I recently found out that my water main under the driveway, of course, was leaking. I paid to have someone detect where the leak was and jack hammered and dug to get to the leak. I found the leak on a 1 foot piece of black ABS Sch 40 piping connected to white PVC Sch 40 pipe on each side. What are the reasons why this section leaked? I heard that there is no glue that can join the two different types of material and that Black ABS pipe is typically used for sewer lines. Is that true?

-Mark

Mark, you are correct, black ABS pipe is not for use as a water main (it’s not made to withstand much pressure), it should only be used as drain and sewer piping (carries away wastewater under no pressure). Most plumbing codes don’t permit ABS pipe to be glued to PVC, though you should check with your local inspector. You should use a transition coupling, a neoprene rubber sleeve that fits over the end of each pipe. It’s then held tightly in place with a stainless steel metal jacket and clamps. Couplings are labeled to show which type of pipe each end can be attached to. Perhaps this ABS pipe was used as a sleeve and your water pipe was actually inside, it is very unusual that ABS pipe was used as a water service.

-Brian

We have a 2 story building in reconstruction (due to fire) with the slab and underground utilities as the starting scenario.  We need to pass city code pressure test of waste system before framing. We are struggling resolving leaks in the 6 inch waste line system under the slab.  The ABS piping system includes Ys, 90s, couplers, and straight pipe sections.  What do you see as options for inner wall repairs at all the sections?  Is there a lining process recommended here?  Other method or process to consider?  Is there a compound or solution we can add with or without water to seal and flush through the system without upsetting authorities or agencies here in CA?

-Tom

Tom, I would recommend sock lining: a felt sock pulled through an existing pipe and then inflated/expanded to fill the width of the old pipe. The sock cures in place and you have a new pipe inside of your old one. I would recommend contacting a reputable trenchless technologies company that offers sock lining services.

-Brian

I’m wondering if ABS pipes will leach chemicals into water or soil if they are in contact with them for awhile (i.e a month) and if these chemicals will react with nitrate, ammonia and/or phosphate (or nitrogen and phosphorus in general). The pipe and soil will be kept at room temperature or colder and distilled water will be used, although the water will pick up other compounds as it passes through the soil. This is for a master’s project studying leaching of fertilizer through soil samples taken with sections of ABS pipe.

–Miranda

Miranda, There is a possibility of leaching small amounts of styrene monomer from ABS (Acrylonitrile Butadiene Styrene) when in contact with water for a long time, but I would expect it to be at very low levels, so unlikely to interfere with the fertilizers. To get the the least amount of leaching try to get ABS pipe that meets ANSI/NSF Standard 61.

-Dr. Dave