.6A to 143-215.6C. 7. The annual administering and compliance fee must be paid by the Permittee within thirty (30) days after being billed by the Division. Failure to pay the fee accordingly may cause the Division to initiate action to revolve this permit as specified by 15 NCAC 2H .0205 (c)(4). 8. The issuance of this permit does not preclude the Permittee from complying with any and all statutes, rules, regulations, or ordinances which may be imposed by other government agencies (local, state, and federal) which have jurisdiction. 9. A set of approved documents for the subject project must be retained by the applicant for the life of the permit. 10. The Perminee, at least six (6) months prior to the expiration of this permit, shall request its extension. Upon receipt of the request, the Commission will review the adequacy of the facilities described therein, and if warranted, will extend the permit for such period of time and under such conditions and limitations as it may deem appropriate. 11. This permit may be modified, or revoked and reissued to incorporate any conditions, limitations and monitoring requirements the Division of Environmental Management deems necessary in order to adequately protect the environment and public health. Permit issued this the 29th day of March, 1993 NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION 00rr(�" (:�Scm , /L A. Presto oward, Jr., .E., Director Division o nvironmental Management By Authority of the Environmental Management Commission Permit No. WQ0002617 Amendment 9 RATING SCALE FOR CLASSIFICATION OF FACILITIES Name of Plant: a L� rp Owner or Contact Person: S .Mailing Address: Aso 6�x 7t s 4-r,-, e- v. tp— ,-/, c. 0 County: Telephone: 41 5 - 573 - 9J 9 NPDES Permit No. WC00,2 ro !( Nondisc. Per. No. lssueDate: /G / Expiration Date:_3/ J Existing Facility New Facility Rated By: d. Date: 1— Reviewed (Train. & Cert-) Reg. Office 2- 2 Reviewed' (Train. & Cert.) Central O#tic . ORC_ �a.,-r.� _� % Grade 7-- ITEM POINTS ITEM POINT (1) Industrial Pretreatment Units and/or (4) PRIMARY TREATMENT UNITS Industrial Pretreatment Program / (see -definition No. 33) 19 (a) Septic Tank (see derinition no. 43) .............. (b) Imholf Tank .................................. 2 S (2) JQFSlQN FLOW OF PLANT IN GPO (c) Primary Clarifiers ............................ S (not applicable to non -contaminated cooling (d) Settling Ponds or Settling Tanks for Inorganic waters, sludge handling facilities for water Non -toxic Materials (sludge handling facilities purification plants, totally closed cycle for water purilicalion plants, sand, gravel, systems (del. No. 11), and facilities stone, and other mining operations except consisting only of Item (4) (d) or Items (4) (d) recreational activities such as gem or gold and (11) (d)) mining) .. .. ....................... 2 0 — 20,000 ................... ► ...... 1 (5) SECONDARY TREATMENT UNITS 20,001 — 50,000 .................. . . . ..... 2 (a) Carbonaceous Stage 50.001 — 100.000 .......................... I (i)Aeration - High Purity Oxygen System ..... 20 100,001 — 250,000 .......................... Diffused Air System ........... 250,001 — 500,000................. ..... 5 Mechanical Air System (fixed. $00.001--1.000,000 .......................... 8 floating or rotor) . ... ....... i 1,000,001 2.000,000 ......... ............ .. 10 Separate Sludge Reaeration ..... 3 2,000,001 (and up) - rate 1 point additional for each (it) Trickling Filter 200,000 gpd capacity up to a High Rate ................... 7 maximum of 30 Standard Rate ............... 5 Packed Tower............... 5 (Ili) Biological Aerated Filter or Aerated Design Flow (gpd) Biological Filter ...................... 10 (Iv) Aerated Lagoons ..................... . 10 (v) Rotating Biological Contactors .......... 10 (3) PRELIMINARY UNITS (see deru,ition no. 32) (a) Bar Screens 4 (vi) Sand Filters- intermittent biological .. 2 ................................ recirculating biological .-.... 3 or (b) Mechanical Screens, Stalic Screens or (v7 Stabilization lagoons.... . + +........ -�`- (viii)Clarifier .............................. Comminuting Devices ........................ (ix) Single stage system for combined (c) Grit Removal ............................... carbonaceous removal of SOD and or (d) Mechanical or Aerated Grit Removal ........... 2 nitrogenous removal by nitrification (see del. No. 12) (Points for this item (e) Flow Meuuring Device ....................... 1 have to be in addition to items (5) (a) of (I} instrumented Flow Measurement , , , , , , , , , , , , , , D. (1) through (S) (a) (vs+) ................. (x) Nutrient additions to enhance 900 e (g) Preaeration................................ 2 removal ..... ... ..... .. .. ... 5 (h) Influent Flow Equa5=lion 2 (xi) Biological Culture ('Super Bugs') addition 5 ................... _ 47 Grease or 00 Separators - Gravity .......... 2 to enhance organic compound removal . - .. . Mechanical .......... 3 Dissolved Air Flotation. d UjPrecworination .............................. 5 A Nitrogenous Stage W Aeration - High Purity Oxygen System ..... 20 Diffused Air System ........... 10 Mechanical Air System (fixed, floating, or rotor) . ... ..... 8 Separate Sludge Reaeratibn ..... 3 (i) Trickling Filler - High Rate .............. 7 Standard Rate ............ 5 Packed Tower............ 5 (iii) Biological Aerated Filler or Aerated Biological Filler ......................... 10 Civ) Rotating Biological Contactors ............ 1 D (v) Sand Filler - intermittent biological ........ 2 recirculating biological ........ 3 (vi) Clarifier ........................... . .... 5 (6) TERTIARY OR ADVANCED TREATMENT UNIT (a) Activated Carbons Beds - without carbon regeneration .................. 5 with carbon regeneration .. .................. 15 (b) Powdered or Granular Activated Carbon Feed - without carbon regeneration ................. 5 with carbon regeneration ................... 15 (c) Air Stripping ............................. 5 (d) Denitrification Process (separate process) ..... 10 (e) Elecurdialysis ........ - ............:....... 5 (9 Foam Separation ............................. 5 (g) Ion Exchange ................................ 5 (h) Land Application of Treated Effluent (see definition no. 22b) (not applicable for sand, gravel, stone and other similar mining operations) . ,Z47 on agriculturally managed sites (See del - No. ...... ................... 10 (iij by high rate infiltration on non -agriculturally managed sites (includes rotary distributors and similar fixed nozzle systems) ........... 4 (fri) by subsurface disposal (includes low pressure pipe systems and gravity systems except at plants consisting of septic tank and,nitrifica- tlon Ernes only) ............................. 4 () W=screens ...................... ...... •Biological 5 (j) Phosphorus Removal by Proses (See def. No. 26) ........ ....... . ......... 20 (k) Polishing Ponds - without aeration ....... 2 with aeration .......... 5 (1) Post Aeration - cascade .............. 0 diffused or mechanical ... 5 (m) Reverse Osmosis ............................... 5 (n) Sand or Mixed -Media Fillers -low rate ........... 2 • hgh rate .......... 5 (o) Treatment processes for removal of metal or cyanide.................................... 15 (p) Treatment processes for removal of toxic materials other than metal or cyanide ......... 15. (7) SLUDGE TREATMENT (a) Sludge Digestion Tank- Heated ............... 1 Aerobic . .. » ......... Unheated ............. 3 (b) Sludge Stabll4ation (chemical or thermal) ....... 5 (c) Sludge Drying Beds - Gravity ... ..... . ..... 2 Vacuum Assisted ....... 5 (d) Sludge Ekdriation ............................. 5 (a) Sludg• Conditioner (chemical w thermal) ........ 5 Sludge Thickener (gravity) .. .................. S ! Dissolved Air Flotation Uni (not applicable to a unit rates as (3) (i) ......... 6 (h) Sludge Gas Utilization (nduding gas storage) .... 2 (t) Sludge Holding Tank - Aerated ................ 5 Non -aerated ............ 2 G) Sludge Incinerator - (not including activated Carbon regeneration) ..... 10 (k) Vacuum Filter, Centrifuge or Filter Press or other similar dewalering devices ................. . .. 10 (8) SLUDGE DISPOSAL (including incinerated ash) (a)Lagoons. ............................. (b) Land Application (surface and subsurface) (see definition 22a) -where the facility holds the land app. permit ... 0 -by contracting to a land application operator who holds the land application permit ........... . ... 2 -land application of sludge by a contractor who does not hold the permit for the wastewater treatment facility where the sludge is generated ......... 10 (c) Landfilled (burial) ............................. 5 (9) DISINFECTION (a) Chlorination .............................. l 141 (b) Dechlorination ........................ (c) Ozone ... ........................... 5 (d) Radiation .............. ... ... 5 (10) CHEMICAL ADDITION SYSTEM (S) (See definition No. 9) (not applicable to chemical additions rated as item (3) 0). (5) (a) (xi). (6) (a). (6) (b). (7) (b). (7) (e}, (9) (a), (9) (b), or (9) (c) 5 points each: List: 5 5 5 (11) MISCELLANEOUS UNITS (a) Molding Ponds, Hokfing Tanks or Settling Ponds for Organic or Toxic Materials including wastes from mining operations containing nitrogen and/or phosphorous compounds in amounts signif'rcanity greater than is common for domestic wastewater .......... 4 (b) Effluent Flow Equalization (not applicable to storage basins which are inherent in land application systems). 2 (c) Stage Discharge (not applicable to storage basins (d) inherent in land application systems ....................................... Pumps. -- -- 5� —.& (e) Stand -By Power Supply---__--_...._-. Thermal Pollution Control Device......--.....--........_....._... (1) TOTAL POINTS CLASSIFICATION Class 1 5 - 25 Points toss It. _ 26- 50 Points s u. 51- 65 Points _ 66- Up Points Facilities having a rating of one through four points, inclusive. do not require a certified operator. Classification of all other facilities requires a comparable grade operator in responsible charge. Facilities having an activated sludge process will be assigned a minimum classification of Class IL Facilities having treatment processes for the removal of metal or cyanide will be assigned a minimum classification of Class 11. Facilities having treatment processes for the biological removal of phosphorus will be assigned a minimum classification of Class` 111.