Urban Survivalists

We are directly in the middle of our rainwater collection build. Our to do list includes:

• create first-flush system
• attach gutter downspout to subsequent first flush parts
• finish the roof washer and attach it to the barrel
• attach sillcock and related to the barrel
• put the barrel in place
• attach first-flush system to the house
• run a pipe from the first-flush to the roof washer
• sit back and enjoy the newly collected water

For this week, we will be building the first-flush system, attaching the roof washer to the barrel, and adding the hose/sillcock to the barrel outflow.

Building the first-flush system:

We had originally planned to use two 5gal buckets attached together for the first-flush system. However, we forgot that the ten gallon capacity for first-flush systems suggested by our local code was for an entire roof, and we are only collecting water from a portion if our roof as a trial. This means that we don’t need a ten gallon capacity for this first-flush system. We opted to use a piece of 4inch inside diameter ABS pipe instead. Later posts will see the addition of an appropriately sized first flush system to compensate for flow from the entire roof.

The plan was to use a pipe cap for the end of the first-flush system. There would be a small hole in the pipe cap to allow water to slowly leak out over a period of time. The time is determined by the volume of the pipe, in our case this is2.55gal, which gives us several hours with our size hole. Placed over this hole would be a screen or mesh to keep larger debris from clogging it and necessitating cleaning. A pipe coming out of the top first-flush pipe would lead to the roof washer. Basic operation: rain event happens, water fills first-flush up to point discharge point, water discharges into  roof washer and then begins running through it and into the barrel, hole in bottom of first-flush slowly drains the water so that, by the next rain event, the first-flush is empty.

To start the construction, we bought a pipe cap for the 4″ pipe. We used a 1″ diameter pipe cut to a length of about one inch as a stand off in the pipe cap.This stand off was then glued to the bottom of the inside of the pipe cap. The mosquito screen was then cut and fit into the bottom of the pipe cap to cover the pipe stand standoff. A hole was drilled in the bottom of the pipe cap in the middle of the pipe stand. The purpose of all this is so that sediment build up and clogging is prevented to some extent. Next, the pipe was glued onto the pipe cap using standard ABS cement.

Time will tell how well this setup works. We found it in the Roof Water Harvesting booklet listed in our links & resources section.  They cautioned that it had a tendency to fill up with sludge and block the outlet hole. Since were making this first-flush system easily detachable, we figure that cleaning shouldn’t be too large a burden especially if we can increase the amount of time between cleaning by placing a screen above the outlet. We may also find that the drain time is too fast, but with the amount of water we get in our area, this shouldn’t be a problem.

Creating the barrel outflow with hose/sillcock combo:

The outflow of the barrel, as we’ve mentioned before, needs to allow us to take water from the top of the tank to avoid sucking out the sediments. To do this, we used a threaded/barbed adapter, a sillcock, and a 4ft piece of clear vinyl tubing. The sillcock screws onto the adapter with PTFE thread seal tape, the hose gets pushed into the inside of the barbed end of the adapter, and the whole assembly gets pushed through a hole in the wall of the barrel with the sillcock on the outside and the vinyl hose on the inside. Sounds simple…hehe, yeah right!

Here’s  how things actually went down. First we threaded the sillcock onto the adapter with plenty of PTFE tape and used PVC  cement to glue in the vinyl hose to the other end. Leaving this to dry, we drilled a 5/8in hole three inches from the bottom of the barrel for the barrel outflow. We then used a long piece of wire threaded down from the bung hole in the top to the newly drilled outflow hole. Once the sillcock/adapter/hose combo was dry, we drilled a small hole in the end of the vinyl hose furthest form the sillcock and looped the wire through this so that we could pull the hose through the outlet hole and up through the bung hole. Once we had accomplished this feat–none to easy as fishing a wire across a 3.5ft gap is fiddly–we found that the 5/8in hole just wasn’t big enough by about  1mm all around. Back out came the hose and wire so that we could cut on the hole with a utility knife in an effort to widen it. Three or four attempts later, the sillcock/adapter/hose combo finally slammed into place with a nice helping of caulking to prevent any slow leaks. The seating of the sillcock assembly was accomplished by our friend Eric. He’s so handy for brute force tasks…hehe. Such a simple little guy!

We attached a small float to the end of the tube using stainless steal welding wire (.030in). We were forced to buy a bottle of water from the hardware store to act as a float but we figure the $0.99 was well spent as our fish got the water, not us. To the same hole in the vinyl hose but on another piece of wire, a rock was attached so that the hose would always be below the surface of the water. There was some discussion about whether this rock would be too heavy for the float and render the whole exercise pointless. Stan believes the float has more than enough lifting power but Eric and Pam are skeptical at best. Time will tell.

Attaching roof washer outflow to barrel inflow on-site:

We are using 1″ PVC pipe to connect the roof washer outflow to the inflow of the barrel. The pipes extend almost to the bottom of the barrel and have 90 degree bends on the end in order to deflect the incoming water away from the bottom of the barrel so as to avoid stirring up debris. The inflow pipes connect to the pipe sections built into the roof washer in a permanent fashion. This is, frankly, non-optimal in our situation but we didn’t see any quick/easy/cheap alternatives so this is what we went with in our trial system.

The construction was simple and straight forward but the layout took a bit of measuring and thinking. The two pipes come out of the roof washer at an angle so they get further apart the further you get from the roof washer. This mean that the pipes needed to enter the barrel through the bung hole fairly soon after leaving the roof washer. However, since we could not cut the pipes far enough back to allow the inlet pipes to go through the bung hole together due to the width requirements of the 90 degree elbow fittings, the pipes had to be cut at different lengths. This allowed room for the 90 degree elbows but then necessitated the inlet pipes be angled toward each other so that they crossed as they went through the bung hole. The pictures will make this more clear.

We measured and eyeballed things into an initial alignment before applying any PVC cement. Once we figured we had things lined up, we made some nice sharpie marks on the pipes and fittings so that we could get them back to the place they needed to go when we applied the PVC cement. After this, things went very quickly.

The 90 degree elbows were glued onto the outlet pipes of the roof washer first. Then, two length of PVC pipe were cut to the appropriate length for inlets–about 36 inches–and two more 90 degree elbows were attached to these. The two inlet pipes were not connected to the roof washer outlet pipes until the barrel was in place and we had a make-shift stand for the roof washer. Once things were on site and lined up, we applied PVC cement to the other end of the inlet pipes and the 90 degree elbows on the roof washer and attached the two with the inlet pipes crossing through the bung hole. This last operation required the roof washer to be lifted up by our helpful friend, Eric. Thanks again Eric!

That’s it for this week. Next week we will attach the first-flush system to the house and route pipe from it to the roof washer. That will complete our trial rainwater collection system. After that, we can begin collecting data on it and refactoring the design to make it faster/cheaper/better. We’ve already purchased two more 65gal barrels from the hardware store. We want to extend this system as soon as possible so that we can begin reaping the benefits of the water falling from the sky.

Be safe and sustainable!

P&S