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CCAT rainwater catchment solar pump system/OM

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Introduction[edit]

Figure 1: Aerial photograph of the system

The goal of the operation and maintenance plan for this system in 2019 is to ensure the system fulfills its role in CCAT. The plan is based off the concept of CCAT as a learning laboratory for appropriate technology, meaning that every project must be (a) appropriate, (b) educational, and (c) adaptive. In our conception of appropriate, we require the system to fulfill the appropriate technology (AT) field-specific meaning and align with CCAT’s mission of helping users to ‘live lightly on the land.,’ But more, it must be appropriate for the specific circumstances of CCAT, in which it must be flexible so future students can adjust or use the system;, it must be educational for CCAT visitors, and it must fulfill its purpose in CCAT. In terms of operations and maintenance (O&M), these mandates mean that the O&M plan must be straightforward, relatively low maintenance, accessible, and carried through multiple CCAT generations.

An overview of the plan is that the system is interacted with in summer, otherwise, the operation of the system is passive - it can catch, pump, and store water by itself. The maintenance plan has weekly, monthly, and yearly components. The most important part of the maintenance plan is the annual cleaning, which should involve all Co-Directors as it is the main mechanism for the transfer of knowledge across CCAT generations. One of the most critical parts of the plan is information accessibility, so there will be user-friendly documents on-site (see File:RCSP-fieldmanual.pdf and online (see File:Apendix c.pdf).

System Operations[edit]

Figure 2: CCAT Rainwater Catchment Solar Pump system overview 2019

The system is used by CCAT in the dry months, and in the wet months, it can operate passively. More information on the system operation can be found on File:Ccat RCSP redesign supply 2019.pdf. It is easiest to understand the system as if it consists of two separate parts: the wet side and the electric side. Essentially, the system catches, pumps, and stores rainwater to be used later (see Figure 2). Rain is caught on the roof, falls into the gutter, flows through the filter then over/into the first flush, and into the bottom storage tank system. The solar panel provides power to the pump, which pushes water up the hill to the upper tank when it is sunny. Opening the valve by the base of the solar panel allows water to flow out of the upper storage tank. The water from the upper tank gets delivered to the delivery hose which is near the pickle barrels in the bottom.

On the wet side of the system, water enters the system via the catchment area which is the tool shed roof. After getting collected in the roof the rainwater passes through the gutter which is also called the conveyance. The roof and conveyance are angled/tilted so that the water is conveyed with just the force of gravity. After passing through the conveyance the rainwater passes through the screen where the large debris, leaves and other particles are filtered out. Following that, the first few minutes of rainfall or the first few gallons of the rainfall enter the first flush. This is the dirtiest part of the rainfall which is not suitable for irrigation purposes. Once the first flush is full, water can pass over the top of the first flush and enter the three storage tanks which are next to the toolshed. The three storage tanks consist of one 264 gallon IBC tank and two 100 gallon pickle barrel tanks. The overflow pipe above the IBC tank helps drain water if the volume of rainfall is beyond the tank capacity. The water which is stored in the group of tans gets drawn by the solar water surface pump. The pump is powered by a solar panel located above it. The pump delivers the water to a 264 gallon tank which is situated up the hill. There are two points at which users can access the water. One of the outlets is attached to the hillside tank with a T connection. The other point is located near the base of the solar panel, where a hose can be screwed onto the pipe. Both spigots are connected to the upper tank. To use this water, users can connect a hose to the spigot head near the base of the solar panel or on the hillside, then open the appropriate valve. Water should flow.

On the electrical side of the system, the solar panel powers the pump, but can be turned off by a water level sensor if there is not much water in the lower tanks. On a sunny day, the panel is in direct sunlight for less than 5 hours, usually from about 11 or 12 AM to 3 or 4 PM. During these hours, the 18 V panel can provide enough power for the 24 V pump to pump water up the hill to another 264 gallon tank(approximately 26 feet higher in elevation than the bottom tanks). The pump is a self-priming diaphragm pump, meaning that it increases its internal volume to pull water in from the inlet, then closes that valve and decreases its internal volume, pushing water out the exit (imagine a heart). The electrical side of the system is wired so that the pump can be disconnected from the panel via a water-level sensor located inside the IBC tank below the overflow pipe.

Operation[edit]

System operation is mostly automatic. If you want to get water from the system, attach a hose at the connection point near the base of the panel. To water the food forest with the drip irrigation system, see the RCSP drip irrigation page[1]. If you run into issues, see the Troubleshooting Manual at File:Apendix c.pdf.

There are two main ways to use the water in the system. You can water the food forest through the drip irrigation lines by turning the lever controlling the valve connected to the black hose (see [[CCAT_rainwater_catchment_drip_irrigation_system/OM|RCSP drip irrigation page]). Or you can get water by attaching a hose to the other outlet, then turning the lever for that valve.

If water does not come out, check the water level in the top tank. If there is water in the top tank, but water is not coming out, check the troubleshooting manual. If there is no water in the top tank, you will not be able to get water at either of these connection points.

Operation
ImageStep
Picture of the main hose connection in the CCAT RCSP system Step 1 : Attach a hose to the open hole. When you turn the valve, water should flow.
Picture of the base of a tree with a soil moisture sensor Step 1: When you turn the valve attached to the black hose (the mainline for the drip irrigation system) water should flow through the drip irrigation system and water the food forest. See the drip irrigation page at CCAT rainwater catchment drip irrigation system/OM.


Maintenance[edit]

More information on system maintenance and troubleshooting can be found on File:Ccat RCSP o&m supply.pdf.

Schedule[edit]

Most of the maintenance tasks can be completed by anyone, there is no skill threshold. However, we recommend all Co-Directors participate in the annual cleaning because it will be a good way to transfer knowledge and make sure everyone understands the system. Please see the how-to guides below the schedule for further information about conducting maintenance tasks.

Weekly
  • Visual Inspection
Monthly
  • Clean Gutter (conveyance)
  • Clean Screen
  • Clean Solar Panels
Yearly
  • Flush and Scrub whole system. The ideal time to do this is when the system has no water in it at the end of the dry season (September or October). All CCAT Co-Directors should participate because this cleaning is one of the best ways to make sure everyone understands the system.
  • Check Water Quality (contract with a class or send to a local laboratory)

Instructions[edit]

Please see below for further information on how to complete the regular maintenance tasks. If a problem arises that requires immediate maintenance, check the trouble-shooting manual or other attached documentation.

Visual Inspection
ImageStep
Elevation next to the tool shed Step 1 : Visually inspect each system component, following the path of the water. Look for holes, breaks, misalignment, or other leaks. Take note of the water level in the tanks (full, half full, empty). If it rained last week, you should expect the water level in the lower tanks to rise, unless they were already full or unless a lot of water was pumped up to the top tank. Listen for a hum coming from the pump if it is in operation (sunny, and there is water that can be pumped uphill)
A view of the path looking up from the solar panel Step 2 : Walk up the path toward the top tank. As you walk up the path, look for leaks in the black pipes.
The top tank in the system Step 3 : Visually inspect the upper tank and the pipes leading into and out of the tank. Take note of the water level. If it was sunny last week, you should expect the water level in the top tank to rise unless there was no water in the bottom tanks or if the top tank was already full.
Clean Screen
ImageStep
Picture of the screen under the gutter Step 1: Remove debris from the screen. Next, take off the screen using the two tabs on the lower corners. Do not try to take the screen out of its frame.
Picture of the screen frame separate from the funnel Step 2: Scrub inside the funnel. If some debris have clung to the screen, you can get them off now.
Clean Gutter (conveyance)
ImageStep
Picture of the roof overhanging the gutter Step 1: Look at the debris build-up above the gutter. If you can remove loose leaf litter and debris, do so. Some debris in the gutter is okay, but if there is enough debris to cause a blockage, please remove it. You will have to cut the zip ties holding the loose net to the top of the gutter, and then replace the zip ties once you have removed the debris. In general, if the blockage isn't large, don't bother to remove the net, just lift debris off the top of the net with your hands. The net will be removed once a year and the gutter will be scrubbed out at that point.
Clean Solar Panel
ImageStep
Picture of the solar panel being cleaned Step 1: Use biodegradable soap, such as Dr. Bronner, mix with warm water, and scrub the solar panel surface with a soft cloth. You do not want to scratch the surface of the solar panel or use a soap that will leave a residue.
Clean and Flush the system
ImageStep
Picture of the first flush pipe being detached from the surrounding pipes Step 1: Wash and scrub the gutter and pipes
  1. Detach the pipes that you can and spray them out.
  2. Now is a good time to detach the loose net over the gutter and clean the gutter thoroughly using water and biodegradable soap. Make sure the first flush is as empty as possible when you are done.
Detached the pump and storage pipe connection to flush Step 2: Wash the bottom storage tanks

Wash and Spray the inside of the tanks and let the water drain out of the storage by opening the pipe connection between the pump and bottom storage system as shown in the bottom left yellow box in the picture. A long scrub brush is recommended to clean the inside of the tank.

loosen hose clamp Step 3: Wash the top tank

Loosen the hose clamp shown in the picture, using a screwdriver, and open the tank's valve to flush the system. A long scrub brush is recommended to clean the inside of the tank.