Plumbing in Cornwall, PA

What the iron era left behind

Cornwall is unusual in this county in that you can date most of the housing from the furnace. It ran from 1742 until 1883, and the village around it was built for the people who worked there. Cornwall Iron Furnace is a National Historic Landmark now, and the borough around it, ZIP 17016, carries housing stock of a similar age.

What that does not tell you is what your pipes are made of. Housing here spans a wide range of ages, and plumbing has been added and replaced in sections throughout. The only reliable answer for a given property is to look at the pipe, which takes about a minute and is worth doing before any work is planned.

What that produces

Mixed materials in one line. Galvanized into copper into plastic, sometimes within a few feet. Where dissimilar metals meet without the right fitting, the joint corrodes from the inside and fails before anything either side of it does.

Runs that are not where you would put them. Plumbing added to an existing masonry building goes where it can, not where it should. Chasing a leak through stone is slow, and opening the wrong section is slow and messy, so locating properly first saves a second opening.

Supply that has closed up. Galvanized steel rusts inward. Pressure fades over years, gradually enough that households stop noticing until a second faucet opens and the shower drops to a trickle.

The service line question

Cornwall is on City of Lebanon Authority water, and that puts it on one side of a split that matters. In the parts of this county supplied by Pennsylvania American Water, the utility replaces the customer-owned half of a lead service line under its own program. On CoLA supply there is no equivalent published program, so that run is the owner’s to arrange.

If a letter has arrived about lead or unknown pipe material, the full guide sets out who handles each half, supplier by supplier, and includes a check you can do yourself in about a minute with a coin and a magnet.

A proposed interconnect, and why it is being discussed carefully

There is a proposal under discussion for a three-way water interconnect between Cornwall Borough, the West Cornwall Township Municipal Authority and the City of Lebanon Authority. It is a proposal, not a scheduled change, and it is worth describing as one.

The interesting part for anyone with plumbing in the borough is why CoLA staff have raised caution about it. The two sources are chemically unalike: CoLA’s surface water runs at a high pH with low alkalinity, while the West Cornwall well water is the reverse, low pH with high alkalinity. Mixing supplies of different chemistry is not a simple matter of blending, because the scale layer inside old pipework forms in response to the water that has been running through it. Change the water and that layer can start behaving differently.

None of which is a reason for alarm today. It is a reason to pay attention if it goes ahead, and to say something if your water changes in appearance, taste or pressure afterwards, particularly in a house on original pipework.

Outside the borough

Out toward Rexmont and the farmland beyond, properties are frequently on private wells. That replaces the service line question with a water quality one, and the issue is usually corrosivity rather than hardness. Corrosive water dissolves metal out of your own plumbing, which is what produces pinhole leaks in copper and blue-green staining around drains.