City of Columbus. Legislation Report File Number:

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1 30-day City of Columbus Legislation Report File Number: Office of City Clerk 90 West Broad Street Columbus OH columbuscitycouncil.org File ID: Type: Ordinance Status: Passed Version: File Name: 11/10/ *Committee: Rules & Reference Committee Chapter 1145, Sewer Use Regulations File Created: Final Action: 12/16/2015 Auditor Cert #: Auditor: When assigned an Auditor Certificate Number I, the City Auditor, hereby certify that there is in the treasury, or anticipate to come into the treasury, and not appropriated for any other purpose, the amount of money specified hereon, to pay the within Ordinance. Contact Name/No.: Susan Ashbrook/ Floor Action (Clerk s Office Only) Mayor's Action Council Action Mayor Date Date Passed/ Adopted President of Council Veto Date City Clerk Title: To amend and enact various sections of Chapter 1145, Sewer Use Regulations, of the Columbus City Code, in order to establish the City s inflow and infiltration reduction program, and to authorize the Director of Public Utilities to designate those areas served by the City s sanitary sewer system where the program will be implemented as well as to prioritize those areas so designated for implementation. Sponsors: Zach M. Klein City of Columbus Page 1 of 5 Printed on 12/18/2015

2 City of Columbus Legislation Report File Number: Office of City Clerk 90 West Broad Street Columbus OH columbuscitycouncil.org Attachments: ORD Ordaining Language, Infiltration_Inflow_Impacts Approval History Version Date Approver Action 1 11/11/2015 Jonathan Lee Approved 1 11/12/2015 Greg Davies Approved 1 11/12/2015 Aileen Heiser Approved 1 11/13/2015 John Laughman Approved 1 11/13/2015 Adam Robins Approved 1 11/16/2015 Paul Rakosky Approved 1 11/16/2015 Auditor Reviewer Approved Notes HJD/bam 1 11/16/2015 AUDITOR APPROVER Approved Notes Hugh J Dorrian/rlm 1 11/17/2015 ATTORNEY APPROVER Approved Notes wsb History of Legislative File Ver. Acting Body: Date: Action: Sent To: Due Date: Return Result: Date: 1 Columbus City Council 12/07/2015 Read for the First Time 1 Columbus City Council 12/14/2015 Approved Pass City of Columbus Page 1 of 5 Printed on 12/18/2015

3 City of Columbus Legislation Report File Number: Office of City Clerk 90 West Broad Street Columbus OH columbuscitycouncil.org 1 COUNCIL PRESIDENT 12/14/2015 Approved 1 COUNCIL PRESIDENT 12/14/2015 Signed 1 MAYOR 12/15/2015 Signed 1 CITY CLERK 12/16/2015 Attest EBOCO: Following review and approval, when required, the Equal Business Opportunity Commission Office certifies compliance with Title 39 as of date listed. City Attorney: Following review and approval, when required, this ordinance has been reviewed by the City Attorney's Office as to its form and legality only. Explanation This ordinance amends and enacts sections of the Columbus City Code Chapter 1145, Sewer Use Regulations, to establish the City s inflow and infiltration reduction program, and to authorize the Director of Public Utilities to designate those areas served by the City s sanitary sewer system where the program will be implemented as well as to prioritize areas so designated for implementation. Fiscal Impact: There is no direct fiscal impact from this legislation. Implementation of the inflow and infiltration program authorized by this legislation will be authorized by additional legislation which will appropriate necessary funds. It is estimated that the program will cost approximately $1.7 billion over the next twenty years. Title To amend and enact various sections of Chapter 1145, Sewer Use Regulations, of the Columbus City Code, in order to establish the City s inflow and infiltration reduction program, and to authorize the Director of Public Utilities to designate those areas served by the City s sanitary sewer system where the program will be implemented as well as to prioritize those areas so designated for implementation. Body WHEREAS, under the authority provided in the Ohio Constitution, the Ohio Revised Code and its Charter, the City of Columbus owns and operates a separate sanitary sewer system (the Sanitary System or System ) that provides sanitary wastewater collection and treatment services for the City and its inhabitants, and also for certain adjacent areas and the inhabitants in those areas. The City s Sanitary System is designed to convey domestic, commercial and industrial wastewater to one of the City of Columbus Page 1 of 5 Printed on 12/18/2015

4 City of Columbus Legislation Report File Number: Office of City Clerk 90 West Broad Street Columbus OH columbuscitycouncil.org City s wastewater treatment plants for treatment and ultimate discharge; and WHEREAS, the Sanitary System is distinct from the City s municipal storm sewer system, which is designed solely to transport rain runoff from streets and other impervious areas directly to streams and rivers; and WHEREAS, during periods of heavy precipitation, rain water can enter into the Sanitary System, causing it to become overwhelmed; this is known as inflow and infiltration or I/I. Significant I/I causes the Sanitary System to overflow into streams and rivers (which events are known as sanitary sewer overflows or SSOs ) and also causes the System to backup into basements (known as water in basements or WIBs ); and WHEREAS, the State of Ohio, in 2002, filed suit against the City for these SSO events, alleging that they violate R.C Chapter 6111, the State s water pollution control law. The City ultimately entered into a Consent Order with the State requiring the City to prepare and implement a System Evaluation and Capacity Assurance Plan ( SECAP ) to eliminate SSOs and WIBs; and WHEREAS, the City submitted its SECAP to Ohio EPA in 2005, as part of its Wet Weather Management Plan; and WHEREAS, Ohio EPA subsequently approved the City s SECAP, which calls for construction of two large, deep tunnels to store and ultimately convey all of the flow from the System s collection system to one of the City s wastewater treatment plants for treatment prior to discharge. These tunnels do not address the excessive I/I in the System; they merely capture the excessive I/I for storage, conveyance and treatment. These tunnels are currently estimated to cost $2.5 billion; and WHEREAS, in 2012, the City obtained permission from Ohio EPA to delay construction of the tunnels in order to re-evaluate its approach to eliminating SSOs and WIBs; and WHEREAS, the City has determined that it can achieve the same SSO and WIB elimination by reducing excessive I/I from the system, thus eliminating most of the tunnels. The revised plan is currently estimated to cost $1.7 Billion over the next twenty years, which is far less than the original SECAP plan; and WHEREAS, the City has determined that the primary source of excessive I/I in the System is residential areas. Specifically, the majority of the I/I is from leaking and/or deteriorated private sanitary laterals as well as downspouts and foundation drains which are connected to the System; and WHEREAS, the City has also determined that the best method of addressing the contribution from these sources is to rehabilitate or replace these private sanitary laterals as well as to disconnect and/or redirect downspouts away from the perimeter of the house. In addition, the City has determined that a voluntary sump pump program for these same houses will further reduce I/I. This I/I Reduction Program is known as Blueprint Columbus ; and WHEREAS, SSOs and WIBs allow sewage to escape from the System and potentially allow human contact with the raw sewage. Raw sewage contains many pathogens which are associated with illnesses; and WHEREAS, this Council has determined that excessive I/I which results in SSOs and WIBs are a City of Columbus Page 1 of 5 Printed on 12/18/2015

5 City of Columbus Legislation Report File Number: Office of City Clerk 90 West Broad Street Columbus OH columbuscitycouncil.org potential threat to public health, safety and the environment and other natural resources and thereby constitute public nuisances; and WHEREAS, Council has determined that it is necessary and appropriate and in the best interest of the City and its inhabitants to provide for the abatement of the nuisance conditions caused by excessive I/I by rehabilitation and/or replacement of private sanitary laterals and for the disconnection and/ or redirecting of water from downspouts away from the System for the public purposes of addressing conditions deleterious to the public health and safety and the environment and other natural resources, to provide for and enable the environmentally safe and productive use of private lands in the City, abating the public nuisances those conditions present, assisting the City in complying with its consent order with Ohio EPA requirements and protecting the System and promoting its effective and efficient operation; and WHEREAS, this Council has determined to authorize the Director of Public Utilities to designate areas of the City to implement the I/I Reduction Program, and to prioritize those areas; WHEREAS, the Department of Public Utilities is requesting City Council to amend and enact sections of Chapter 1145, Sewer Use Regulations" in order to establish the City s inflow and infiltration reduction program at the earliest time available thereby preserving the City's public health, peace, safety, and welfare; NOW, THEREFORE BE IT ORDAINED BY THE COUNCIL OF THE CITY OF COLUMBUS: [see attachment] City of Columbus Page 1 of 5 Printed on 12/18/2015

6 SECTION 1. That the existing Section of the Columbus City Codes is hereby amended to read as follows: Definitions. Whenever used in this Chapter 1145, the meaning of the following words and terms shall be as defined in this section: Amalgam or mercury amalgam: Any of various alloys of mercury with other metals, especially an alloy of mercury and silver used in dental fillings Approved laboratory procedures: The measurements, tests, and analyses of characteristics of water and wastes in accordance with analytical Federal guidelines as established in Title 40, Code of Federal Regulations (CFR) Part 136; or when none exists, as required by, or approved by, the regional Administrator of the United States Environmental Protection Agency; or when none exists, by the State of Ohio, or the Director Authorized or duly authorized representative of the user: (A) (B) (C) (D) If the user is a corporation: (1) The president, secretary, treasurer, or a vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy or decision-making functions for the corporation; or (2) The manager of one (1) or more manufacturing, production, or operating facilities, provided the manager is authorized to make management decisions that govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiate and direct other comprehensive measures to assure long-term environmental compliance with environmental laws and regulations; can ensure that the necessary systems are established or actions taken to gather complete and accurate information for individual wastewater discharge permit requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures. If the user is a partnership or sole proprietorship: a general partner or proprietor, respectively. If the user is a federal, state, or local governmental facility: a director or highest official appointed or designated to oversee the operation and performance of the activities of the government facility, or their designee. The individuals described in paragraphs A through C, above, may designate a duly authorized representative if the authorization is in writing, the authorization specifies the individual or position responsible for the overall operation of the facility from which the discharge originates or having overall responsibility for environmental matters for the company, and the written authorization is submitted to the City of Columbus.

7 Best management practices (BMPs): Schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to implement the prohibitions listed in Rule of the Ohio Administrative Code. BMPs also include treatment requirements, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw materials storage Biodegradable: Any material capable of being decomposed by biological agents especially bacteria and is easily broken down by biologic processes to nontoxic substances that exert an acceptable oxygen demand or nondeleterious effect on the receiving environment BOD or Biochemical oxygen demand: The quantity of oxygen utilized in the biochemical oxidation of organic and inorganic matter in five (5) days at twenty (20) degrees C in accordance with an approved test procedure Bypass: The intentional diversion of wastestreams from any portion of a user's treatment facility Categorical industrial user: An industrial user subject to a categorical pretreatment standard or categorical standard Categorical pretreatment standard: Any regulation containing pollutant discharge limits enacted by USEPA in accordance with section 307(b) and (c) of the Clean Water Act (33 U.S.C. Section 1317(b) and (c)) which applies to industrial users. This term includes prohibitive discharge limits established pursuant to 40 CFR Part 403. Centralized waste treatment facility: means a facility that treats or recovers hazardous or non-hazardous industrial metalbearing waste, oily waste, and organic-bearing waste from off-site CFR: Code of Federal Regulations City: The City of Columbus, Ohio City of Columbus Construction and Material Specifications: A manual compiled by the department of public service, which outlines specifications for construction of public works for the City of Columbus Clean Water Act or CWA: Federal Water Pollution Control Act, also known as the Clean Water Act, as amended 33 U.S.C. Sec et seq., 86 Statutes 816, Public Law COD or Chemical oxygen demand: A quantitative measure of the oxygen equivalent of the organic matter present in a sample that is susceptible to oxidation by a strong chemical oxidant in accordance with an approved test procedure Combined sewer: A sewer, which was designed to carry sanitary wastewater and stormwater to the POTW or waters of the state Combined wastewater: Wastewater including any combination of sanitary wastewater and stormwater carried to the POTW treatment plants by a sewer.

8 Composite sample: A combination of individual samples representative of water or wastewater taken at preselected intervals to minimize the effect of the variability of the individual sample. Composite samples may be collected as either: (A) (B) Flow proportional composite samples-collected either as a constant sample volume at time intervals proportional to stream flow, or collected by increasing the volume of each sample as the flow increases while maintaining a constant time interval between the samples. Time proportional composite samples-composed of discrete samples collected in one (1) container at constant time intervals providing representative samples irrespective of flow Cooling water: Water used for contact and noncontact cooling, including, but not limited to, water used for equipment cooling, evaporative cooling tower makeup, or reduction of effluent heat content Daily maximum: The arithmetic average of all effluent samples for a pollutant collected during a calendar day Daily maximum limit: The maximum allowable discharge limit of a pollutant during a calendar day. Where daily maximum limits are expressed in units of mass, the daily discharge is the total mass discharged over the course of the day. Where daily maximum limits are expressed in terms of concentration, the daily discharge is the arithmetic average measurement of the pollutant concentration derived from all measurements taken that day Day: Calendar day Decontamination wastewater: Wastewater generated during the process of neutralizing contaminants that have accumulated on personnel or equipment due to a nuclear, biological or chemical emergency Deleterious substance: Any material which may be harmful to the POTW, the POTW treatment plant processes, the health and safety of POTW workers, and the POTW effluents or residual products Department: The Department of Public Utilities, City of Columbus, Ohio Director: The Director of the Department of Public Utilities, City of Columbus, or designee Discharge: The introduction of liquids or wastes into the sewer system DOSD: Division of Sewerage and Drainage Domestic origin waste: Waste materials that originate solely from domestic wastewater which are removed from sewage disposal systems such as septic tanks, aeration systems, portable toilets, and sewage holding tanks Domestic wastewater: Wastewater derived solely from household sources, business buildings, and institutions, exclusive of any industrial wastewater.

9 Downspout: A vertical structure used to drain rain collected in gutters from a roof to the ground Existing source: Any source of discharge that is not a "new source" Extra-strength: Any discharge to the POTW that has strength characteristics, which exceed two hundred fifty (250) mg/l of BOD 5, four hundred fifty (450) mg/l of COD, three hundred (300) mg/l of Total Suspended Solids (TSS), and forty (40) mg/l of Total Kjeldahl Nitrogen (TKN) Foundation drain: An exterior A drainage system that allows water to flow away from for the lowest portion of a structure, typically a basement, without using pumps or electricity Fats, oils and grease or FOG: a semi-solid, viscous liquid organic polar compound derived from petroleum, animal or plant sources that contain multiple carbon chain triglyceride molecules. These substances are detectable and measurable using analytical test procedures established in 40 Code of Federal Regulations (CFR) Part 136, as may be amended Flammable: Any substance that has a flashpoint of less than or equal to one hundred forty (140) degrees Fahrenheit FSE or food service establishment: A commercial facility engaged in preparing or serving food for consumption by the public, such as but not limited to: restaurant, commercial kitchen, cafeterias, nightclubs, delicatessen, meat cutting-preparation, bakeries, bagel shops, grocery stores, caterer, hotel, school, hospital, correctional facility or care institution Grab sample: A sample that is taken from a waste stream without regard to the flow in the waste stream and over a period of time not to exceed fifteen (15) minutes Grease interceptor: A tank that serves one (1) or more fixtures and is remotely located. Such grease interceptors include, but are not limited to, tanks that capture wastewater from dishwashers, garbage grinders, floor drains, pot and pan sinks and trenches. A grease interceptor is an outside, underground, tank that reduces the amount of FOG in wastewater prior to discharging into the POTW Grease trap: A small indoor device designed to retain grease Hazardous waste: A waste, as defined by Ohio Administrative Code Rule Household sources: Any source of wastewater limited to sanitary wastes from single and multiple family residences, hotels, motels, crew quarters, camp grounds, picnic grounds, or day use recreation areas. Household sources shall not include any industrial or commercial process wastewater.

10 Illicit discharge: Discharge of any pollutant to the stormwater drainage system that occurs or may occur unless the discharge is authorized under a discharge permit issued by the Ohio EPA Incompatible: Any wastewater or other substance that is deleterious or which degrades the quality of the POTW effluent or its sludges and residual products Indirect discharge or discharge: The introduction of pollutants into the POTW from any nondomestic source Industrial cost recovery: The system for recovery of the industrial portion of the United States Environmental Protection Agency Project Grant Funds, as required by CFR Title 40 or subsequent revisions Industrial user or IU: Any user who discharges, or permits the discharge of industrial wastewater to the city's POTW Industrial wastewater: Any combination of liquid and watercarried wastes, discharged from any industrial or commercial establishment, and resulting from any trade or process carried on in that establishment, including the wastewater from pretreatment facilities and polluted cooling water. Any wastewater from nondomestic sources Infiltration: Stormwater and groundwater that enters a sanitary sewer system through such means as, but not limited to, defective pipes, pipe joints, connections, or manhole walls. Infiltration does not include, and is distinguished from, inflow Inflow: Stormwater and groundwater that enters a sanitary sewer system, from such sources as, but not limited to, roof leaders; cellar, yard and area drains; foundation drains; cooling water discharges; drains from springs and swampy areas; manhole covers; cross connections from storm sewers; combined sewers; catch basins; storm waters; surface runoff; street wash-waters; or drainage. Inflow does not include, and is distinguished from, infiltration Inflow and Infiltration or I/I: The total quantity of water from both infiltration and inflow entering a sanitary sewer system without distinguishing the source Instantaneous limit: The maximum concentration of a pollutant allowed to be discharged at any time, determined from the analysis of any discrete or composited sample collected, independent of the industrial flow rate and the duration of the sampling event Interference: A discharge which, alone or in conjunction with the discharge or discharges from other sources, either: (A) (B) Inhibits or disrupts the POTW, its treatment processes or operations, or its sludge processes, use or disposal. Is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation) or of the

11 prevention of sewage sludge use or disposal in compliance with state and federal statutory provisions and regulations or permits issued thereunder Local limit: Specific discharge limits developed and enforced by the City of Columbus upon industrial or commercial facilities or users to implement the general and specific discharge prohibitions pursuant to Section of this chapter Medical waste: Isolation wastes, infectious agents, human blood and blood products, pathological wastes, hypodermic needles, disposable scalpels, and other sharp implements used in medical care, body parts, contaminated bedding, surgical wastes, potentially contaminated laboratory wastes, and dialysis wastes Monthly average: The sum of all "daily discharges" measured during a calendar month by dividing by the number of "daily discharges" measured during that month Monthly average limit: The highest allowable average of "daily discharges" over a calendar month, calculated as the sum of all "daily discharges" measured during a calendar month divided by the number of "daily discharges" measured during that month mg/l: Milligrams per liter Monitoring facility: A site accessible to the city for the collection of samples, flow data, or other parameters representative of the user's discharge to the POTW MS4: an acronym for "municipal separate storm sewer system and is used to refer to either a large or medium municipally-owned separate storm conveyance system Natural outlet: Any outlet for discharge of stormwater into a watercourse, pond, ditch, lake, or other body of surface water New source: (A) Any building, structure, facility or installation from which there is, or may be, a discharge of pollutants, the construction of which commenced after the publication of proposed Categorical Pretreatment Standards under Section 307(c) of the Clean Water Act (33 U.S.C. Section 1317(c)) which will be applicable to such source, if such standards are thereafter enacted in accordance with that section, provided that: (1) The building, structure, facility or installation is constructed at a site which no other source is located; or (2) The building, structure, facility or installation totally replaces the process or production equipment that causes the discharge of pollutants at an existing source; or (3) The production or wastewater generating processes of the building, structure, facility or installation are substantially independent of an existing source at the same site. In determining whether the above criteria are substantially independent, factors such as the extent to which the new facility is integrated with the existing plant, and the extent to which the new facility is engaged in the same general type of activity as the existing source, shall be considered. (B)

12 Construction on a site at which an existing source is located results in a modification rather than a new source if the construction does not create a new building structure, facility, or installation meeting the criteria of Section (A)(2) or (3) above but otherwise alters, replaces, or adds to existing process or production equipment. (C) Construction of a new source as defined under this paragraph has commenced if the owner or operator has: (1) Begun, or caused to begin, as part of a continuous onsite construction program (a) Any placement, assembly, or installation of facilities or equipment; or (b) Significant site preparation work including clearing, excavation, or removal of existing buildings, structures, or facilities which is necessary for the placement, assembly, or installation of new source facilities or equipment; or (2) Entered into a binding contractual obligation for the purchase of facilities or equipment which are intended to be used in its operation within a reasonable time. Options to purchase or contracts which can be terminated or modified without substantial loss, and contracts for feasibility, engineering, and design studies do not constitute a contractual obligation under this paragraph Noncompliance: Any violation of this chapter Nondomestic user: Any user, which discharges wastewater other than from household sources NPDES: National Pollutant Discharge Elimination System NPDES permit: A permit issued to the city pursuant to Section 402 of the Clean Water Act Oil: Any vegetable, mineral, animal, or synthetic substance which are generally slippery, combustible, viscous, liquid or liquefiable, soluble in various organic solvents or water Operator: The person responsible for the overall operation of a facility ORC: Ohio Revised Code Organic: Any compound containing carbon in any form other than carbonate Owner: The person who owns a facility, or any part of a facility.

13 Pass-through: A discharge which exits the POTW into the waters of the United States in quantities or concentrations which, alone, or in conjunction with a discharge or discharges from other sources, is a cause of a violation of any requirement of the POTWs NPDES permit (including an increase in the magnitude or duration of a violation) Person: Any individual, partnership, copartnership, firm, company, corporation, association, joint stock company, trust, estate, government entity, or any other legal entity; or their legal representatives, agents or assigns. This definition includes all federal, state, and local governmental entities ph: The logarithm (to the base 10) of the reciprocal of the hydrogen ion concentration of a solution expressed in gram atoms per liter of solution Pollution: The man-made or man-induced alteration of the chemical, physical, biological, or radiological integrity of water POTW or publicly owned treatment works: A treatment works owned by the City of Columbus as defined by Section 212 of the Clean Water Act (33 U.S.C Section 1292). This definition includes any devices and systems used in the collection, storage, treatment, recycling and reclamation of sewage or industrial wastes of a liquid nature, including sewers, pipes and other conveyances that convey wastewater to a POTW treatment plant POTW treatment plant: That portion of the POTW which is designed to provide treatment (including recycling and reclamation) of municipal sewage and industrial waste Pretreatment: The reduction of the amount of pollutants, the elimination of pollutants, or the alteration of the nature of pollutant properties in wastewater to a less harmful state prior to, or in lieu of, discharging such pollutants into a POTW. This reduction or alteration can be obtained by physical, chemical, or biological processes; by process changes; or by other means, except by diluting the concentration of the pollutants unless allowed by an applicable pretreatment standard Pretreatment requirements: Any substantive or procedural requirement related to pretreatment imposed on a user, other than a pretreatment standard Pretreatment standards or standards: Shall include prohibited discharge standards, categorical pretreatment standards, and local limits as defined herein Private Sanitary Lateral: The pipe carrying wastewater from a building to the sanitary sewer Prohibited discharge standards or prohibited discharges: Absolute prohibitions against the discharge of certain substances; these prohibitions appear in Section through of this chapter, as well as, regulations adopted by the director Public sewer: Any sewer owned by the city, suburb, or entity contracting with the city, including storm, sanitary, or combined sewers.

14 Radioactive: The property of a material providing spontaneous decay or disintegration of an unstable, atomic nucleus, accompanied by the emission of radiation RCRA or Resource Conservation and Recovery Act: The Solid Waste Disposal Act (SWDA), as amended by the Resource Conservation and Recovery Act of 1976 and amendments to the Act, 42 U.S.C. Sec et seq Rehabilitate: To repair an existing sewer line Replace: To put something new in the place of Surface runoff: The flow of water, from rain, snowmelt, or other sources, over land SDWA: Safe Drinking Water Act, as amended, 42 U.S.C. Sec. 300f et seq Sanitary sewer: A sewer which by design is intended to carry sanitary wastewater or industrial wastes into which storm, surface and ground waters are not intentionally admitted Sanitary Sewer Overflow or SSO: An overflow, spill or release of wastewater from the separate sanitary sewer system into the environment Sanitary wastewater: The combination of liquid and watercarried wastes discharged from toilet and other sanitary plumbing facilities of dwellings, office buildings, industrial plants or institutions Septic tank waste: Any sewage from holding tanks such as vessels, chemical toilets, campers, trailers, and septic tanks Sewage: Human excrement and gray water (household showers, dishwashing operations, etc.) Sewer collection system, sewer system or collection system: All of the facilities required to transport stormwater, sanitary wastewater or combined wastewater from the source to the POTW treatment plant or waters of the state Sewer service charge: The total monetary amount billable to a user for the provision of wastewater treatment and related activities Significant industrial user or SIU: Except as provided in paragraphs (C) and (D) of this section, a significant industrial user is: (A) (B) An industrial user subject to categorical pretreatment standards; or An industrial user that: (1) Discharges an average of twenty-five thousand (25,000) gallons per day (gpd) or more of process wastewater to the POTW (excluding sanitary, noncontact cooling and boiler blowdown wastewater);

15 (2) Contributes a process wastestream which makes up five (5) percent or more of the average dry weather hydraulic or organic capacity of the POTW treatment plant; or (3) Is designated as such by the City of Columbus on the basis that it has a reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement. Non-significant categorical industrial user (C) The City of Columbus may determine that an industrial user subject to categorical pretreatment standards is a non-significant categorical industrial user on a finding that the industrial user never discharges more than one hundred (100) gpd of total categorical wastewater (excluding sanitary, non-contact cooling and boiler blowdown wastewater, unless specifically included in the categorical pretreatment standard) and the following conditions are met: (1) The industrial user, prior to the City of Columbus' finding, has consistently complied with all applicable categorical pretreatment standards and requirements; (2) The industrial user annually submits the certification statement required in Section (B), together with any additional information necessary to support the certification statement; and (3) The industrial user never discharges any untreated concentrated wastewater. (4) The industrial user is not located upstream of a combined sewer overflow or a sanitary sewer overflow, unless the following conditions are met: (a) The industrial user does not discharge wastewater regulated by categorical pretreatment standards at any time; or (b) The industrial user has not been in significant noncompliance, as defined in OAC (C)(2)(h) for any time in the past two (2) years. (D) Upon a finding that a user meeting the criteria in Subsection (B) under the definition of significant industrial user has no reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement, the City of Columbus may at any time, on its own initiative or in response to a petition received from an industrial user, and in accordance with procedures in 40 CFR 403.8(f)(6), determine that such user should not be considered a significant industrial user Slug load or slug discharge: Any discharge at a flow rate or concentration, which could cause a violation of the prohibited discharge standards in Section through of this chapter, as well as, regulations adopted by the director. A slug discharge is any discharge of a non-routine, episodic nature, including but not limited to an accidental spill or a non-customary batch discharge, which has the reasonable potential to cause interference or pass through, or in any other way violate the POTW's regulations, local limits or permit conditions Standard: Any limit or prohibition on discharges as provided for by this chapter SIC or Standard industrial classification: A classification pursuant to the most current edition of the Federal Standard Industrial Classification Manual and North American Industrial Classification System, as published by the Executive Office of the President, Office of Management and Budget.

16 Standard methods: Standard Methods for the Examination of Water and Wastewater as published by the American Public Health Association, the American Water Works Association, and the Water Environment Federation. References are to the current edition unless otherwise indicated Standard strength: Wastewater of strength equivalent to domestic wastewater, i.e. having BOD 5 of two hundred fifty (250) mg/l or less; COD of four hundred fifty (450) mg/l or less; TSS of three hundred (300) mg/l or less; and TKN of forty (40) mg/l or less S.U.: Standard units State: State of Ohio Storm water: Any flow occurring during or following any form of natural precipitation, and resulting from such precipitation, including snowmelt Storm Water Pollution Prevention Plan (SWP3) or (SWPPP): The plan required by the Ohio EPA for compliance with its general or individual NPDES permit Storm sewer: Unless otherwise indicated, refers to a municipal separate storm sewer Stream: A surface watercourse having a channel with a well defined bed and bank, either natural or artificial, which confines and conducts continuous or periodic flowing water Total dissolved solids (TDS): The sum of all dissolved solids (volatile and non-volatile) in water or wastewater Total Kjeldahl Nitrogen (TKN): Is the sum of nitrate (NO 3), nitrite (NO 2), organic nitrogen and ammonia (all expressed as N). Note: for laboratory analysis purposes, Total Kjeldahl Nitrogen (TKN) is a test performed that is made up of both organic nitrogen and ammonia Total non-filterable residue (TNFR): Same as Total Suspended Solids (TSS) Total Organic Carbon (TOC): The measure of the concentration of covalently bonded carbon, which is combustible to carbon dioxide. It is not to be confused with elemental carbon, dissolved carbon dioxide, inorganic carbonates or bicarbonates Total silver process wastewater: The sum of all aqueous solutions used in silver imaging processes, including photography film developers, fixers, bleachfix, stabilizers, low flow washes, rinse waters, other washes and all similar solutions Total suspended solids (TSS): The total suspended matter that either floats on the surface of, or is in suspension within, water, wastewater, or other liquids, and that is removable by laboratory filtering as prescribed by Standard Methods (same as TNFR) Toxic: Any pollutant, or combination of pollutants, listed as toxic in regulations enacted by the Administrator of the USEPA, or under the provision of the Clean Water Act, Section 307(a) (33 U.S.C. Section 1317(a)) or other Acts Trucked waste disposal site or TWDS: The location(s) designated by the director for receiving trucked wastes into the POTW Trucked wastes: Any materials, usually liquid, such as, but not limited to, wastes from septic tanks, aeration systems, portable toilets, sewerage holding tanks, and industrial processes which are collected at the source by tank truck for disposal elsewhere ug/l: Micrograms per liter USC: United States Code USEPA: United States Environmental Protection Agency Used oil: Any oil that has been used, and, as a result of such use, contaminated with chemical or physical impurities.

17 User: Any person who contributes, causes, or permits the contribution of wastewater or stormwater into the city's sewer system or POTW Wastewater: The combination of the liquid and water-carried wastes and sewage from residences, commercial buildings, industrial plants and institutions including polluted cooling water, whether treated or untreated Water in Basement (WIB) Event: Wastewater backups into buildings that are caused by flow conditions in a sewer main due to a rain event. Wet Weather Water in Basement (WIB) events do not include basement backups that occur in dry weather Waters of the state: All streams, lakes, ponds, marshes, watercourses, waterways, wells, springs, irrigation systems, drainage systems, and other bodies or accumulations of water, surface and underground, natural or artificial, regardless of the depth of the strata in which underground water is located, that are situated wholly or partly within, or border upon this state, or are within its jurisdiction, except those private waters that do not combine or effect a junction with natural surface or underground waters. SECTION 2. That existing Section of the Columbus City Codes is hereby repealed. SECTION 3. That the Columbus City Codes are hereby revised and supplemented with the enactment of Sections , , and to read as follows: Authority of the Director to Designate Areas for Implementation of Inflow and Infiltration Reduction Program (A) The director may designate areas within the sanitary sewer system where excessive I/I is causing SSOs and/or WIB events. The areas so designated shall be subject to the I/I reduction program on a schedule to be determined by the director. The director may designate more than one area at a time, and if so, the designation may include a prioritization of the areas for implementation of the I/I reduction program. The prioritization may be made on the basis of the number, frequency and duration of the SSOs and WIB events, the likelihood of human exposure and the priority, if any, assigned by Ohio EPA or other relevant factors. The director shall provide notice of his designation and the opportunity for public comment on the proposed designation. (B) Final action taken by the director with respect to the designation of an area for implementation of the I/I reduction program is appealable in accordance with Section For purposes of this section, a person may appeal the order if the person lives in or owns property within an area designated for an I/I reduction program Implementation of I/I Reduction Program (A) Investigation: Pursuant to , the director may access the exterior of the property of any person within an area designated by the director pursuant to Section to perform necessary survey work, such as dye testing, smoke testing, or sewer videography. (B) Corrective Measures: Once the director has made the designation authorized by , the director is authorized to implement or contract for the implementation of these corrective measures at private residences, dwellings, buildings, properties, or other structures in the designated areas. Pursuant to , this may include entry onto the property and./or building. (1) The City may take the following corrective measures to reduce the contribution of I/I from private properties:

18 (a) Rehabilitate private sanitary service laterals; (b) Replace damaged private sanitary laterals; (c) Disconnect and redirect downspouts that directly or indirectly connect to private sanitary lateral. A downspout is considered indirectly connected to a foundation drain if it discharges within seven feet of the foundation of the building. Said downspouts may be redirected to the street or at least seven feet from the building. (d) Rehabilitate or replace damaged or poorly functioning downspouts that are currently directed to the street or at least seven feet from the home. (2) With the property owner s written permission, the City may install a sump pump in single family or duplex residential buildings if the building does not have a sump pump. (3) Upon completion of any of the corrective measures set forth in Subsections (1) and (2), the City will restore the property at the City s expense. (D) Post-Implementation Inspection: Upon completion of required corrective measures, the director is permitted to conduct a post-implementation inspection in accordance with If additional corrective measures are required to further reduce I/I, the City will undertake those measures pursuant to this Section. (E) Payment of Costs. The costs of all corrective measures shall be paid by the City. (F) Maintenance: In accordance with this Chapter, the owner of the property shall be responsible for the maintenance of any rehabilitated or replaced private sanitary lateral, redirected downspouts and/or sump pump installed pursuant to this section. Any costs of repair, replacement, or maintenance incurred after the corrective measures taken by the City shall be paid by the owner and shall not be subject to reimbursement by the City. The City will, if applicable, transfer any warranty for the work to the owner of the property Right of Entry; No Trespass Upon presentation of proper credentials and at reasonable times, the director shall have the right to enter the property of any person in the identified areas to perform investigative and survey work pursuant to (A), to enter the property and/or building to perform corrective measures pursuant to (B), and to enter the property and/or building to conduct a post-implementation inspection pursuant to (D). The purpose of the entry is limited to the performance of the investigation, corrective measures, and/or post-implementation inspection outlined. The Director shall provide the owner written notice at least five days in advance of the requested entry, by both leaving a notice at the property and mailing the notice to the billing address. The property owner or occupant shall allow such access to the director. This entry is not a trespass. No person shall forbid the director, or the director s duly authorized representatives to enter, or interfere with their entry upon the property for those purposes. If actual damage is done to the property, the City shall pay the reasonable value of the damage to the property owner. SECTION 4. That the existing Sections and of the Columbus City Codes are hereby amended to reflect the renumbering of the definitions found in Section as follows:

19 Application signatories and certifications. (A) All wastewater discharge permit applications, user reports and certification statements must be signed by an authorized representative of the user and contain the certification statement in Section (A). (B) If the designation of an authorized representative is no longer accurate because a different individual or position has responsibility for the overall operation of the facility or overall responsibility for environmental matters for the company, a new written authorization satisfying the requirements of this section must be submitted to the director prior to or together with any reports to be signed by an authorized representative. (C) A facility determined to be a non-significant categorical industrial user by the director pursuant to Section must annually submit the signed certification statement in Section (B) Certification statement. (A) Certification of Permit Applications, User Reports and Initial Monitoring Waiver. The following certification statement is required to be signed and submitted by users submitting permit applications in accordance with Section ; Users submitting reports on compliance with the categorical pretreatment standard deadlines under Section ; Users submitting periodic compliance reports required by Section , and users submitting an initial request to forego sampling of a pollutant on the basis of Section (C). The following certification statement must be signed by an authorized representative as defined in Section : I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, included the possibility of fine and imprisonment for knowing violations. (B) Annual Certification for Non-Significant Categorical Industrial Users. A facility determined to be a non-significant categorical industrial user by the director pursuant to Section must annually submit the following certification statement in accordance with the signatory requirements in Section (A). This certification must accompany an alternative report required by the Director: Based on my inquiry of the person or persons directly responsible for managing compliance with the categorical pretreatment standards under 40 CFR [specify applicable national pretreatment standard part (s)], I certify that, to the best of my knowledge and belief that during the period from, to, [months, days, year]: (a) The facility described as [facility name] met the definition of a nonsignificant categorical industrial user as described in Section (b) The facility complied with all applicable pretreatment standards and requirements during this reporting period; and (c) The facility never discharged more than one hundred (100) gallons of total categorical wastewater on any given day during this reporting period. This compliance certification is based on the following information:

20 (C) Certification of Pollutants Not Present. Users that have an approved waiver based on Section (B) must certify on each report with the following statement that there has been no increase in the pollutant in its waste stream due to activities of the user: Based on my inquiry of the person or persons directly responsible for managing compliance with the pretreatment standard for 40 CFR [specify applicable national pretreatment standard part(s)], I certify that, to the best of my knowledge and belief, there has been no increase in the level of [list pollutant(s)] in the wastewater due to the activities at the facility since filing of the last periodic report under Section (A). SECTION 5. That the existing Sections and of Columbus City Codes are hereby repealed. SECTION 6. That this ordinance shall take effect and be in force from and after the earliest period allowed by law.

21 REPORT ON INFILTRATION AND INFLOW IMPACTS ON THE CITY OF COLUMBUS SEWER SYSTEM City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP

22 BACKGROUND In 2002 and 2004, the City of Columbus entered into two consent orders with the Ohio Environmental Protection Agency, one for sanitary sewer overflows and one for combined sewer overflows. The 2002 consent order requires elimination of sanitary sewer overflows and water in basement events. The 2004 consent order calls for a reduction in combined sewer overflows. In 2005, the City submitted a Wet Weather Management Plan to the Ohio Environmental Protection Agency to comply with the consent order requirements for sanitary sewer overflows and combined sewer overflows. The Wet Weather Management Plan, which was conditionally approved by the Ohio Environmental Protection Agency in 2009, recommended collection system and wastewater treatment plant improvements. A large portion of the combined sewer system and wastewater treatment plant improvements have since been constructed. However, the large sanitary sewer system improvements have not yet started. Sanitary sewer overflows and water in basement events occur when rainwater finds its way into sanitary sewers that are not designed to handle large amounts of rainwater. This is referred to as infiltration and inflow (I/I). The Wet Weather Management Plan recommended controlling these sanitary sewer overflows in large part by constructing two deep tunnels, known as the Alum Creek Relief Tunnel and the Olentangy Relief Tunnel. Tunnels would take the excessive water in the sanitary sewers and transport it to the wastewater treatment plants. In 2012, the City began looking at whether it could control sanitary sewer overflows without relying solely on tunnels by eliminating the excessive rainwater which enters collection system as infiltration and inflow from getting into the sanitary sewers in the first place. This would require reducing or eliminating infiltration and inflow from private property, as a majority of the infiltration and inflow in Columbus system is coming in from private property. On September 15, 2015, the City of Columbus submitted its Integrated Plan and 2015 WWMP Update Report to Ohio EPA. This Plan was the result of the analysis the City performed to determine if it could solve its SSO and WIB problems without relying solely on tunnels. The Plan presented a preferred alternative, known as Blueprint Columbus, that would focus primarily on solving SSOs and WIBs by removing I/I. The Plan includes a 20 year schedule for eliminating SSOs, and includes some gray infrastructure as well. The Plan is available at The purpose of this Report on the Impact of Inflow and Infiltration is to document and summarize available information regarding the impact of infiltration and inflow on sanitary sewers in general, and more particularly on Columbus sanitary sewer system, including private property impacts. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 1

23 DEFINITIONS Consent Orders - The 2002 SSO Consent Order and the 2004 CSO Consent Order entered between Ohio Environmental Protection Agency and the City of Columbus. Designed Sewer Relief - A structure in a sanitary sewer system constructed prior to the Clean Water Act to allow overflow from the sanitary system if flows are high. Typically installed to reduce water in basement occurrences, with the overflow discharge to the environment through a connection to a storm sewer or directly to a waterway. Downspouts - The vertical infrastructure installed to carry rain collected in gutters from a roof to the ground. Infiltration Inflow - Stormwater and groundwater that enter a sanitary sewer system through such means as defective pipes, pipe joints, connections, or manholes. Infiltration does not include inflow. Stormwater and groundwater that enters a sanitary sewer system, from such sources as, but not limited to, roof leaders; cellar, yard and area drains; foundation drains; cooling water discharges; drains from springs and swampy areas; manhole covers; cross connections from storm sewers; combined sewers; catch basins; storm waters; surface runoff; street wash-waters; or drainage. Inflow does not include, and is distinguished from, infiltration. I/I The combination of infiltration and inflow. Private Sanitary Lateral - The pipe from a building to the public sewer that carries wastewater. Sanitary Sewer Overflow - An overflow, spill, or release of wastewater from a sanitary sewer system. Water in Basement Event - Wastewater backups into buildings that are caused by wet weather flow conditions in a sanitary sewer main. Water in basement events do not include dry weather events. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 2

24 CITY OF COLUMBUS SEWER SYSTEM The City of Columbus sewer system contains combined sewers, sanitary sewers and storm sewers: The combined sewer system covers approximately 7% of the total City of Columbus sewer service area [1] and contains 156 miles of combined sewer [2]. These sewers collect both sanitary waste from homes and businesses and combine it with rainwater collected from streets and roofs. The combined sewer system serves the downtown area and older areas proximate to the downtown area. The combined sewer system is not the focus of this report and will not be discussed further. The sanitary sewer system accounts for 93% of the serviced area [1], totaling approximately 2,481 miles with sewer sizes ranging between 8 inches to 13 feet in diameter [2]. 81% of these sewers are less than 18 inches in diameter [2]. These sewers are intended to collect only sanitary waste from homes and businesses. In addition to the combined sewer system and the sanitary sewer system, approximately 1,757 miles of storm sewers, carrying water from rain storms, are within the City s boundary and run in parallel with the sanitary sewers [2]. Sanitary Sewer Overflows Sanitary sewer overflows (SSOs) are discharges of wastewater from the sanitary sewer system into the environment. Most sanitary sewer overflows occur at a designed sanitary relief (DSR) point during heavy rain events. Designed sanitary reliefs are locations where the sanitary sewer is deliberately connected to a storm sewer. These connections were created in the past before the present requirements of the Clean Water Act and were installed to protect basements from flooding when the sanitary sewer becomes surcharged. When the sanitary sewer becomes surcharged, the designed sanitary relief allows the excess flow to discharge into a storm sewer, and from the storm sewer into rivers or streams. This event is known as a sanitary sewer overflow. In the City of Columbus there are 70 designed sanitary relief locations, down from 100 at the time of the consent order [2]. These sites are owned and monitored by the City of Columbus. The designed sanitary relief locations are noted on Figure 1. Records of the occurrences and volume of overflows (if known) are maintained by the City as required by the consent decrees and the data is updated monthly [3]. Figure 2 summarizes the City s history of sanitary sewer overflow activations over the last five years. Sanitary sewer overflows are prohibited by the Clean Water Act [4]. As noted above, in 2002, the City of Columbus and Ohio Environmental Protection Agency (EPA) entered into a consent order which requires the City to stop sanitary sewer overflows and water in basement events [5]. Sanitary sewer overflows to the environment are a public health threat. Sewage contains a variety of harmful pathogens which can cause illness if ingested [6]. Sanitary sewer overflows empty into City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 3

25 local streams where people can be at risk of exposure when swimming in the water, through drinking from a contaminated water supply, or eating contaminated fish or shellfish [7]. Water In Basements Wet weather water in basement events occur when the City s collection system is full and sewage backs up into basements. This report focuses on water in basement events that are a result of flow conditions in the sanitary sewer main, not the private sanitary lateral which connects the building to the sewer system. The City of Columbus tracks water in basement reports and investigates their cause. Elimination of water in basement events is a requirement of the sanitary sewer overflow consent order. Exposure to sewage from a water in basement event persists through the time of cleanup and restoration [6]. Water in basement events also create an environment that promotes mold growth which can cause health issues for the inhabitants [6]. It has been the policy of the City to reduce water in basement events due to human health concerns. In July of 2004 the City of Columbus began the Project Dry Basement program which installs backflow prevention devices for single and two-family houses in order to reduce citizen exposure to sewage [9]. Figure 3 shows the locations in the City where water in basement events occurred between August 1, 2012 and July 31, City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 4

26 INFILTRATION AND INFLOW CAUSE SANITARY SEWER OVERFLOWS AND WATER IN BASEMENT EVENTS During dry weather, Columbus sanitary sewer system provides a high level of performance. However, during some wet weather events sanitary sewers become surcharged, which causes the sewer to discharge through a designed sanitary relief, which is known as a sanitary sewer overflow. The surcharging in the sewer happens when rainwater in the form of inflow and infiltration enters the sanitary sewer system and exceeds sewer capacity. Inflow refers to rainwater that enters the sanitary sewer directly. For instance, rainwater can enter the sanitary sewer system via flooding around an open manhole lid. Rainwater can also enter the sanitary sewer system through downspouts that are directly connected to a private sanitary lateral. Direct downspout connections to the sanitary sewer are illegal. In 1907 City Council enacted an ordinance which prohibited connections of downspouts to the sanitary sewer system [10]. In 1927, an additional ordinance was enacted that provided the City with the authority to remove any such connections [10]. Downspouts are supposed to discharge to the storm sewer system or storm lateral. However, there are still some illegally connected downspouts on Columbus system [1]. Sump pumps may also be illegally connected to private sanitary laterals [11]. In the above instances rainwater is directly flowing into the sanitary sewer system. Inflow has a very fast response and causes a rapid increase in flow in the sanitary sewer system. The infiltration pathway is slower, but generally has a longer duration in comparison to inflow sources. Infiltration sources into the sanitary sewer system include cracks in pipes surrounded by groundwater, non-watertight joints in pipes and foundation drains that collect water from around a house that then discharge into the private sanitary lateral. Sanitary sewers are not designed to carry large amounts of rainwater. A reasonable factor of safety is included in the design of sewers to guard against some infiltration and inflow. According to the City of Columbus Sanitary Sewer Design Manual the sewers installed in the City of Columbus do allow for approximately 1,940 gallons of infiltration per day for each acre (0.003 cfs/acre) contributing to the sewer. This is part of the sewer s designed capacity [12]. Thus, the sources of inflow and infiltration discussed above may cause the sanitary sewer to become overwhelmed during heavy rain events beyond the designed sewer capacity. This results in sanitary sewer overflows and water in basement events. The impact of inflow and infiltration on the City of Columbus sanitary sewers has been studied extensively. As discussed, the City submitted a Wet Weather Management Plan to the Ohio Environmental Protection Agency in 2005 to address the consent order requirements. The WWMP identified twelve Priority Areas where significant sanitary sewer overflows and water in basement events were occurring. In 2006 the infiltration and inflow studies were initiated based on the WWMP recommendation, and once started the areas of study were expanded well beyond the City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 5

27 initial Wet Weather Management Plan recommendations. In total over 10,000 acres have been studied [13]. The purpose of the studies was to determine the sources of infiltration and inflow in the areas where sanitary sewer overflows are occurring. In conjunction with the infiltration and inflow studies performed by the City since 2006, the City has and continues to utilize an extensive network of sanitary sewer system flow meters and rain gauges to collect data on the sewer system wet weather performance. The City also operates and maintains an extensive and detailed computer model of the collection system based upon the data collected by the flow meters and rain gauges. The system flow metering and computer modeling has identified a total of 18,000 additional acres that contribute significant infiltration and inflow that is causing sanitary sewer overflows and/or water in basement events [14]. The 18,000 acres of significant infiltration and inflow have been designated as Blueprint Columbus target areas for inflow and infiltration reduction, and are shown on Figure 4. The City used it model to predict the results of applying inflow and infiltration technologies to these 18,000 acres. The result is result is a dramatic lowering of incidences of SSOs and WIBs. However, to eliminate the overflows will also require some additional gray infrastructure, such as relief pipes. The details of the model results and the exact plan for elimination can be found in the Sept. 15, 2015 Integrated Plan. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 6

28 INFILTRATION AND INFLOW STUDY FINDINGS The infiltration and inflow studies discussed above analyzed both public and private sources of infiltration and inflow. Private sources of infiltration and inflow are entering the City s system from private property, as opposed to entering directly into the City s system from publicly owned property such as the right-of-way. In general, it was found that more than half of the infiltration and inflow was getting into the sanitary system from private sources [13, 15]. As discussed in this section, that finding is consistent with other studies that have been performed around the country. Residential Sources of Private Infiltration and Inflow As shown in the illustration, the private sanitary lateral connects the home to Columbus sanitary sewer main. This illustration also points out the ways that an individual home can contribute infiltration and inflow to the sanitary sewer. The inflow source shown on the figure is a roof drain (downspout) that is directly connected to the foundation drain. This connection would rapidly fill the foundation drain with rainwater and enter the private sanitary lateral feeding the sanitary sewer. This connection was made illegal in 1907 [10]. The rainwater in the foundation drain can enter the private sanitary lateral through the 4 inch to 6 inch transition in the lateral and other joints on the lateral. The 4 inch to 6 inch transition connects the house plumbing (4 inches in diameter) with the private sanitary lateral (6 inches in diameter). This connection is typically not water tight. The joints on older clay lateral pipes are typically not watertight either. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 7

29 Two potential infiltration pathways are shown. The first is a downspout emptying on a splash block that is near the foundation of the house. The rain percolates through the soil then collects in the foundation drain which connects (directly or indirectly) to the private sanitary lateral. The second source is cracks and imperfect joints in the private sanitary lateral itself. These cracks and imperfect joints allow groundwater and stormwater from the lawn area above to leak into the private sanitary lateral into the sanitary sewer system. These conditions are typical for houses in the Blueprint Columbus areas as indicated in Figure 4, and lead to infiltration and inflow greater than designed capacity. Columbus Infiltration and Inflow Studies Confirm Private Residential Contribution Approximately 20% of properties tested during Columbus infiltration and inflow studies conducted since 2006 indicated that infiltration was occurring at the 4 inch to 6 inch transition in the lateral [13]. These studies also indicate that infiltration and inflow into private sanitary laterals was either the primary source or a very significant contributor to excessive water into the sewer system [13]. In the infiltration and inflow studies done in the Linden/Northeast Area study area, approximately 60% of infiltration and inflow was attributed to the downspouts, sanitary laterals, sump pumps or foundation drains found on private property [13]. For the James/Livingston area 42% of tested properties had sanitary lateral infiltration [13]. In addition to the infiltration and inflow studies, another pilot study performed by the City confirms the substantial contribution of infiltration and inflow from older homes. In certain areas of Clintonville, there were frequent water in basement events and surcharging (overwhelmed) sewers. Between July 2005 and March 2007 the City rehabilitated mainline sewers and manholes within the public right-of-way in this area to address the infiltration and inflow problem [17]. However, after sealing the public side of the sanitary sewer system, monitoring showed only limited infiltration and inflow reduction. This indicates that private sources continue to contribute substantially to the problem. To further test the contribution of private sources of infiltration and inflow, the City of Columbus then implemented a voluntary private sanitary lateral rehabilitation program for Clintonville. Two areas, totaling 216 households, were selected for the voluntary program [18]. Testing in the area indicated between 5-8% of the houses had downspouts directly connected to the private sanitary laterals, 51-53% of the homes had foundation drains connected to the private sanitary laterals, and 33-35% of the homes had experienced water in basement events [18]. The foundation drains were the main component contributing to infiltration and inflow from the private sources [18]. Between 86% and 87% of the residents volunteered for private sanitary lateral replacement/repair [19]. Continued monitoring indicates that the voluntary private sanitary lateral repair project was effective at reducing infiltration and inflow by approximately 30% [20]. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 8

30 For Columbus system, the studies determined that there are two main sources of infiltration and inflow from private sources: private sanitary laterals in poor condition, and downspouts directly or indirectly connected to the sanitary sewer by the foundation drain. Each of these two sources of infiltration and inflow are discussed in more detail below. Other Cities Studies Also Confirm the Private Contribution In Duluth, Minnesota a program to disconnect foundation drains from private sanitary laterals proved to be very successful in achieving substantial reductions in wet weather peak flows, volumes, and sanitary sewer overflow activations [21]. New Castle County, Delaware also embarked on a program to eliminate illegal private inflow sources to the sanitary sewer including sump pumps, punctured floor drains, and leaky basement drains. After a pilot program was implemented reductions in wet weather peak flows and volumes were observed in the sanitary mainline sewers, including a 55% reduction in peak wet weather flow rate, and a 27% reduction in total storm volume based on flow metering data [11]. Johnson County, Kansas had issues with water in basement events and sanitary sewer overflows. After disconnecting unpermitted inflow sources on private property, water in basement complaints have decreased and sanitary sewer overflow activations and volumes have been reduced [16]. The Water Environment Research Federation analyzed twelve projects conducted by six utilities across the country for their effectiveness in reducing peak infiltration and inflow. The results showed that infiltration and inflow improvements conducted in the public right-of-way provided little reduction in peak infiltration and inflow, most projects showed a reduction of 5% or less. However, projects that addressed private sanitary laterals realized significant reduction in peak flow and reductions between 50 and 70% were realized [22]. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 9

31 PRIVATE INFILTRATION AND INFLOW As discussed above, Columbus studies have determined that there are two main contributors of private infiltration and inflow to the system: laterals in poor condition, and foundation drains. This section will discuss the problem and the solution. Private Sanitary Laterals The United States Environmental Protection Agency recognizes that approximately half of the total length of a sewer system is on private property [16]. This means there are over 2,500 miles of private sanitary laterals in Columbus sewer system that are potential sources of infiltration and inflow to the sanitary sewer system. In Columbus the infiltration and inflow studies showed that houses constructed before 1965 have a higher likelihood of leaky and/or defective private sanitary laterals. Construction of private sanitary laterals was improved after the plumbing code and plastic pipe updates that occurred in the 1960s; nonetheless, these laterals will also deteriorate over time. [23]. The studies analyzed by the Water Environment Research Federation indicated that replacement or lining of laterals were effective methods for repairing private sanitary laterals [22]. The study indicated that cured-in-place-pipe lining has been successfully used; however, at the time of the research this technology had not been widely used. Cured-in-place-pipe lining creates a new pipe within the existing pipe that has no joints, or cracks that can introduce infiltration into the pipe. The study also describes several instances where total replacement of the private sanitary lateral was the focus of the study. This would require excavation of the current private sanitary lateral and installation of a new lateral [22]. Recently, cured-in-place-pipe technology has become more widely used for repairing both the sanitary sewer system and private sanitary laterals. There has been a rapid growth in the application of cured-in-place-pipe technology because it is recognized as being cost effective in reducing infiltration and inflow [24]. The City of Columbus has used cured-in-place-pipe to repair mainline sanitary sewers for many years. Columbus, through small pilot projects, has also tested cured-in-place pipe to repair private sanitary laterals. The City finds this technology effective to reduce infiltration and inflow. Cured-in-place-pipe, and if needed, complete private sanitary lateral replacement are effective methodologies that can be utilized to reduce the infiltration and inflow from private sanitary laterals. Pipe bursting is another trenchless technology that can be an effective remediation technology. This technology involves destroying the old sewer and replacing it with a new pipe. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 10

32 Foundation Drains Current state and national building codes require that homes have their rooftops drain to gutters which channel the water to the downspouts that are connected to storm laterals which, in turn, take rainwater to the street or discharge the rainwater away from the house foundation [25]. It has been illegal to have downspouts directly connected to sanitary sewers in Columbus since 1907 [10]. The infiltration and inflow studies found that houses constructed before 1935 have a higher likelihood of directly connected downspouts. In addition, current standards require that the foundation drains be connected to a sump pump that also discharges to the street or away from the house. This has been part of the Columbus City Code since 1963 [26]. Foundation drains on houses built before 1963 were legally connected (directly or indirectly) to the private sanitary lateral, and thus connected to the City s sanitary sewer. While direct connections of roof water to the sanitary sewers are now prohibited, roof water is still having a major negative impact on the sanitary sewers for two reasons. First, the infiltration and inflow studies have found that some downspouts are still directly connected to the sanitary sewers, although a relatively small number of houses are connected in this way [13]. Secondly, roof water is also impacting the sanitary sewer through indirect connections to the foundation drains. Studies have determined that if water is discharged to the ground near the home, the water migrates down the side of the foundation to the foundation drain, and through the foundation drain to the City s sanitary sewer [13]. This indirect connection is more common and a more significant contributor than direct connections. System flow metering and computer modeling performed by the City was used to determine the extent of the indirect connection caused by the foundation drain. The City of Columbus has maintained an extensive computer-based sewer system model since This model is continuously refined and updated to the latest standards of performance. The model provides information concerning the performance of the sewer system under varying circumstances. The sewer system model indicates that a four to six foot area around a house could be a significant source of infiltration to the sewer system. This area collects both direct rain and runoff from the roof via gutters and downspouts that are not connected to the street. This rainwater percolates through the soil and collects around the foundation drain which introduces water to the private sanitary lateral in areas where sump pumps are not installed. Therefore, it is recommended that roof water be discharged at a distance of at least seven feet from the house, so as to not impact the foundation drainage [14]. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 11

33 In order to prevent roof water from indirectly being connected to the sanitary sewer, it is necessary to move the downspout discharges more than seven feet from the house and the grade from the house must slope downward from the house [14]. Simply discharging downspouts to small splash blocks is ineffective at reducing infiltration and inflow; water from the downspout quickly finds its way to the foundation, and then goes to the foundation drain. Removal of this defect is known as roof water redirection. Replacing or adding storm laterals which carry downspout flow to the street, and downspout disconnection, are the most effective way to eliminate roof drainage from entering the private sanitary lateral. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 12

34 SUMP PUMPS AND DISCONNECTION OF FOUNDATION DRAINS PROVIDE HIGHEST LEVEL OF PROTECTION As discussed above, foundation drains are a significant source of infiltration and inflow. Roof water redirection will greatly reduce this contribution. However, while roof water redirection will reduce the contribution of infiltration and inflow from foundation drains, it will not eliminate it, as the foundation drain is still connected to the separate sanitary sewer. Additional reductions can be achieved if the foundation drain is physically disconnected and the 4 inch to 6 inch connection is sealed. Such a disconnection would require installation of a sump pump. Sump pumps collect water from the foundation drain and discharge the water to the street. Typically, sump pumps discharge to the street curb through a storm lateral then drain to the inlet of the storm sewer system. Sump pumps could collect a large amount of water and pump it out to the street, or at least seven feet from the house. Sewer system modeling incorporating varying levels of sump pump installations revealed that sump pumps have a significant impact on the amount of infiltration observed in the sanitary sewer system. These results highlight that discharge of rainwater at a distance of at least seven feet from the house and sealing the 4 inch to 6 inch connection could significantly control infiltration into the sewer system [14]. However, not all homes have sump pumps. Sump pumps became a requirement as part of the changes in the Columbus City Code in 1963 [26]. All new homes constructed since 1963 have sump pumps that commonly discharge to the street. While lateral lining and roof water redirection should provide a significant reduction in inflow and infiltration, sump pumps provide a higher level of protection. Therefore, where possible, the City would like to install sump pumps in the affected areas. [18]. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 13

35 CONCLUSION The City of Columbus is under consent orders to eliminate sanitary sewer overflows and water in basement events. These events occur when the sanitary sewer becomes overloaded as a result of infiltration and inflow into the separate sanitary system. In Columbus, the majority of the infiltration and inflow is coming from private property, and more specifically, from residential laterals that are in poor condition, and from residential downspouts that are connected directly or indirectly to the sanitary sewer. Columbus sanitary sewer overflows and water in basement events are caused by the infiltration and inflow coming from these residential areas, which comprise approximately 18,000 acres. Modeling has confirmed that addressing the infiltration and inflow from these areas will reduce sanitary sewer overflows and water in basement events in these areas. It is recommended that the infiltration and inflow problem be addressed by the City taking the following steps in the Blueprint areas (Figure 4): Continuing to line its main line sewers; Lining all private residential laterals; Installing sump pumps where possible; and Redirecting downspout discharge at least seven feet from the homes. Together, these steps should significantly mitigate the impact of inflow and infiltration and thus lead to the elimination of sewer overflows and water in basement events. City of Columbus November 9, 2015 Engineer s Report on Infiltration and Inflow CIP Page 14

36 I Miles CITY OF COLUMBUS DIVISION OF SEWERAGE AND DRAINAGE SEWER SYSTEM CAPACITY MODEL UPDATE 2012 DSR LOCATIONS FIGURE 1

37 Figure 2 - City of Columbus Sanitary Sewer Overflows Number of Events Annual Rainfall, inches Year Wet events Dry events Annual Rainfall 200

38 I Miles CITY OF COLUMBUS DIVISION OF SEWERAGE AND DRAINAGE SEWER SYSTEM CAPACITY MODEL UPDATE 2012 WIB LOCATIONS (08/01/12-07/31/13)) FIGURE 3