Building Principles: The Ins and Outs of Pipe

Richard “Rick” Stryker, PE

“Appearances can be deceiving.” This old expression is as true today as it was when it was coined. In fact, things that look very simple or most ordinary can be much more complex than we ever imagined. At camp, there’s no place where that’s truer than in facilities where critical systems serve crucial health and sanitary needs. Pipes are simply special channels to convey a fluid, usually underground. At camp, that can be storm water, potable water, wastewater, or even propane. Almost without exception, pipes are intended to keep the fluid inside the pipe separate from the environment. Two common exceptions are septic drain fields that let their contents out and foundation drains that let groundwater in. By and large, though, pipes are supposed to keep their stuff in and the material around them out.

But if everything going on is underground, why should anyone care if pipes leak? Let’s consider all three systems: potable water, storm water, and sewage. First, leaky water pipes are more than a waste of water. It takes electricity (that costs money to generate or to buy) to build and maintain pressure in a water distribution system. And more importantly, leaky pipes cause contamination. A fresh-water system is intended to convey potable water from its source and treatment to the point of use. Where water can get out of the pipe, bacteria and other contaminants can get in. Water moving past a crack or hole in the pipe can draw unclean groundwater into the system. That’s why boaters take the plug out of the hull and run at high speed (it sucks the water out).

In case you’re thinking that this doesn’t apply to you because all of your water line is laying on the ground, I should tell you that the most serious case of tap water contamination I have professionally encountered involved just such a system. This particular camp used hundreds of feet of black two-inch polyethylene pipe joined together with barbed fittings and hose clamps. They were cited by the health department for bacterial contamination. No matter how much chlorine the camp pumped into the system, they just couldn’t pass the test. It so happened that one of those barbed-fitting joints was laying in a puddle of standing water full of mosquitoes and an animal carcass. When water moved through the pipe, the leaky barbed-fitting joint was sucking in that bacterial soup. It can happen above or below ground, so a watertight pipe network is not optional unless you’re trying to make your staff and guests sick.

As for storm water culverts, ground water flowing into the pipe at joints or holes carries bits of soil with it. Over time, the road subsides and eventually collapses. Finally, leaky sewer systems not only allow unsanitary waste to escape, but collect and convey ground and rain water to systems that were designed, built, and operated to receive a specific amount of fluid. These sorts of systems are quickly overwhelmed by inflow, and are reduced to sloppy, ineffective messes due to increased volume. It’s plain that any sort of leaky pipes are a problem wherever they happen.

So leaks are bad. But how do you know if there’s a leak, and then how do you find it? Again, we’ll pull apart the question by looking at the different types of pipe systems, starting this time with the storm water system. Most camps don’t have an extensive storm water piping network, so generally speaking, the focus is on relatively short runs of culvert pipe. As mentioned earlier, the most obvious symptom of storm pipe trouble is subsidence above the culvert. A growing pothole directly atop the pipe is a sure sign of a leaking culvert because material that had been around the pipe is escaping with the storm water. As the material on top thins out, vehicles transmit more and more of their wheel weight directly to the pipe, which (at best) flexes, further loosening more material around it. Galvanized metal pipes may bend instead of flexing, weakening the rust- inhibiting coating and accelerating the deterioration and leak problems. The solution is simple: Dig it up and replace it! If the existing pipe often flows full with either the en- trance or exit submerged, you should seriously consider installing a larger pipe. Regular readers will tell you that the January/ February 2012 Building Principles explained all about how to do that right!

Pressure water systems are almost as easy as storm water systems to check for leaks, but finding the leak may prove more difficult. Unless you have a gusher spewing up from the ground, you’ll have to do a little detective work. Because it takes some time, undivided attention, and helpers, this is a great procedure to follow when you open camp in the spring and close it in the fall. You know that a water distribution system should operate under pressure, usually between 30 and 50 psi. Close all of the building valves, pressurize the system, and watch the gauge. If the pressure drops, water has escaped, and you have a leak . . . somewhere. By removing all of the buildings from consideration for leaks, you’ve already isolated the problem to just the distribution system. For that matter, if your well cycles on and off repeatedly, or if your booster pumps are running even in the dead of night, those are also symptoms of a leaky system (or a running toilet, drippy faucet, etc.). Systematically close valves along the main line of your system to find the run of pipe that is leaking. And though there won’t likely be a flashing arrow that says, “Leak here!” you’ll have narrowed your search.

You may be asking now, “Yeah, Mr. Smart Guy, but what if a valve is leaking?” The answer to that is also surprisingly simple: Spend $15 and get a mechanic’s stethoscope. Instead of having a little diaphragm on the end like a physician’s tool, a mechanic’s stethoscope has a solid rod. Just as if you were determining which lifter is bad in an automobile engine, place the end of the rod on a valve (handle or stem) and listen for the water rushing through. Replace it and repressurize the system until the system holds pressure. Like I said, it’s simple. Remember that I said nothing about “easy” or “cheap,” but if keeping camp in the hospitality business is what it’s all about, repairing your water leaks is a necessary bit of ongoing work. Leak detection in gravity (sewer) piping is an even more difficult and time-consuming exercise than in pressure pipes because fluid getting in is a sporadic, usually weather-related condition. Often the only symptom is when wastewater systems are inundated hours or even days after snow melts or a torrential rain. So it can be difficult to connect the cause (lots of water into leaky pipe) with the effect (flooded septic system or wastewater plant). A savvy facility manager or caretaker is paying attention to the facility and makes those connections over time, but the trick is recognizing that while it may be “the way things are,” it doesn’t have to be — and it’s costing big bucks in the long run. In general, there are two ways that gravity pipe is checked for leaks. The simplest approach follows the water pressure method described earlier, only in this case, air instead of water pressurizes the line through an airtight plug. Each leg of pipe should hold 5 psi for an hour or more. If it doesn’t and the plugs are sealing the pipe correctly, there’s a leak in the pipe. Again, that doesn’t tell you exactly where the leak is, but you’ve narrowed it to a specific run of pipe. In the same way, blowing smoke into the collection system may identify connections that nobody even knows about. Gutter downspouts are huge culprits in the problem. Incidentally, the low-pressure air technique is the very same method I specify for contractors to demonstrate that new sewer lines are tight before they’re backfilled, and smoke testing is very common as well for existing systems. They work! For many existing systems, though, there aren’t enough manholes or cleanouts for access to the system. In those cases, a high-tech solution like closed circuit TV may be the only answer to finding where pipes are crushed, leaking, have joints full of roots, etc.

It should be no surprise to learn that leak detection is big business in the municipal water and wastewater world, and no camps that I know have the resources or interest to invest in the technology to make it easy. Among a half dozen other reasons, that’s why we recommend that camps join and become active in trade groups like the Rural Water Association (RWA). Each state has a sister organization and there are usually regional chapters with members who are full-time operators with their systems. There is a deep well of experience and knowledge upon which members can draw. Further, many municipal systems or cooperative units of the RWA have purchased leak- detection equipment that would be too expensive for any single organization to afford. As a fellow member, they may be able to help you find your leaks with their equipment and skills.

Stewardship of all of camp’s resources, including time and money, is not optional. Active management, care, and maintenance of the invisible infrastructure is every bit as important as tending the above-ground things. Make the investment in time and money to ensure that the critical systems that support all of your great programs are healthy as well.

Rick Stryker is a professional engineer with a particular passion for helping camps with infrastructure, planning, and regulatory issues. He can always be reached at campfc@ptd.net or 570.828.4004.
 

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