Anyone own a property with asbestos cement (AC) sewer lines? Or are familiar with them?
I’m looking at a property with majority of the lines made of this material. Just wondering if anyone has an opinion on this type of material good, bad or otherwise.
Thanks,
Robbie
AC pipe was pretty popular from 1950 to 1970. I operate two systems that have Ac pipe for both the sewer and drinking water 6 and 8 inch pipe. Its about 25000 ft of pipe. Ac pipe’s main weakness is cracking. If the pipe was not bedded in sand at least 12 inches under and 18 inches over it can be pretty stress prone especially sewer line since they are not under pressure. Drinking Water lines actually do better because water pressures keeps the pipe from collapsing. If the ground has lots of boulders or cobble and the pipe was not bedded correctly it will crack all over the place and leak like a sieve. On 20,000 feet of drinking water line I average 1 leak ever 2 years. However on just 5000 feet of sewer built 1970ish my wet weather flow is 300 % of my dry weather flow. In other words its time for new pipe. The video log pretty much say cracks and roots all over the place.
Ac has its own set of issues when working on it. Hazardous material and OSHA rules. Over 12" piece being removed must be tripple wrapped in 3mil plastic and taken to approved site to recieve it. Material must be wetted and no power tools used that may make it friable. Dust mask… every jurisdiction has it own level of enforcement that they do with federal OSHA rules. The asbestos is contained in the cement so it is low risk as far as asbestos goes but still hazardous and OSHA rules apply
Dont even think of not doing a video inspection of the collections pipes. Video then you will know. Maybe they put in thicker pipe and bedded it right then it is a pretty good product but dont count on it.
The two systems im talking about are in forests and have cobble and boulders up to the size of a house. Pipes have little to no bedding.
Phillip
Thanks Phillip. I’m planning to tv the lines.
There’s really no way to measure the infiltration in these lines during a rain event or wet weather, as you mentioned, except maybe to take a measurement at a particular manhole. To compare against dry weather, correct? Or how have you been able to determine a 300% increase during wet weather?
We have a package plant and measure treated effluent leaving it. Effluent goes through a weir and we have an ultrasonic level flow meter at the weir. We use a data logger that reads the output on the flow meter a logs it. We have a real tight reading on the flow. Flow varies so much by hour through out the day you really need a 24 hour window to measure it. Does the ac pipe just collect it for the city system or does it get treated onsite?
Most of the lines connect straight to the city’s system. But apparently there are about 20 lots that sewer runs to a lift station that then discharges to city’s system. It’s a large park of about 200 spaces, 135 occupied.