Template:305 CCAT Rainwater Upgrade

Background

The rainwater catchment system at Humboldt State University’s Campus Center for Appropriate Technology was created in 2008 and revamped by an Engineering 305 group in 2014. However, the rainwater catchment system is currently not in commission due to several factors such as overflow issues and tank cleanliness which means perhaps redesigning the system. In order to update the current system, it may mean resizing, labeling, gutter screens, testing, cleaning, and pumping parts. The Campus Center for Appropriate Technology is a learning center for students and community members to learn and share practices of sustainable living so it is valuable to showcase a rainwater catchment system. The rainwater catchment system will also allow for an emergency water source and decrease in a water bill for the Center.

Problem statement

The objective of this project is to recreate the rainwater catchment system through the use of recycled items and existing parts, in order to catch rainwater effectively.

Literature Review

Storage is usually the most expensive component of a rainwater system and often determines the type of filtration and pumping system. There are a variety of types of rainwater catchment systems available, ranging in quality and durability. The most common storage containers are large-scale plastic tanks, 55gallon barrels, and custom ferrocement tanks. Free-standing plastic tanks provide the least expensive means of rainwater storage, both in purchase cost and installation cost. Always be aware of soil compaction when finding a place for the storage container to be located. A large 1500 gallon rainwater tank was used at the CCAT water catchment system. It is apparent that the container is black. To prevent algae build up.(1)[[1]]

Conveyance

The conveyance system of a rainwater catchment is what brings the water from the roof or catchment system into the water storage tank. The parts of conveyance consist of gutters, piping, first flush, screens and filters. For the purpose of this literature review, the piping will be emphasized. Different materials can be used for piping. The inexpensive option of PVC piping will be used for this project. PVC is a very durable plastic that does will not leach or corrode from contact with water. An important aspect of using PVC is the diameter. Wider diameters will cost more, making the smallest diameter possible beneficial to reduce cost.

Screens

Once the rainwater runs off of the roof(catchment surface) it is caught in the gutters and gets redirected to the gutter drop( the spot where the gutter converges vertically). This is where the screen will be placed at a 45-degree angle, for easy maintenance and simple visual representation of how much debris has been accumulated, not to mention this is where most of the particulates will be caught. We chose to use chicken wire to catch the larger bits of sticks and twigs, and as the system continues flowing to the conveyance pipes. The second screen for this system will be placed right before the first flush, but this second screen will be made of finer mesh material so to ensure that all of the dirt will be extracted before entering the storage tank.

First Flush

Rainwater will pick up the majority of contaminants as it flows across your roof and into your collection tank. A first flush system is a solution to contamination by diverting the first water caught with debris and flushing out contaminants before it reaches your water storage unit. Bacteria mold and algae are the most common contaminants in a rainwater holding system so shaded containers which block sunlight help fight contamination. Closed containers also help avoid contamination by not letting in extra bacteria or mosquitos into the water storage unit.3. First, flush systems allow for less water harvested but cleaner water within the water storage unit. “diverting the first part of the rainstorm can reduce the incoming contamination by 90% while delivering 85% of the water as measured after the storage tank. Greater material removal is possible but with significant loss of water.”4. Two types of first flush methods are the tipping method and the floating ball method. The tipping method allows a bucket to fill with water and spill before filling the water storage unit. The floating ball method allows the first rain to fill the first flush unit until a floating ball closes up the first flush and allows the remaining water into the main water storage unit. A small borehole near the bottom of the first flush allows the first water to slowly drain. A removable cap in the first flush allows for cleaning contaminants compiled within the first flush. 5.

CCAT

CCAT has provided HSU students with hands on experience in sustainability since 1978. Through life in laboratories, classes, workshops, and tours CCAT supply its learners with knowledge and methods to live with less environmental impact. The student ran and funded program impressively uses less than five percent of the total energy consumption of the average American home, uses near zero waste, and leads in being one of the most success appropriate technology programs. Students that engage in CCAT’s will learn leadership and technical skills that will serve in expressing their creativity. In closing, CCAT’s goal is to serve the global community as a whole, sustainably. [[2]]

Labels and Signs

For a system to be successfully implemented, labels and signs are mandatory in aiding and directing users. Above all, the system is required to inform users if the water is potable or not clearly. In addition to obvious signs and labels, it is beneficial to attempt to set guiding signals when designing each rainwater catchment system. These guiding signals, or nudges, will allow users to use the system more accurately without being bombarded with overwhelming instructions. Examples of “nudges” including installing the first flush adjacent to a heavily trafficked pathway to encourage involvement and awareness. Point positive is an additional design that encourages users by guiding them in what to do, and not what to do. Signs that tell users what not to do may not be as successful as accurately placing certain parts of the system that serve your goal. In addition to nudges and point positive design, using common symbols are best used to make clear what the instructions are. For example, using a universal sign like a smiley face may better serve your user than writing instructions. Before making signs, make sure to produce low budget prototypes made out of cardboard and pen. Place the prototypes around the system and observe how users engage with the system without further instruction. Grafman, Lonny. To Catch The Rain. Humboldt State University Press 2017

Climate

Arcata, California receives 7 inches more than the national average of rainfall annually at 46 inches. Rainfall occurs roughly 20% of the year and has the average temperature of 65 degrees Fahrenheit. Roughly 175 days are considered sunny with a low average temperature of 41 degrees Fahrenheit. Arcata is considered a comfortable climate rating a 79 out of 100 on the Sperling’s comfort index. [[3]]


Proposed Budget

Project Evaluation Criteria

The following Criteria will be used to assess the success of this project. These criteria were chosen based on the suggestions of the project coordinator as well as the diligent students who are working on the catchment system. The scale (1-10) represents the importance level of meeting the constraint of each listed criteria.

Criteria Constraints Weight
(1-10)
Safety Meets or exceeds OSHA standards
10
Aesthetics Current aesthetic
7
Maintainability 1 year
8
Usability 10 foot radius of water usability
9
Sustainability 100% made up of reused materials
6
Water Catchment percent 95% caught to overflow
7
Cost CCAT budget 2018
10
Community access Anyone can access the water
9
Lifespan/ durability 5 years durability
10




Reference

1.) "RAINWATER STORAGE." Rainwater Harvesting - Storage. Accessed February 18, 2018. http://www.conservationtechnology.com/rainwater_storage.html.

2.) Srinivas, Hari. "An Introduction to Rainwater Harvesting." Accessed February 18, 2018. https://www.gdrc.org/uem/water/rainwater/introduction.html.

3.) Fryer, Julie. The Complete Guide to Water storage: how to use tanks, ponds, and other water storage for household and emergency use. Atlanta Publishing Group Inc. 2012

4.) Martinson D.B, Thomas T.H. Quantifying the First-Flush Phenomenon: Effects of First-Flush on Water Yield and Quality. Department of Civil Engineering, University of Portsmouth, Portland Building, Portland Street, Portsmouth, PO1 3AH, UK. 2009

5.) Grafman, Lonny. To Catch The Rain. Humboldt State University Press 2017

6.)https://ccat.humboldt.edu/content/about

7.) Grafman, Lonny. To Catch The Rain. Humboldt State University Press 2017

8.) [[4]]

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