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Background

Humboldt State University’s Campus Center for Appropriate Technology (CCAT) was founded in 1978, a student run home maintained and run in a sustainable fashion, by the students of Humboldt State and members of the surrounding community. CCAT incorporates a wide variety of Appropriate Technologies. CCAT located near the redwood forest of Arcata, houses three full time students and employs 18 students part time.

Problem statement

CCAT is in need of a more convenient and efficient rainwater catchment system and usage of collected water. Water pressure is also lower than expected. A current system is in place and collects a large amount of water, being used for drip irrigation and is severely under utilized. The CCAT house has relatively new metal roofs and rain gutters (2009), which can’t be altered so improvements must be made to the tank itself, inlets, or outlets.

Project Evaluation Criteria

The following Criteria will be used to assess the success of this project. These criteria were chosen based on the needs of CCAT as well as the student working to improve the catchment system. The scale (1-10) represents the importance level of meeting the constraint of each listed criteria.

Criteria Constraints Weight
(1-10)
Budget Project improvements have ample funding.
1
Educational Aspect Currently serves as educational with a sign that explains rainwater catchment and its benefits. (sign can be better located)
4
Maintainability Must be easy to clean the filter and remove debris, no more than 1 hour of maintenance per month. (Current filter rarely gets cleaned, and a more self cleaning filter would serve well.)
6
Aesthetics Changes must be pleasing to the eye and look professional. (Current conditions of piping from gutter, release valve, as well as filtration can be improved upon.
6
Usability Must sufficiently water the garden on site, soon to be terraced hill side, and have the ability to be used elsewhere. (with use of hose attachment) High turnover rate in staff means the system directions need to be visibly apparent, or none needed to use. A simple design is key.
9
Functionality Successfully captures and stores rainwater, is able to have enough water pressure in order to divert water from tank to a possible uphill location.
10

Literature Review

This is a review of the available literature pertinent to the comprehensive rainwater catchment system at CCAT.

Rainwater Catchment basics - Overview

Rainwater catchment uses water runoff, often by rooftops, in order to collect and store water for later use. Most widely used in places where water is not centralized. This technique of water catchment uses the water from a surface passing through a downspout to a filtration system. The filtration is usually composed of a strainer or mesh that collects large debris and keeps it from entering the system. The strainer must be cleaned periodically so that it is not clogged. In some larger models the water then is funneled to a first flush system in which debris is dropped out of the water that collects in the tank, this allows finer particulate matter from the system to be purified before entering a holding tank. Once the first flush is full the water is diverted to the main tank where it is kept until use. This tank is equipped with a spout or way to get the water to its intended location for use, as well as an overflow outlet so that the system does not back up. Over time the tank must be maintained and cleaned in order to have a properly working system. Water quality can be tested and is often improved with the use of a bottom bio-layer which can form naturally in the bottom of the tank. [1]

CCAT Rainwater concerns

Since the rainwater catchment system is already up and running at CCAT, the problems in focus are those moving forward with the improvement of the rainwater tank. Concerns topping the priority list include allocation of rainwater in the surrounding area of CCAT, gutter method of collection, pressure of water from the tank, and export water valve. .[2]

Types of Rainwater Catchment

There are multiple types of rainwater catchment systems available, ranging in price and use practicality. The most common types include rainwater barrels, multiple rainwater barrels, and large scale tanks. [3]

Single Barrel Catchment

Single barrel catchment is a relatively simple method that utilizes a roof with gutters and under any downspout a single barrel is placed to collect water. The barrel can be designed with a simple top filter to catch any varying level of sizable debris, however this method lacks the luxuries of the larger catchment systems. Unlike other systems, this has no settling tank or first flush for particulate matter to settle out of the stored water. This system has a valve in which water can be gathered from, as well as a overflow spout where excess water can flow freely. [4],

Multiple Barrel Catchment

Multiple barrel catchment is also a relatively simple system in which, like the single barrel catchment, a barrel is placed below a downspout to collect water however multiple barrels, depending on the desired amount of water are connected in a system using PVC piping near the bottom of the barrels. This allows the barrels to fill and drain at the same rate. This system also includes a valve on one or multiple barrels in which a hose or appliance can be attached and diverted to a desired location. This method also can use a filter to catch debris, multiple tanks also act as a settling tank, where one tank collects a majority of particulate matter leaving those further away from initial catch barrel cleaner.[5],

Rainwater Tank with First Flush

A large rainwater tank is often used in this system, in which water from a roof is diverted through a basic filtration system. This system usually consists of a mesh filter over a bucket which doubles as a sediment drop out or settling tank. After passing through this tank water heads through piping to a first flush system to further purify the water entering the holding tank. Particulate matter, if any settles here and does not continue to the holding tank. After the first flush is full, the water starts to fill the tank where it is stored until use. This system uses a valve to divert water via hose to its desired location. Water can be turned on and off through a multiple valve system in order to prevent leakage. This system can also use a motor in order to pressurize the water exiting the tank, or rely on the water wanting to exit the tank as pressure.[6],

Construction

The construction of an efficient catchment device and transport to the location of the 1500 gal store. This was first done by creating a downspout off of the lowest point on the gutter surrounding CCAT.

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Then a measurement of minimal slope to connect the existing 3"pipe leading to the tank, to the new downspout location, 19' from the current location. The bucket used was measured and then placed <1" below the new downspout to give the angle of 8 degree slope to get maximum water collection potential.

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The bucket was retrofitted with a 3.15" hole to hold the new pipe surrounded by a coupling, using a drill bit. The bucket was then measured at a 60 degree angle and cut in order to yield best self cleaning results in the given space. The Hole was fitted with a 3" PVC coupling and then filled with silicone glue and PVC cement to secure and waterproof the new catchment bucket below the downspout. A Distance of 11" from house wall was measured to the center of bottom of gutter, so a 2"x4" was cut to 2, 15" lengths in order to be secured to the decorative L braces, to support the 3" PCV pipe in line with the 8 degree pipe slope. (photo) The 3" PCV pipe was suspended from the gutter in line with the 8 degree slope. The braces were secured to the CCAT wall with 2.5" wood screws, in line to support the 3"PCV pipe at its desired 8 degree angle.

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The new pipe of 19' was conjoined at 10' using a 3" coupling. This was connected to the old pipe (going to the tank) using a 22 degree angle elbow. The pcv pipes were all joined (at every break) with PVC cement (photo) This was connected to the retrofitted catchment bucket, using PVC cement.(photo) 3" PCV was attached using plumbers tape (metal) to the 2 wood supports leading to the catchment bucket. (photo) The old downspout was removed and then sealed using a recycled piece of metal and gutter glue, cocking.(photo)

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Overflow

A male threaded fitting to male spa tube connect was inserted with plumbers tape to the threaded fitting.

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This was then matched other the other side of the 1" spa tubing, by a male spa connect to 1"PVC connect which was connected to the male spa tube connect with an o ring tightener. This was then connected to a 10'x1" PVC piece.

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The preexisting 4x4 support to the 3" PCV pipe was sanded using a belt sander and finished using a cedar wood finish in order to preserve the piece of timber, without buying a new one or a pressure treated piece of wood.

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Help:Images#Galleries and probably Template:How_to (e.g. Barrel O' Fun Worm Bin Instructions). 

Timeline

The following is a table of the tasks and dates the tasks were completed

Estimated Date Task Completed
3/20/14 Measurements taken 3/20/14
3/22/14 Blue prints drafted, system designed 3/22/14
3/22/14 Blueprints approved 3/25/14
3/23/14 Parts priced 3/26/14
3/26/14 Parts bought 3/28/14
3/28/14 construction of outflow complete 4/5/14
4/10/14 wood cut, stained 4/12/14
4/10/14 Bucket catch created 4/15/14
4/12/14 Old system disassembled 4/19/14
4/12/14 New L braces attached to 2x4's and mounted to CCAT wall 4/19/14
4/12/14 New 3" pipe mounted to old system 4/20/14
4/12/14 Bucket catch connected to pipe system 4/20/14
4/12/14 New Downspout put in 4/20/14
4/12/14 Old downspout removed and patched 4/20/14
4/12/14 System tested 5/2/14
4/12/14 System bucket retrofits 5/3/14

Costs

The materials needed in table below were bought by money donated by CCAT, the following were items that CCAT already owned and were not necessary to purchase; 2x4 wood piece, 1"x10" wood flat, silicone glue cocking, gutter cocking, wood screws, plumbers tape, sand paper, belt sander, wood and plastic saw, drill driver, Philips screw driver.

Quantity Material Source Cost ($) Total ($)
2 10'PCV Black 3"pipes ACE Hardware 20.00 40.00
1 3" 22degree elbow connect Ace Hardware 4.00 4.00
2 3" coupling Ace Hardware 3.50 7.00
4 Decorative support brace "L's" Ace Hardware 8.00 32.00
1 watertight threaded facet, 1" Ace Hardware 9.00 9.00
2 1" spa tubing Ace Hardware 1.90/ft 3.80
1 threaded tube insert 1" converter PVC Ace Hardware 2.50 2.50
1 10'x 1" PVC pipe, grey Ace Hardware 12.00 12.00
2 twist tight "O" clamps Ace Hardware 2.00 4.00
1 PVC clear cement 8oz Ace Hardware 6.00 6.00
1 Hensel's clear cedar finish 1Qt Ace Hardware 11.50 11.50
1 role plumbers tape Ace Hardware 2.00 2.00
1 male spa tube connect to female pvc 1" connect Ace Hardware 2.50 2.50
1 3'x3' 1/4" wire screen Ace Hardware 3.00 3.00
Total Cost $139.30

Operation

Operation is simple all it takes is the simple turn of 2 valves in order to let the water flow and then the directing of the outflow 1" PVC

Maintenance

This is a mostly self-sustaining system, which needs little work, but is detailed in the schedule.

Schedule

This is when to maintain what.

After first rain of season
  • Clean off catchment screen
  • Make sure first flush nozzle is 1/2 turn open
  • Inspect system for leaks or deterioration, patch with PVC cement where needed
Yearly
  • Introduce a chlorine to the water to keep water healthy and not a breeding ground for bacteria and pests such as mosquitoes

Instructions

Conclusion

Testing results

No leaks were detected in system when rain fell onto CCAT roof and traveled through system.

Discussion

Testing results indicated that the slope of the screen was not accurate, adjustment was made and now accumulation of debris seems to be minimal. As rain accumulated in gutter there were no leaks and water was caught by bucket and transported by 3"PCV to storage tank to where it is held until used. Overflow works well, directs water away from tank and kept original 1" hole size.

Lessons learned

Allow more time for mistakes to be made, such as varying types of PCV and PVC sized piping depending on if it is designed for plumbing. A project that seems small, may not be. Even if a project seems small, grab someone else to work with, it will help the process go smooth. Start as soon as the projects are given out instead of 3 weeks later.

Next steps

This project should be self sustaining for years to come, however spots of the house wall still need to be paint matched, where old L braces were previously located. The gutter patch needs to be textured and paint matched to draw attention from the current color difference. Also to improve flow more head is needed, which is impossible given the current conditions. The attachment of a pump will improve flow rate by roughly 30%.

Troubleshooting

Problem Suggestion
water is running not fully being captured by bucket clean the screen and or gutters of debris
Does not allow water to flow Make sure both valve closest to tank and that closest to garden are turned counter clockwise.
Water trickles instead of flows turn pump on

Team

...

References

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  1. Schiller, E.J. and B. G. Latham 1987. A Comparison of Commonly Used Hydrologic Design Methods for Rainwater Collectors, Water Resources Development, 3. .
  2. Another example of footnotes.
  3. This is an example of a named reference. You can use these named references to repeat citation content throughout the document.
  4. Dwayne Taylor, Jonathan . "Rainwater collection and distribution apparatus." United States Patents 1 (1998): 1-3. Print..
  5. Scilink. "Rainwater Harvesting." Rainwater Harvesting. N.p., n.d. Web. 7 Feb. 2014. <http://www.kidsfromkanata.ca/files/rainbarrels.html>..
  6. "Rainwater Harvesting." Wahaso Water Harvesting Solutions. N.p., n.d. Web. 6 Feb. 2014. <http://wahaso.com/rainwater_system.php>..
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