📍 Westerville, OH — Serving Central Ohio · Mon–Fri 9:00–4:30 Lifetime Leak-Free Guarantee
The Open Shower Co. — walk-in showers and bath remodeling
(614) 423-9766 Build Your Price
Central Ohio water and plumbing

The sewer lateral and the drains under a Central Ohio house

A sewer lateral is the four to six inch pipe that carries everything from a house to the public sewer, and in Central Ohio it is almost always the household's to maintain. Where that responsibility ends is a separate question, and the systems that publish an answer do not agree with each other. This page covers what the pipe is made of era by era, how it fails and how a camera reads it, why an old foundation drain and a heavy rain arrive in a basement together, and the plumbing code rules a tub-to-shower conversion has to meet. Every figure, date and code section here is a city's, a district's or the state's own, read in September 2026.

Last updated September 2026 · Code sections, city documents and figures are the state's, the cities' and the EPA's own, read September 2026 · No prices on this page; the Estimate Builder carries those · Part of the knowledge base

What a lateral is, and where it runs

The pipe that carries everything from a house to the public sewer is called a lateral. The City of Columbus says lateral pipes are typically four to six inches in diameter and run underground, connecting a home's plumbing to the City's sanitary sewer system. The City's Construction and Material Specifications give the same pipe a longer name and fix its extent: a sanitary house connection service runs from the wye fitting on the main line lateral sanitary sewer to the building drain adapter. The street sewer is at one end and the drain under the house at the other.

Who is responsible for it

Ohio law settles the supervision and says nothing about the bill. Ohio Revised Code section 3781.03 gives the city engineer's department, the boards of health of health districts, or the sewer purveyor complete authority over the whole sewerage and drainage system in their jurisdiction, including, in the statute's words, the building sewer and all laterals draining into the street sewers. The same sentence sits in the Ohio Plumbing Code at Section 701.1. Supervision is not ownership, and not a duty to repair.

The City of Columbus says homeowners are responsible for maintaining their lateral pipes while the City is responsible for keeping the City-owned portion of the system in good working condition. What no City document read for this page says is where the first of those ends and the second begins. The lateral lining brochure, the Blueprint Columbus program pages and the City's own list of sewer questions were read looking for that line, and none draws it. The Columbus City Code itself could not be read; the site hosting it refused every request.

Ohio systems that do publish a boundary do not agree on where it sits; each row below is one system's own wording.

SystemWhere the owner's responsibility runs, in that system's own document
City of ColumbusHomeowners maintain their lateral pipes; the City keeps the City-owned portion in good working condition. Where the two meet is not stated.
City of YoungstownThe owner is responsible for the building sewer all the way to the sewer main, including any portion lying within the public right of way.
City of HamiltonThe owner operates and maintains the service line from the premises to the City right-of-way or easement; the City may repair or replace the portion inside it at its own discretion.
City of AkronHomeowners are responsible for structural repairs from the home to the right-of-way or easement line; the City is responsible from there to the sewer main.
Delaware County Regional Sewer DistrictThe service line is the lot or parcel owner's from the branch joint of the wye on the District's main, and the owner is responsible for its operation and maintenance.

Only the Delaware County district there is a Central Ohio authority; the three cities are in the table because the rule is local, not statewide. The Youngstown row is quoted from a copy of that city's codified ordinances posted by a code publisher, and that copy could not be opened again when this page was checked. Elsewhere, a homeowner has to ask the authority that serves that address.

Work by the City does not move the responsibility. Under Blueprint Columbus the City may line an aging lateral; it says it selects the contractor, that a lined lateral has a life expectancy of fifty years, and that the homeowner still maintains it. The program belongs to the page on the Columbus sewer system.

What the pipe is made of, era by era

The City of Columbus says that in older homes the lateral is usually clay pipe, which over time becomes cracked or filled with tree roots. That is half the picture, because the City's own specification, in its online version of January 1, 2023, still lists extra strength vitrified clay pipe beside PVC and ductile iron as an accepted material for a new sanitary house connection service. Clay says very little about a pipe's age. Where Ohio's clay sewer pipe was made is on the page about what Ohio made for houses.

The joint says more. A 1985 paper by two clay pipe industry engineers, reprinted by the American Society of Civil Engineers' Pipeline Division, gives the sequence: oakum and cement mortar before the Second World War, a rigid joint that does not tolerate earth movement; hot-poured compounds after it; then factory-applied compression joints, with ASTM C425 adopted in 1958. It is the industry writing about its own product.

Bituminous fiber, sold as Orangeburg

Orangeburg is a brand name; the fullest government account found for this page, from the building department of Ann Arbor, Michigan, describes the generic product as bituminous fiber pipe, made of cellulose and asbestos fibers impregnated with a bituminous coal-tar compound. The same account says there are no specific records that can be used to fix the exact time span in which the pipe was used, and offers the early 1950s to the early 1970s only as a reasonable assumption for its own city. Its firmer dates are Michigan's: state acceptance as of November 1, 1949, removal from Ann Arbor's approved materials effective May 1970. No Ohio approval or ban date was found at all.

Ann Arbor describes the failure. The pipe flattens under the earth pressure around it and loses the circular cross section it needs, and its inspectors have seen pipe still round on the outside while failing and out of round inside. In most houses there, it says, the pipe probably ran from a point about five feet outside the foundation wall to the city main, which makes it a yard problem rather than a bathroom one.

Cast iron, plastic and galvanized steel

The old joint inside the house is not history. The Cast Iron Soil Pipe Institute counts roughly one and a half billion no-hub couplings installed in North America since 1961. The joint they replaced, oakum packed firmly and molten lead poured in one operation to a depth of not less than one inch, is still specified in the current Ohio Plumbing Code at Section 705.3.1.

No Ohio or Columbus source found for this page dates the arrival of plastic drain pipe here. Ann Arbor's building department puts it in the early 1970s, when it says plastic piping materials began to be more commonly used; that is a Michigan statement about a Michigan city. Galvanized steel is exact: the Ohio Plumbing Code lists galvanized steel pipe among the materials allowed for above-ground drainage and vent piping, and not among those allowed for underground building drainage.

Outside the wall the state code declines to answer. Ohio deletes Section 702.3, Building sewer pipe, deletes its materials table and deletes Section 703 entirely, so what a lateral may be made of has a local answer, which in Columbus is the City's specification.

How a lateral fails, and how anyone knows

Roots come in at the joints. Ann Arbor's building department puts it plainly: tree roots may invade the pipes, usually at the joints, and as they do they loosen or break apart pipe sections and restrict flow. The City of Columbus describes the same failure more mildly, as an older clay lateral becoming cracked or filled with tree roots. Both treat root intrusion as a leading cause of failure in old pipe.

A lateral in Columbus is read from the street, not from the house. The City says a remote camera can access the lateral from inside the city's sewer main, and that only when tree roots or another obstruction block the camera does it become necessary to insert it through a sewer cleanout in the home's basement. A transmitter inside the camera lets the crew map the lateral's route from the surface.

Access is the practical constraint. The City's specification puts cleanouts no more than a hundred feet apart on its own sewer work, and the Ohio Plumbing Code requires a cleanout at the junction of the building drain and the building sewer, or within ten feet upstream of it. Where a building drain is replaced by pipe-bursting, the code requires a recorded video camera survey before and after, and the survey made beforehand must note the position of the cleanouts and the depth of the connections.

The Ohio Plumbing Code names two trenchless methods and separates them by size: pipe-bursting, limited to gravity drainage piping six inches and smaller, and relining, limited to gravity drainage piping four inches and larger, with the replacement piping the same nominal size as the existing. Ohio then strikes the words for underground building sewers out of the pipe-bursting section and deletes the cured-in-place section for building sewers and service laterals altogether, so the state plumbing code's trenchless rules stop at the wall of the house.

Rain in a sanitary sewer, and what backs up

A foundation drain is a perforated pipe laid around the perimeter of the basement or foundation to collect ground and surface water. The City of Columbus says that in homes built before the 1960s that drain connects directly to the sanitary sewer, and that sump pumps have been a standard requirement in new homes since the mid-1960s.

The Environmental Protection Agency separates the two ways water reaches a sanitary sewer. Inflow is water that enters from sources such as roof leaders and cellar or foundation drains. Infiltration is water that enters from the ground through defective pipes, pipe joints, connections or manholes. Neither includes the other, and an old house supplies both: the tied-in foundation drain is inflow, the cracked clay joint infiltration.

The City of Columbus states the mechanism plainly. Cracks and leaks in lateral pipes let rain water into sanitary sewers that were never meant to hold it, the pipes fill beyond their capacity, and the result is sewage overflowing into rivers or backing up into basements. It is equally plain about its sump pump work: the goal it states is keeping rain water out of the sanitary sewer system rather than drying basements, and it says there is no guarantee a pump will keep rain water out of one.

Whether that water may go to the sanitary sewer is a local question. The Delaware County Regional Sewer District prohibits discharging into a building sanitary sewer the surface water that collects in basement or foundation excavations or in foundation or footer drains, and separately bars storm water, groundwater, sump pump discharge and roof runoff. A house in Columbus, or in a suburb with its own system, is under that jurisdiction's own rules, not Delaware County's.

The rules a tub-to-shower conversion actually meets

Start with the code, because the usual answer is wrong. The Residential Code of Ohio has one plumbing chapter and it carries almost no rules of its own: its Section 2501.1 incorporates the provisions of the Ohio Plumbing Code and then modifies exactly two rules, the shower lining rule and the trap seal rule. The Ohio Plumbing Code is the International Plumbing Code, 2021 edition, chapters 2 through 15, adopted by reference and amended by Ohio rule. One caution before quoting a section number: the residential code's referenced-standards table still names an earlier edition, and the two number the same rules differently, backwater valves being Section 714 in the current edition and 715 in the older. Ask the building department that will inspect the work which edition it applies. Who inspects, and who holds the state license, belong to the page on the Ohio plumbing code.

In the plumbing code's fixture table a bathtub, and a shower whose showerheads and body sprays together deliver 5.7 gallons a minute or less, each count as two drainage fixture units and each need a trap no smaller than one and a half inches. A footnote adds that a showerhead over a bathtub does not increase the drainage fixture unit value at all. A tub-to-shower conversion therefore does not by itself ask the drain to grow. Above 5.7 and up to 12.3 gallons a minute the trap becomes two inches and the load three fixture units, and the two bands above reach three and four inches. It takes a second showerhead or a bank of body sprays to cross that first line.

The shower's own outlet is smaller than most people guess. The Ohio Plumbing Code sets waste outlets serving showers at not less than one and a half inches in diameter, with a removable strainer of not less than three inches across on everything but a bathtub outlet. Every plumbing fixture is to be separately trapped by a liquid-seal trap and is not to be double trapped, and Ohio's residential rule holds the water seal to not less than two inches and not more than four. Several traps found in old bathrooms are prohibited outright by the same code: S traps, drum traps, bell traps, crown-vented traps and any trap that depends on moving parts to hold its seal.

What usually decides where a new drain can sit is the vent. Every fixture trap has to have a protecting vent, and the Ohio Plumbing Code caps the distance between them: six feet from a one and a half inch trap at a quarter inch per foot of slope, eight feet for a two inch trap. Where a whole bathroom group is reworked one pipe may do both jobs, the same code permitting any combination of fixtures within two bathroom groups on the same floor level to be vented by a horizontal wet vent. Those two rules decide what can move in a small room, which the five-by-eight bathroom page works through.

Two rules sit at the ends of the job. The shower liner is one of the only two plumbing rules the Residential Code of Ohio writes in its own words: it must turn up on all sides at least two inches above the finished threshold, must not be nailed or perforated within an inch of that, and must be pitched a quarter unit vertical in twelve units horizontal toward the drain, with an exception for a sheet-applied, load-bearing, bonded waterproof membrane. In a basement, two devices that get merged in conversation are separate. A fixture that cannot drain to the sewer by gravity has to discharge into a tightly covered and vented sump and be lifted by automatic pumping equipment, and Ohio requires only a check valve on the discharge piping in a house. A backwater valve is not standard equipment in Ohio: one is required only where the Ohio Environmental Protection Agency or the local sewer purveyor calls for it, and then only for fixtures on a floor lower than the manhole cover of the next upstream manhole in the public sewer. Fixtures above that elevation must not discharge through one, except in an existing building. Central Ohio's flood record, the dams built since and the maps that set flood zones are on the floods, dams, levees and floodwalls page. What a conversion covers as a job is on this site's tub-to-shower conversion page.

The short version. The lateral is the four to six inch pipe from the house to the public sewer. The City of Columbus says the household maintains it and never says where the City's own portion begins; the systems that do publish a boundary publish different ones. Clay is still an accepted material here, so the joint dates a pipe rather than the material, and roots enter at joints. The state plumbing code stops at the wall of the house. Inside it, a bathtub and an ordinary shower carry the same trap size, and the distance from trap to vent decides more than the size of the drain.

Sources

Every figure, date and quotation on this page comes from one of these documents, read on the date given. Where two of them disagree, the page says so.

Common questions

Who is responsible for the sewer lateral in Columbus, Ohio?

The City of Columbus says homeowners are responsible for maintaining their lateral pipes and that the City is responsible for keeping the City-owned portion of the system in good working condition. No City document read for this page says where the household's part ends and the City's begins. Ohio systems that do publish a boundary publish different ones: Youngstown puts the whole building sewer on the owner, including any portion in the right of way; Hamilton and Akron split it at the right-of-way or easement line; and the Delaware County Regional Sewer District starts the owner's service line at the wye on its main. There is no single Central Ohio answer; a homeowner has to ask the authority that serves that address.

How big is the sewer lateral under a Columbus house?

The City of Columbus says lateral pipes are typically four to six inches in diameter and run underground, connecting a home's plumbing to the City's sanitary sewer system. The City's construction specification describes the same pipe by its ends and calls it a sanitary house connection service, running from the wye fitting on the main line lateral sanitary sewer to the building drain adapter. That four to six inch band also decides how it can be repaired without a trench: the Ohio Plumbing Code limits pipe-bursting to gravity drainage piping six inches and smaller and relining to piping four inches and larger, so a lateral sits between the two limits.

Does a tub-to-shower conversion in Ohio need a bigger drain?

Usually not. In the Ohio Plumbing Code's fixture table a bathtub, and a shower whose showerheads and body sprays together deliver 5.7 gallons a minute or less, each count as two drainage fixture units and each need a trap no smaller than one and a half inches, and a footnote says a showerhead over a bathtub does not increase the fixture unit value at all. The trap goes to two inches only above 5.7 gallons a minute, which takes a second head or body sprays. The distance from the new trap to the existing vent is more often the real constraint, capped at six feet for a one and a half inch trap.

Is clay sewer pipe a problem in an older Columbus house?

Not by the fact of being clay. The City of Columbus says the lateral in older homes is usually clay pipe and that it becomes cracked or filled with tree roots over time, but the City's own specification of January 1, 2023 still lists extra strength vitrified clay pipe as an accepted material for a new sanitary house connection service. What dates a clay pipe is its joint. A 1985 paper reprinted by the American Society of Civil Engineers records oakum and cement mortar joints before the Second World War, hot-poured compounds after it, and factory-applied compression joints, with ASTM C425 adopted in 1958. Roots come in at joints, so the joint is the thing to ask about.

When was Orangeburg pipe used, and is it under Ohio houses?

Nobody appears to have the records to say. Orangeburg is a brand name for bituminous fiber pipe, made of cellulose and asbestos fibers impregnated with a coal-tar compound. The building department of Ann Arbor, Michigan, which published the fullest government account found for this page, says there are no specific records that can be used to fix the exact time span in which it was used, and offers the early 1950s to the early 1970s only as a reasonable assumption for its own city. Its firm dates are Michigan's: state acceptance in November 1949 and a local ban effective May 1970. No Ohio approval or ban date was found.

Why does heavy rain back a sewer up into an older Columbus basement?

The City of Columbus says that in homes built before the 1960s the foundation drain connects directly to the sanitary sewer, and that sump pumps have been a standard requirement in new homes only since the mid-1960s. The City states the mechanism plainly: cracks and leaks in lateral pipes let rain water into sanitary sewers that were never meant to hold it, the pipes fill beyond their capacity, and sewage overflows into rivers or backs up into basements. The Environmental Protection Agency calls water arriving from a foundation drain inflow, and water entering through defective pipes and joints infiltration, and an old house can supply both at once.

Does a basement bathroom in Ohio need a backwater valve?

Not as a matter of course. The Ohio Plumbing Code requires a backwater valve only where the Ohio Environmental Protection Agency or the local sewer purveyor calls for one, and then only for fixtures on a floor lower than the manhole cover of the next upstream manhole in the public sewer; fixtures above that elevation must not discharge through one, except in an existing building. The rule that does apply generally is different: a fixture that cannot drain to the sewer by gravity has to discharge into a tightly covered and vented sump and be lifted by automatic pumping equipment, and Ohio requires only a check valve on the discharge piping in a house.

Which code covers the plumbing in an Ohio bathroom remodel?

The Ohio Plumbing Code, not a plumbing table inside the residential code. The Residential Code of Ohio has one plumbing chapter and it carries almost no rules of its own: its Section 2501.1 incorporates the Ohio Plumbing Code and modifies exactly two rules, the shower lining rule and the trap seal rule. The Ohio Plumbing Code is the International Plumbing Code, 2021 edition, chapters 2 through 15, adopted by reference and then amended by Ohio rule. One caution: the residential code's referenced-standards table still names an earlier edition, and the two editions number the same rules differently, so ask the building department that will inspect the work which edition it applies.

See your actual price in about two minutes

Pick your shower, choose real products with real model numbers, and watch the number move. No phone number required, and nobody will call unless you ask.

Build Your Estimate Call (614) 423-9766