Looking for a cast iron pipe plumber in O'Fallon, IL? Describe your project once and up to three licensed plumbers who work in O'Fallon and St. Clair County get back to you with a quote. It's free and there is no obligation.
O'Fallon is home to about 32,169 people (2024 Census Bureau estimate), a stable community (−0.8% since 2020). With 2,035 people per sq mi, it is a suburban area. Homes built before the mid-1970s often still have cast iron drains reaching the end of their life.
O'Fallon at a glance
- Population (Census Bureau estimate, 2024)
- 32,169 (−0.8% since 2020)
- Rank in Illinois
- 59th of 1,294 cities and towns
- Land area
- 16 sq mi
- Population density
- 2,035 people per sq mi (suburban)
- Type
- City (O'Fallon city)
- Main county
- St. Clair County
What to check before hiring in O'Fallon
- Camera first: a video inspection shows where and how badly the pipe is damaged.
- License and permit: in Illinois, drain work is done by a licensed plumber under a permit.
- Method: ask for both lining and replacement options when possible.
- Price drivers: length, slab access, tunneling, method and restoration.
Useful official resources
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IAPMO: plumbing codes
Official information and guidance.
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NASSCO: pipeline rehabilitation
Official information and guidance.
Services available in O'Fallon
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Cast iron drain replacement
Replacement of cast iron drain lines with PVC, including under-slab work where needed.
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Cast iron pipe lining
Rehabilitation of cast iron drains with an epoxy or cured-in-place liner.
Frequently asked questions in O'Fallon
How much does cast iron replacement cost in O'Fallon, IL?
It depends on the length, the slab and the method. Describe your home: plumbers who serve O'Fallon reply with a quote.
How long does it take?
From a few days for lining to a week or more with tunneling.
Can I stay at home?
Often yes, with limited plumbing use during the work.
Which licensed plumbers will contact me?
Up to three independent licensed plumbers who serve O'Fallon and the surrounding area, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.