Plumbing in Christiana at a glance
- ZIP codes served
- 19702, 19713
- Water supply
- Artesian Water Company
- Wastewater
- New Castle County sewer
- Typical housing stock
- Mixed commercial and 1970s–1990s residential
- Distance from Newark
- approx. 5 miles east of Newark
A corridor, not a neighbourhood
Christiana is unlike anywhere else we work. The Christiana Mall and the ChristianaCare hospital campus anchor a dense commercial corridor of restaurants, retail units, medical offices and hotels — and immediately alongside it sit established residential streets from the 1970s through the 1990s.
Those are two different trades. A residential call is about a household's water. A commercial call is about a business that cannot trade while the water is off, operating under compliance obligations that do not apply to houses.
Commercial work in the Christiana corridor
Grease management
Food service is the defining commercial plumbing category here. Fats, oils and grease congeal as they cool and coat the inside of drain lines, and enough of it blocks the public main downstream — which is why sewer authorities require food service premises to intercept it before it leaves the building.
Three things go wrong routinely:
- Undersized interceptors. Sizing is calculated from fixture capacity and flow. Fit one too small and grease passes straight through, so you get the blockages anyway and a compliance issue.
- Missed cleaning intervals. An interceptor that is not pumped on schedule stops intercepting. Authorities generally require documented maintenance records, not just the device.
- Kitchen line neglect. Even with a correctly working interceptor, the run between the fixtures and the unit accumulates. Scheduled hydro jetting is maintenance here, not a repair.
Backflow prevention
Commercial connections generally carry a requirement for backflow prevention — devices that stop water inside the building being drawn or pushed back into the public supply. Boiler loops, irrigation, fire suppression, chemical handling and medical equipment all raise the stakes.
These devices carry a periodic testing obligation performed by a certified tester, with results filed with the water supplier. If you are a tenant rather than a building owner, establish who is responsible for that testing before you need to. The obligation commonly follows the water account rather than the lease boundary, and "we assumed the landlord handled it" is not a defence.
Tenant fit-out
Retail and restaurant units in this corridor turn over, and each new tenant reconfigures plumbing for a different use. A unit built for retail becoming a café needs entirely new drainage, water supply, venting and grease handling.
The mistakes are consistent: discovering permit requirements after the schedule is set, finding the existing drain is in the wrong place or the wrong size for the new layout, and specifying an interceptor at the end of the design rather than at the start. Delaware plumbing work is inspected by a State Plumbing Inspector, and that scheduling has to be built into your programme. Get a plumber involved at drawing stage rather than at fit-out stage.
Residential Christiana
The housing here is mostly 1970s through 1990s, which puts it in a comfortable middle position. Copper supply, a mix of cast iron and PVC drainage, on Artesian water and New Castle County sewer.
It is old enough that original water heaters are long gone and second or third ones are now failing, that shutoff valves are stiffening, and that cast iron drains installed at the older end of the range are beginning to scale. It is new enough that whole-home repiping is rarely the answer — unlike the pre-1960s housing a few miles west in Newark.
Where cast iron is present, the tell is the same as everywhere: a drain that blocks repeatedly in the same place regardless of what goes down it. That is scale on the pipe wall, not user error, and jetting restores the bore where cabling only punches through.
One thing that catches people out
Mixed-use buildings and shared services
Several buildings in this corridor carry multiple tenancies on shared water and drainage. That means a blockage caused by one unit surfaces in another, and that isolating one tenancy for repair can take water off several. Before any work starts in a multi-tenant building, we map which valve serves which unit. It sounds obvious. It is skipped constantly, and the consequence is a neighbouring business losing water without warning.
Covering Christiana
Roughly five miles east of Newark, in the 19702 and 19713 ZIP codes, covering the mall and hospital corridor and the surrounding residential streets. Commercial work is scheduled outside trading hours as standard. Adjacent Bear and Glasgow are the same run for us.
Plumbing questions from Christiana homeowners
Almost certainly, if you prepare food. Sewer authorities require food service establishments to intercept fats, oils and grease before they reach the public system, because grease is what causes main line blockages downstream. Requirements cover sizing, siting and documented cleaning intervals, and they are enforced through inspection.
Sizing is not guesswork — it is calculated from fixture capacity and flow. An undersized unit passes grease straight through and gives you the blockages anyway, plus a compliance problem. Confirm current requirements with New Castle County and your municipality before fit-out, because getting this wrong at design stage is expensive to correct later.
A backflow preventer stops water in your building being pushed or siphoned back into the public supply — which matters enormously where a premises handles chemicals, has a boiler loop, an irrigation system, a fire suppression system or medical equipment. Water suppliers generally require these devices on commercial connections and require them to be tested periodically by a certified tester, with results filed.
If you occupy commercial space in the Christiana corridor, you very likely have one, and it very likely has a testing obligation attached. Your landlord may or may not be handling it — worth confirming rather than assuming, because the liability usually follows the water account.
Yes, and for most commercial work in this corridor that is the only sensible way to do it. Shutting water to a restaurant at lunchtime or a retail unit on a Saturday costs the tenant far more than the plumbing does.
We schedule commercial work outside trading hours by default and plan the isolation so the smallest possible part of the building loses service. For a multi-tenant building that also means identifying which valve serves which unit before starting, rather than discovering it by shutting off the wrong one.