To Recap, HHI contacted the company ARUP to develop the design of the IMPV school in Timo, Haiti.

This project aims to bring a much-needed new school facility in the remote, mountainous community of Timo. The school will be attended by around 225 students between the ages of 3 and 15. The scope of work includes design of the school buildings, design of the latrine block, and overall site grading design.

To date, preliminary earthworks have taken place, which included the construction of retaining walls around the perimeter of the site as well as levelling the ground surface. The next stage of works is the construction of the latrine block. Due to availability of funding, the design and construction of the latrine block will precede that of the school itself.

Photo of the Retaining Walls Completed

After undertaking a review of various toilet systems and assessing the site conditions of the IMPV School site, the ARUP team has concluded that double ventilated improved latrines (VIP) would be the most optimal proposal for this site. VIP latrines are a tried-and-tested method of providing sanitation in isolated areas. They have a proven track record of successful installation around the world.

Double VIP latrines are comprised of two identical sealed pits, supported by stable foundations and covered with concrete slabs, and ventilation pipes that extend above the roof of the latrines to draw away unpleasant odors. They will be designed to handle seismic risk.

The bottom of the latrine pits will be partially exposed to the soil underneath to allow for the flow of leachate from the contents of the pit to the soils. The site around the latrine block will also be graded in such a way as to divert as much rainwater as possible away from the latrines to limit the amount of water seeping into the pits.

In addition, toilet seats will also be provided so that children will not have to squat over the pit holes, sufficient lighting will be provided within the latrine blocks to promote a sense of security, clearly-defined paths from the school buildings to the latrines will also be provided for this reason, and handwashing units with soap dispensers will be placed.

Supplying robust handwashing units in conjunction with the latrines is imperative in the promotion of good hygiene and prevention of the spread of disease within the school and, by extent, within the community of Timo. This is why supplying clean and renewable water to the site will be part of the next phase in this project.

Illustration of Double VIP Latrine 

The two main sources of water at IMPV School will be rainwater and spring water. Spring water will be the primary supply of water for the handwashing units. This water is delivered to IMPV School by pipe from the nearest freshwater source known as Kamatin Spring.

In addition to spring water, rainwater will be collected on site and serve as a back-up supply for the handwashing units, in case spring water supply is ever interrupted. Rainwater can also be a source of water for cleaning and for irrigation. Collected rainwater will be stored in rainwater tanks. All three buildings (school buildings and latrine block) will have pitched roofs and gutters to collect rainwater and deliver it to the tanks.

A total of three rainwater tanks are proposed on site; one at each building. The tank that will serve as back-up for the handwashing units will be located at the south end of the latrine block. The size of the tank will be dictated by the height of the latrine block roof.

The tank will have an overflow system to direct any excess rainwater away from building foundations. In addition, a first-flush diverter will be provided to remove any excess debris or sediment that accumulates in the rainwater collected from the roofs. First-flush refers to the initial storm runoff generated atop a roof; it is typically dirtier than average because this runoff essentially washes the roof of all sediments that have accumulated on it since the last rainfall event. (See illustrations below)

Illustrations of Rainwater Collection System

For this project, a total of 10 latrines will be provided: 4 for girls, 4 for boys, and 2 for staff. Assuming a 50-50 split between girls and boys, this quantity of latrines is equivalent to 1 latrine per 28 girls (113 girls to 4 latrines), 1 latrine per 28 boys (113 boys to 4 latrines), and 1 latrine per 7 staff members (14 staff members to 2 latrines).

Prior to construction, groundwater levels in the surrounding area will also be verified in order to mitigate the risk of contaminating groundwater supply. It is typically recommended to ensure at least a minimum horizontal distance of 30 meters between a pit and water source and a vertical distance of 2 meters between the pit and the groundwater table.

Overall, the promotion of good hygiene will be the key to the success of these sanitation facilities, and there is no better place to spread awareness of this than in a school. By doing so, students will not only learn how to maintain proper hygiene within the school, but they will also likely bring the habits they form at school to their homes, thereby helping to promote proper hygienic practices within the community of Timo and beyond.

If you are interested to see more detailed blueprint drawings and layout designs of the planned latrines, click here.
If you are interested to learn more details about this project, click here.