In August 2008, seven members of EWB-UWP returned to Ghana to implement some of the projects outlined by the 2007 Assessment Trip. The two projects implemented involved the Papase Roman Catholic Basic School, and a drainage culvert through the village of Nsumia. The Papase School project involved the installation and landscaping of a gravel drive as well as several drainage and erosion control measures and the donation of textbooks and teaching guides to the library. The Nsumia drainage project involved the stabilization of an existing drainage channel and modification of the existing inadequate culvert system. The goal of the implementation trip was to build a sense of trust with the respective communities while improving the quality of life with respect to health, education, and mobility for these communities. The projects implemented were also based in part on the ability of the community to replicate them in the future without EWB intervention, integral to the overall success of the project. Additionally, the close working relationship with the communities inspired and challenged them to develop a sense of ownership to these projects, maintain them, and also be able to duplicate some of the basic solutions to similar problems in the region. The trip also served as a valuable learning tool for future project selection and implementation strategies. All projects were selected to act as trust-building, gateway projects. It is critical that EWB-UWP build a strong relationship with the communities interacted with to facilitate return trips and initiate community support so that additional improvement of the existing conditions may be realized.
The main focus of the Papase School site was to address the erosion issues faced by the school, including areas around the foundation of the buildings, channeling erosion of areas in the courtyard, the outflow of the drainage channel, and protection of the proposed new driveway. The facilities, as previously mentioned, are in excellent condition. However, the above erosion issues, if left unaddressed, would be cause for major concern in the future. Actions were also taken to create a driveway, which would provide easy access to the Papase School and allow the school to be better recognized from the road.
A driveway was constructed at the Papase School in order to improve accessibility to the school and increase its visibility. The driveway was constructed with six inches of mixed rock base course and a 5/8” aggregate surface to a depth of four inches. Boulders roughly 9 inches to 18 inches in diameter were placed in the ditches of the driveway to slow the velocity of the water flowing through the ditches along side the new drive. Around the driveway, various plants were planted to further help with erosion and also to add to the aesthetics of the school. A sign declaring the site as the Papase RC Basic School was placed at the end of the driveway. This was done at the request of the village in order to further iterate the location of the Papase School to passersby. The final phase in the erosion prevention of the driveway project was planting grass around the driveway.
The only previous effort to deter erosion in the school premises was a drainage channel around one of the school buildings. The channel was built to collect water from the building’s roof and runoff from the surrounding area, allowing the runoff to safely flow around the building without compromising the stability of the building’s foundation. However, these channels were not well kept and were filled with sand and other debris. Also, the outlet of the channel was blocked by sand impeding the flow of the water and causing water flowing out of the channel to erode the footpath used to access the other school buildings.
A decision was made to create an extension of the channel 35-feet past the foot trail to an area of dense vegetation. Plans for the channel, constructed out of four-inch concrete reinforced with rebar, were to continue the existing channel’s five percent grade. Upon digging a ditch for the channel’s extension, a slab of concrete was discovered approximately one foot below the ground surface. Upon asking the Papase community, it was discovered the slab was created the previous spring in order to help with preventing the erosion of the walkway. The slab was previously used to carry water from the channel to vegetation behind the school, however the slab did not have any sides. The lack of sides caused two problems. First, the slab would not be able to direct any water without sides. Second, the slab was not able to prevent sand and debris from covering it.
The existing concrete slab was left in place and a new channel was formed on top. Riprap was placed at the outflow of the channel to slow and spread runoff. To prevent eroded material from entering the channel and potentially impeding the flow of water in the new channel, a berm was created on the uphill side. The berm consisted of rocks, discarded sandcrete blocks, and clay. The clay was then packed down using the ends of logs as tamps and by people walking over the berm. Villagers and school officials were provided instructions to keep the berm from silting in so that runoff remains properly channeled.
The final project at Papase was to slow the flow of water and preserve the foundation of one of the school buildings. Due to the shedding of water from the roof, extensive erosion of the building’s foundation had already exposed the footing and undermined the foundation. To sustain the foundation’s integrity, large stones ranging from six inches to two feet in diameter were placed next to the foundation to help prevent further erosion. The indicated size of stone was all that was available from the local quarry.
The large volume of water coming off the roof of one of the school building caused gullies to form running down the hill toward a school building and the driveway. To of water, allowing the water to infiltrate into the sandy soil. First, a grader was used to roughly shape the earth into three flat terraces. Second, two pieces of bamboo approximately four inches in diameter and eight feet long were stacked on top of each other to retain the fill which was placed behind them. To keep the soil beneath the bamboo from eroding away, stone was placed along the front of each terrace. The ends of each terrace were stabilized by larger boulders. Finally, community members planted grass in order to have vegetation further retain the soil.
A shortage of books by the Papase School was noted in the course of the Chapter’s August 2007 visit. As a result, over 400 pounds of textbooks, workbooks, notebooks, and teachers’ manuals were donated to the school of Papase by the EWB Team. The subjects of these books included science, math, geography, English vocabulary, grammar, and history. These texts more than doubled the existing supply of books owned by the school
The culvert to be repaired consists of a 36-in cast-in-place concrete circular culvert with approximately thirty-six inch wing walls. From visual rain event observations on September 1, 2007, the culvert appears to be installed properly with the size, length, and slope providing adequate capacity prior to neglect and post installation modifications. Since installation, the culvert appears to have received no maintenance and consequently has severely eroded inlet approach and exit apron. The haphazard addition of a misaligned 18-foot section of a 24-inch reinforced concrete pipe has severely restricted the capacity of the drainage components. The 24- inch culvert section is assumed to have been added for the protection of nearby business and residential structures. Unfortunately, the additional culvert only alleviated or diverted the erosion problem long enough for additional structures to be built near the outfall of the high flow culvert. The adjacent market and a newly constructed public gathering building were in eminent danger of collapse if erosion is allowed to continue at the present rate.
The first step in the project was the removal of the existing 24-inch inch culvert to make room for the new trapezoidal channel. The culvert section was approximately fifteen feet long and buried halfway in clay and large rock with an estimated weight of 15,000 lbs. The removal of the material obstructing the culvert was conducted on Monday, August 18th. For safety considerations, removal of the existing 24” culvert was deemed necessary by heavy construction equipment. Figure 15 depicts the trapezoidal channel design.
Through the local Assemblyman, arrangements were made to remove the lower 24-inch culvert with heavy equipment from Mansco Quarry on Monday, August 18th. The area was then shaped to accommodate the forms for the new trapezoidal channel. Due to the enthusiastic work attitude of the residents of Nsumia, more native material was removed than necessary, however, the EWB viewed the event as a demonstration of the commitment by the villagers to work with the EWB Team. Sediment and debris were also removed from within the 36-inch culvert and the existing channel downstream to provide adequate flow. The 36-inch culvert’s cross-sectional area was reduced by approximately 75-percent due to sedimentation prior to cleaning.
The base of the concrete channel was poured on Wednesday, August 20th. All concrete was mixed by hand in an open area adjacent to the project site. It was placed with a thickness of six inches and reinforced with rebar to ensure adequate strength if the channel were to reach full flow capacity. The most difficult part of pouring was convincing the aiding community members that a 1-2-3 mix was needed, (a mixture that is one part cement, two parts sand, three parts aggregate). The traditional mix utilized by the local population is composed of seventy-five percent sand and twenty-five percent concrete, which explains the short design life for many locally engineered structures. The traditional mixture is cheaper, but also weaker than the proper way of mixing concrete and often lasts only 1-2 years. The base of the concrete channel, over two cubic yards, was entirely poured on day five by four team members and a dozen community volunteers.
The day after pouring concrete Friday, August 22nd the outflow of the trapezoidal channel was lined with rip rap. The rip-rap used to line the channel extended 115 feet and was composed of six-inch to 24-inch diameter stone. This was significantly longer and consisted of larger rip rap than estimated. With the help of the villagers 30 cubic yards of stone was placed in a single day.
The additional rip rap rock was placed around the 36-inch culvert inlet to act as a filter for sand preventing clogging of the culvert. The rock would also protect against the erosion of the culvert’s inlet by dissipating energy to ensure the roadway does not continue to deteriorate over time. The Community Youth Leader, Nicholas, was appointed site manager and agreed to maintain the channel by keeping it free of debris such as sand and garbage.
On Saturday (day eight), two days after the pouring the sides of the channel, the Nsumia village removed the forms for the top of the channel prior to the EWB group’s arrival. The third day after pouring the concrete, day nine, the bottom of the forms were removed voluntarily by the community prior to the team’s arrival at the site The village was in the process of backfilling the void behind the channel’s wings using the soil left from excavating the area for the new channel. Also, several masons from the community were smoothing out the face of the channel with mortar. Rip-rap was used to cover the edges by the channel.
While in Ghana, the EWB Team also met with representatives of EWB –Ghana and local officials, donated medical supplies to a local clinic, tested water quality on local wells, and gathered more information regarding the overall project area.
In the course of the team's stay in Ghana water from five wells in three separate villages was sampled. Well #1 was located in Doboro, was had dug and approximately 23-feet to the water surface. Well #2 was located between Papase and the Papase School and was a pump operated, drilled and cased well. Well # 3 was located on the outskirts of Papase and was a pump operated, drilled and cased well. Pumps #4 and #5 were located on the outskirts of Nsumia. In addition, a water sample was collected from a large puddle composed primarily of runoff from the community dump in Doboro, located approximately 300-feet from well #1. Results from the samples are pending analysis.
The EWB Team received a donation of three large boxes of medical supplies prior to departure for Ghana. The supplies donated included a large assortment of bandages, gauze, dressings, and antibiotic ointments. Stethoscopes, blood pressure cuffs and medical scissors were also included in the assortment of medical supplies. On the last day the EWB Team was in Ghana, the supplies were donated to the Pokrom-Nsaba Health Centre, a local, government-run clinic located in the District just east of Nsawam. The head physician indicated the clinic covers a massive area including the villages the Chapter is partnered with.
Prior to the August 2008 trip the Chapter established connections with a representative of EWB-Ghana, Mr. Sam Gamson. The team met with Mr. Gamson and he also toured both the Papase and Nsumia project sites. An arrangement was made so that EWB-Ghana would ensure maintenance would be done on both sites and also update EWB-UWP with site conditions in the course of the year. A longer term working relationship with EWB Ghana will be cultivated, perhaps to partner in future projects.
The EWB Team also met with the district engineer, Mr. K. Sarfo-Brobbey to discuss future and current work in the area. Our main goal of the meeting, besides establishing a new contact, were to acquire the latest KVIP toilet plans which are commonly used in the greater area, and the district's development plan so that the EWB Team can collaborate with ongoing governmental efforts. An end result to the meeting was that a local newspaperman accompanied the EWB Team to each project site and witnessed the donation of the medical supplies to the health clinic. The Chapter expects to receive copies of any subsequent publicity through EWB Ghana.