Laura Mercado Scool community project- INCI4056 UPRM

COMMUNITY PROJECT: LAURA MERCADO SCHOOL, SAN GERMAN, PUERTO RICO

Juan P. Arocho-Matos Elier Sánchez-Pérez David Santiago-Bonilla INCI 4056-090 Professor: Francisco Maldonado-Fortunet, PhD

AGENDA Introduction  Problem exposition  Activities  Design  Conclusions and recommendations 

INTRODUCTION

The Rosario Neighborhood is located in the City of San German, and it is primarily an agricultural region.  The Laura Mercado school is a junior-high and high school, attending students from Rosario and nearby neighborhoods of San German, Mayaguez and Maricao.  The school was intended to close by the State’s Department of Education, but the facility survived to be transformed in a specialized school in agriculture and with an eco-agricultural scope. 

PROBLEM EXPOSITION •

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The school was threatened to stop operations due to the low student enrollment.

Hey decided to specialize the school in ecoagriculture field.

The school has an approximate 3.05 acre land, where agriculture courses are given.

With the goal of been self-sustainable, the farm needs an irrigation system based on rainwater.

ACTIVITIES A field inspection was made.  A topography of the farm was taken with the use of satellite images.  We seek advice from agricultural engineering and irrigation systems experts to determine the water consumption of the plants.  Computer software were used to estimate the required amount of water.  Se utilizaron programas de computadoras para la estimación de cantidad agua requerida 

FIELD INSPECTION

TOPOGRAPHY

DESIGN To pursue the Laura Mercado school’s goal to become an eco-agricultural school, the LEED Green Associate Study Guide was used as reference.  This manual –made by the US Green Building Council- focuses a vision of the preservation of our resources and a better space and structural design. 

Among the considerations LEED has to classify a “green building”, the adequate use of the water resource is one of them.  Using the PRET (Puerto Rico Evapo Transpiration Estimation Computer Program), the necessary data was obtained to know tha amount of water the plants the school will harvest. 

COMPUTER PROGRAM USED 

PRET

DRIP IRRIGATION SYSTEM The system that was designed was for a drip irrigation system, because it has an efficiency of 90%.  The system minimize the water usage and fertilizers, because the water drops runs slowly to the roots.  It promotes a better conservation of the resources, because it reduces the evaporation more than a simple irrigation system.  It does not have runoff at the surface, and no water is disposed. 

RESULTS Using the PRET program, the Crop Coefficient Kc and the maximum evapotranspiration quantity Et were obtained to calculate the required amount of water.  Water gallons requires= (Et)x(#acres)x(1069.0663)  With Et=5.1 for June and July, 16,629.33 gallons of water per day will be required. 

TANK DESIGN FOR HARVESTING RAINWATER 

Since ancient times, rain water was stored for domestic uses. There is archeological evidence of water tanks built in 2000 BC for domestic and agricultural uses in countries like China and Israel.

Water cisterns ruins in Negev Desert, in Israel. (reference: http://rolandcastrojuarez.blogspot.com/2012_06_01_archive.html

ADVANTAGES (HARVESTING RAINWATER) The water is free of charge. It only needs the harvesting and maintenant.  Harvesting near the area it will be used, the transportation costs can be eliminated.  Water sources are always available, unlike the underground water that can be reached in certain areas.  It reduces the runoff that goes to the sewer. 

SOME CONCEPTS TO HARVEST RAINWATER 

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A surface to recollect the water (like the house’s roof).

Gutters to drive the water from the roof to the tank.

Filters, diverters and mesh that can remove the dust, leaves and debris from the water before reaching the cistern.

One or more water tanks are required.

System of transport for the water from the cistern to the field.

Reference: The Texas Manual on Rainwater Harvesting, 3rd Edition.

FIRST-FLUSH DIVERTERS 

These systems are in charge to remove the debris, dust, leaves, bugs and other contaminants that the rainwater may carry before reaching in the tank.

Reference: The Texas Manual on Rainwater Harvesting, 3rd Edition.

STORAGE TANKS 

Storage tanks or cisterns may be acquired from hardware stores. These tanks have a storage capacity up to 30,000 liters (6,600 gallons).

Higher capacity tanks are usually built in the place where it will be used.

VIEW OF A WATER CISTERN IN THE LAURA MERCADO SCHOOL FARM

Design made with Google SketchUp 7

Tank’s capacity: 6,600 gallons Tank’s diameter: 12’10” Height: 9’10”

RESPONSABILITIES OF THE OWNERS The water levels in the cisterns should always be monitored.  Also, the filters and gutters should receive the adequate maintenance.  Any crack or damage in any of the components of the system should be repair.  The school should adopt water efficiency policies for the use of the water in the field. 

COST ESTIMATES FOR THE WATER TANK Material

Cost

Capacity

Coments

Fiberglass

$0.50 – $2.00/gallon

500 – 20,000 gallons

It can last for decades without damages, easy to repair.

Concrete

$0.30 – $1.25/gallon

>10000 gallons

Thee is a risk of the concrete to cracks, but they are easy to repair.

Metal

$0.50 – $1.50/gallon

150 – 2500 gallons

Light weighted, easy to transport.

Polypropylene

$0.35 – $1.00/gallon

300 – 10,000 gallons

Light weighted and resistant.

Wood

$2.00/gallon

700 – 50,000 gallons

Preferably for esthetics.

Polyethylene

$0.74 – $1.67/gallon

300 – 5,000 gallons

Welded steel

$0.80 – $4.00/gallon

30,000 – 1 million Great capacity of of gallons storage.

COST ESTIMATES OF THE OTHER COMPONENTS Gutters (Aluminum, plastic, vinyl or galvalume) from $3-$12 per linear foot.  Roof cleaners-$400 up to $800  Water pumps- from $300 up to$600  Filters- $700 up to $2,600 For a system with a storage fiberglass tank of 6,600 gallons, the costs will be $13,200 (tank)+$100 (gutters) + $1800 (filters) +$450 (pumps) + $600 (roof cleaners) ≈ $16150 

CONCLUSIONS AND RECOMMENDATIONS The quantity of water required to satisfy the plant’s water demand may not be enough for the irrigation system to fulfill.  Other additional water sources are needed to supply the demand if the school want to use the entire farm year round.  We recommend that fewer quantity of plants be planted, and that they require less water in drought seasons. 

The school should seek professional orientation to convert it in a self-sustainable and ecoagricultural school, with specialized organizations in green building such as the USGBC.  The school should involve the students and the community in the process to grade the school as self-sustainable.  The teams should work so that the school can achieve and be certified as a LEED Green Building, because this cirtification could promote the school and the organization, at the same time that it will help improving the environment and save money. 

SPECIAL THANKS We would like to thank he Laura Mercado School, Mrs. Acevedo and Mr. Wilfredo Rivera for their cooperation in the community.  A special thank to Dr. Eric Harmsen, from the Agricultural Engineering Department of the Univeristy of Puerto Rico at Mayaguez, for all his collaboration and help in irrigation systems, and his web page www.pragwater.com 