What is EWB?

Engineers Without Borders (EWB) is an organization that connects students with communities around the world to implement engineering projects. Members practice hands-on engineering design, gain international experience and learn how to manage large-scale engineering projects all at once. With the help of technical and cultural mentors, students are fully involved in all aspects of the project. Being in EWB means being a committed member -- students communicate with the non-governmental organization and community, make decisions in project scope, brainstorm concepts, crunch numbers in design and, finally, travel on-site to build.

The Rose-Hulman Chapter

Currently, we are helping to expand a health clinic in Batey Cinco Casas, Dominican Republic. The clinic, Centro Medico, caters to 10,000 individuals in the Monte Plata region and wishes to expand its care and services. This portion of the project includes renovating a currently unused building, which will soon be used as an in-patient facility where patients can be monitored long term and given specialized treatment. Last summer, we constructed a roof along with Architecture for Humanity-Indianapolis, and this summer, we are installing a septic system to handle the increased load of the clinic.

Well, how did we get here?

EWB members work throughout the school year to design, plan and prepare for implementing projects in the summer. EWB Nationals has each chapter go through a project approval process before travelling. This process includes information-gathering trips to collect data and design parameters, formally written design documents and design presentations screened by professional engineers. In addition to working with EWB Nationals, we also fundraise for our trips and organize all the logistical details for travel and construction overseas.

The Basics

Who: Travel Team Summer 2011 (students: Abby Grommet, Ryan Oliver, Angelica Patino, Elaine Schaudt; mentor Dr. John Gardner, associate professor of Spanish)
What: Installation of septic system for health clinic
When: August 15-29, 2011
Where: Dominican Republic - El Toro (hotel in Monte Plata), Centro Medico (clinic in Batey Cinco Casas)
Why: Renovate old building into in-patient facility to expand services of Centro Medico

A Day in the Life

Dog barks and rooster crows echoing from the street below jolt us out of bed, as early as 4 a.m. After strapping on boots caked with mud from the previous work day, lathering on layers of 100+ SPF sun screen, spraying ourselves down with bug repellant and attempting to stretch our sore muscles, we usually frequent the local grocery store to grab five-liter jugs of water (which usually end up empty by the end of the day) and hit the fruit stand on the main street. The señor who runs the stand greets us with a smile and warm "hola," as he single handedly cuts the fruit with a machete and gives change to three to four customers at the same time. For only 35 Dominican pesos (less than one U.S. dollar), you can get a mix of freshly cut mangoes, pineapples, papaya, bananas, cantelope, watermelon and the choice of topping it all off with honey. We feast on this breakfast at the town plaza while people watching (and being watched). The scene looks something like this... men with worn faces and women in dusters eye the streets from their plastic lawn chairs on the sidewalk. Hoards of middle-school age kids shuffle along to school while sporting baby blue button ups, black backpacks and khaki pants. Another group of kids are up to something entirely different -- these shoe shiners chase around the men and women catching a ride to work and split their profits among themselves. An awkward commotion storms up as the local eccentric tries to weasel her way into getting free food from street vendors setting up shop. The occasional gentleman texting on horseback passes by.

After dropping off our room keys and chatting it up with Freddie at the front desk, we leave our hotel, El Toro, around 8 a.m. and take a 30-minute drive to Centro Medico. Rudy gives us a lift in a not-so-spacious truck, with one person comfortably situated in the front and four people practically sitting on top of each other in the back. With windows rolled down, we drive through the Dominican countryside as fresh air hits us and unkempt vegetation, overflowing rivers from hurricane season's recurrent rains, and almost invisible mountains meet our eyes. Sprinkled in here and there are small towns with brightly colored rows of wooden and concrete houses that melt into one another as we speed past. The town dance club looks unusually solitary without bachata and merengue beats pouring into the streets with crowds enjoying an evening El Presidente (the preferred drink) and couples stirring in the dim light. Mechanic shops roar with clangs and motor hums. Roadside restaurants grace the air with the scent of every type of empanada you can imagine and chicken prepared in more ways than you would like. Most buildings, filled with people bustling about their morning routines, draw people in with hand painted signs sprawled across them.

View from hotel El Toro	Looking down the street from our hotel

Locals zing past on motorcycles, sometimes with up to five people sandwiched together. Rudy points out a few landmarks -- the Monte Plata police station, prison, town brothel and cock fighting arena. The only reasons for slowing down are speed bumps (sleeping policemen), where kids try to sell us nuts and other various goods through the truck window, a still-drowsy dog that wanders into the street, huge pot holes that pop up every so often, chickens darting across the road or trees downed by the previous day's storms.

Transportation conditions	Bikers passing by

Stacks and stacks of green crate boxes, stamped with "El Presidente" in white print, signal that we're approaching the clinic. As we pass the entrance gate, lines of people spill out into the front courtyard, awaiting their turn to reach the front desk. We are greeted with curious stares and inviting smiles as we pull into the clinic property. We reach the road in front of the building that once was a housing complex for sugar cane harvesters but is now the clinic's in-patient facility in the making. It bore walls with faded turquoise paint, now boasting a new coat of yellow paint and a hurricane-proof roof sitting on top. We grab our backpacks and water jugs from the truck bed, excited and anxious for the full day's work ahead of us.

Renovated clinic building	Clinic with garden
Preparing for the day's work	Going over plans with the foreman

Covered in sweat, mud and, on bad days, slightly sunburned, we halt work around 5 p.m. Depending on what needs to be done, we may go on for another hour or two. Most of us surrender to sleep on the drive back, when Dominican pop blasting from Rudy's speakers seeps into our unconscious. Back at El Toro, we take turns showering and deliberate what neighborhood restaurant to check out. After wandering the streets, the urge to sleep overtakes us and we rest up for the next day.

Labor 1: reviewing pipe network plan	Labor 2: digging trenches

Labor 3: excavating septic tank pit

Septic System Design

Working with Dr. John Aidoo of the Department of Civil Engineering, as well as Mike Cline and Wil Painter from EWB-Indianapolis, we designed a septic system for Centro Medico. The system consists of two main parts: the piping network and the septic tank. The piping network essentially connects the septic tank to the in-patient facility building.

During the week break between winter and spring quarter last year, a team of students surveyed the property in order to calculate the appropriate slopes for the piping network, which is critical for the fluid in the pipe to be released into the septic tank. The placement of the septic tank also depended on data from the survey.

Elevation survey of clinic property	Layout of piping network (distances): blue lines represent where pipe must be laid, black numbers are the lengths of the pipes, and yellow boxes signify the placement of junction boxes

At each bend in the piping network, the pipes connect into junction boxes, or “los rejistros.” Junction boxes act as access points to eliminate clogs in the system that may disrupt fluid flow. In our design, the pipe slope is 0.125 inches/foot using 4’’ PVC pipe with junction boxes made of concrete blocks, mortar, cement filling, and #4 rebar.

Schematic of junction box

The septic tank requires a minimum capacity of about 1,200 gallons. The final dimensions of the tank are 11 foot long by 8 foot in height and 8 foot in width. This is based on the water usage and waste disposal of the in-patient facility, along with future plans of adding more bathrooms, a cafeteria, and, in the very distant future, a surgery center. The top and bottom slabs are made of pre-cast concrete, while the walls and interior baffle are made of concrete blocks, mortar, cement filling, and #4 rebar.

Overview of septic tank

Dimensioned drawing of top slab	Dimensioned drawing of bottom slab and baffle wall

Arriving on Site

Every single day, the Dominicans on our team get a two-hour head start by arriving on-site at 6 a.m. Stepping out of Rudy's truck, sounds of snappy Spanish shouts, laughs, shovels hitting soil and swishes of running water mix with crying babies and murmurs from patients waiting in line. After setting our bags aside on the back porch, the head honcho of the whole show swings by and loudly announces, "Angel Rojas está aquí." When handed a cup of coffee from a lady in the clinic kitchen, he returns an affectionate "Gracias, mi corazón."

Standing outside of our hotel

Angel Rojas (local civil engineer) and assistant	Daily necessities

Once the morning gets going, Angel has already smoked half a pack of Marlboros and, while lighting yet another, orders Chocoto direct trucks full of building supplies or to fetch tools from the tool room. Chicle (chewing gum), El Tigre (tiger), Henry, Frances and Daniel huddle around the manager Mejía and receive instructions on where and how deep to dig next. Once Mejía finishes, the guys resume their singing and pseudo mud fights between piling up mountains of dirt.

Mejía the horticulturalist (foreman)

Construction

Before any pipes were laid or slabs cast in place, both the pipeline trenches and septic tank pit were dug out -- so simple to say, not so simple to do. A critical part of the design was getting the elevations as exact as possible. Otherwise, gravity would work against us instead of for us, fluid would fail to drain into the tank, and the toilets and water fixtures in the building would be dysfunctional. (Note: Unlike in the U.S., most piping networks here rely on gravity flow alone rather than a pump.)

Here’s an overview of how we laid the pipes: Using surveying equipment, wooden posts were positioned to indicate the depth to dig and where the junction boxes would be located. String was pulled taut between each post to portray the necessary slope the pipe would need in order to function properly. Chalk marked the required width of the trenches, and once the ground was dug to the appropriate elevation, a bedding of sand was placed to help hold the pipe in position. Elevations were checked yet again with a rod with marked distance. Three important heights were marked with black electrical tape: the height of the ground to the string, the height of the sand bedding to the string, and the height of the pipe to the string. With all of these checks, and the simple measuring technique, we made sure that the pipe had the correct slope. We were always battling the rain, which would shift the sand and the dirt, causing changes in the slope, so we worked meticulously but efficiently. Once measurements were within a tolerance of ±3 millimeters, the pipe was further sealed in with sand and then finally backfilled with dirt.

Setting up surveying equipment	Bailing out trenches
Measuring slope of trenches	Backfilling trenches

While digging, unexpected challenges popped up -- buried concrete slabs to crack through, ceramic tubing from previous buildings to remove and inconveniently placed pipes from the current system to dodge when we place our pipes. These challenges turned out to be manageable and didn't alter the design of the pipe network. At this point, every single pipe is laid, and early tests show that drainage occurs properly.

Discussing how long the pipe should be to cover the length of the trench	Rotating shifts while backfilling final trench

Inside the final trench

Los rejistros are currently our next task, which called for a couple design sessions with Angel. Paging through the manual Angel authored in his college days, we calculated the minimum quantity of cement mix bags (210 kg/m2, or 3000 psi), sand, aggregate (gravel), and water for the mortar, filling, top slab, and bottom slab. He had us run a few calculations to find out the final count of rebar and concrete blocks we need. With this “take off,” or supply list, Angel had Choco scout out a combination of locally available materials and some shipped in from Santo Domingo. Alongside Victor, the master mason, and his assistant, we’ve laid the bottom slab and set the first layer of block. Rains and a hurricane threat have halted progress, leaving us around 3 days behind schedule.

Laying junction box caps

Building walls of junction boxes	Half-way completed junction boxes

With the inhuman strength of the Dominican work team, the septic tank pit has finally been completed after digging nonstop for eight days. However, we've stalled on laying the bottom slab due to the same weather delays. The actual digging of the septic tank pit has been quite the undertaking. The first layer of topsoil was soft to break through, but the clay layers seemed to increase in density the deeper we dug. Daily afternoon rains also slowed us down and forced us to shift around mud instead of dry ground. Groundwater seeped through the pit walls and combined with the rain. This meant that each day, we had to both bail and pump the water out of our "swimming pool" before digging could resume. Such a process took at least four to five hours.

Beginning of septic tank excavation	Already rain is filling the pit
Bailing the septic tank pit	Almost completely excavated septic tank pit
Septic tank pit completely full of water (3-4 hours of bailing)	Preparing trench for influent pipe to septic tank
Gluing two pipes together	Waiting for the septic pit to be pumped (we finally rented one)

This drainage brought another problem to the goats living on the other side of the wall—their hooves began rotting from the excess moisture. We’ve dug drainage lines to remove the standing water in their fields. While roaming the farm with Mejía, we tried our hand at catching baby goats and picking fruit (the 20 included coconuts, chinola, pineapples, etc) in the fields.

Septic tank being pumped out	Catching a goat

Visitors swing by as we work. Mayo, our buddy from last year, hangs around and borrows our cameras to record a mini dance performance or snap shots of the work crew. The loud talking from the porch is usually Henry’s niece, who shares her fruit with the group (only if you’re nice to her and she likes you. In one sour instance, Angel asked her name, and she retorted “Sin nombre!”). After reaching a stopping point for the day, everyone takes a quick nap before Rudy arrives to bring us back to El Toro.

Mayo

Henry's (worker) niece	Resting while waiting for our guauga to bring us to our hotel

What's for Lunch?

After sweating in the hot Dominican morning sun from hours of hard labor, we are eager for our much wanted lunch break. About midday, a lady from down the road arrives at the work site with a home-cooked lunch tightly packed in Styrofoam containers for RD$125 (a little over U.S. $3). We kick off our wet, muddy boots and rest our blistered and calloused hands while enjoying the authentic tastes of Caribbean cuisine.

As we carefully unwrap the bundle, making sure not to spill a morsel of the much coveted midday sustenance, the aroma of freshly cooked meat in a flavored sauce of herbs and exotic spices fills the air. A typical lunch also contains a colorful array of vegetables picked from one of the many lush fields that encompass the tropical island, as well as large mound of white rice smothered with a soup of spicy bean blend. This national dish is commonly referred to as the Dominican flag as the rice and beans depict the white and red colors of the flag, and the blue is... well... a figment of your imagination.

Traditional lunch

We carry over our plates to sit under the canopy of palm trees what surround the medical clinic. These trees provide our afternoon shade. The spectrum of colorful hues of flowering shrubs paints the epitome of this tropical paradise, creating the perfect ambiance for our afternoon rest. After scarfing down the 'comida' in a matter of minutes, our bellies are once again happy, and we shortly return to work only after allowing a crowd of hovering stray dogs to lick the remaining crumbs off our plates.

¿Porque, Irene, Porque?

Checking the weather before we arrived, the forecast predicted rain every day. Although disheartened, this was the only time of year we could all come down for the standard two-week implementation schedule. The first day, it was sunny in the morning and cloudy in the afternoons; it rained extremely consistently from day to day, usually from 3pm to 5 pm, with sprinkling throughout the day. Saturday, five days after starting to work, we came to the clinic, and the Dominican civil engineer, Angel Rojas, warned us of a tropical depression "muy enorme" coming our way. On Monday, what he predicted, except at a harsher level - a level one hurricane, was becoming reality.

When the grocery store opened, we rushed to stock up on jugs of water and crackers in case stores were closed for a few days and supply lines were disrupted. Strangely, no Dominicans seemed to "franicking" (frantically panicking). Apparently there was a previous scare two weeks ago -- Hurricane Emily -- and when it approached the island, everyone was released from work early to take shelter from the storm. Similarly, there were only strong winds and a torrential downpour, but nothing amounting to hurricane level.

Even so, there were many less people on the street, and the town had a darker, almost ghost-town-like feel. Usually, on the way to the friendly neighborhood fruit vendor, we pass by a corner where older men, perhaps policemen, sit around on their motorcycles, chatting it up. Just another street down, younger boys, mounted on bicycles, imitate the men. Many people are dressed up nicely, heading to work either on foot, by motorbike, or by Guagua (cheap public bus/van transport). Students trudge by with their parents, while other kids make scrubbing motions with their hands, trying to find people willing to have their shoes shined. People relax in the main square, a park with a central pavilion, eating breakfast from the many different vendors surrounding. All of this was missing on the day of the hurricane. The church, usually with daily mas and bells ringing, remained undisturbed. A few people were busily walking about, trying to beat out the storm while racing towards their home, and very few stores were open. The grocery was one of them, along with our daily fruit vendor cart. As the bright lightning stripes came closer, and the loud boom of thunder reverberated more deeply within our ears, we quickened our pace. Some of those around us seemed unworried, as they are used to these kinds of storms. No one was lining up at the store like what happens in Miami during similar circumstances. We seemed the most worried.

That day we left the clinic early and spent the afternoon in our hotel, waiting for any huge gust of wind to fulfill our excitement and fears. We watched the news, although in Spanish, without regress, tracking the path of the hurricane as it became larger and larger. Alas, after waiting for hours, our spirits were dashed and we all fell asleep early, like old women with nothing to do but knit and complete crossword puzzles, except without the materials to do even this. The rain had just come in spurts, and while it did soak some people riding home late, it was similar to the other rains we had seen earlier in the week.

Now our project is postponed due to thunderstorms, rain and standing water. In Puerto Rico, the communication network is down and hundreds of thousands of people are without electricity. In northern Dominican Republic, where the hurricane had more directly passed over than where we were, many bridges were destroyed, trees were downed, and flooding was occurring. We were lucky, in the sense of feeling only the outside edge of the storm with only low wind speeds and some heavy rains. While some of us had been interested in experiencing a hurricane for the first time, at least our work site would suffer minimal damage, causing us only a few setbacks. We still arrive at the worksite every day, hoping the rain will die down long enough for things to dry and for us to start laying more concrete. As we write this, we are under a small pavilion, overlooking our project, hoping for the weather to comply and for our excavations to remain relatively unharmed. As the hurricane moves so slowly over the ocean, at around 10 km/hour, the water that picks up is just dumped on us as the storm system grows. The upper layer of dirt is completely saturated, with the impermeable clay beneath stopping more water from seeping in. The water just flows out into the surrounding farms, drowning crops (even rice), and hurting animals. We can only hope that this ends soon so that we can continue with our goal of completing the septic tank before our final departure Monday afternoon.

Drainage

Sunny mornings almost always deceived us. Between noon and 2pm, the chorus of water droplets hitting the ground killed our hopes for dry afternoons. At the height of Hurricane Irene’s threat, two full days of heavy rains halted all progress. This was both good and bad—it gave us the down time to reanalyze our budget and discuss options for our next project, but it also filled all the junction box holes and septic tank pit to the brim with rainwater. With only a few days remaining, everyone felt quite unsettled about our prospects of finishing in time.

Double checking project's cost analysis

The rundown pump’s periodic need for repair slowed progress even more. Everyone dreaded these frequent breakdowns because that meant we had to bail water out by hand. Through both the pump and bailing, water levels eventually became low enough to resume laying the blocks for the junction boxes and inserting the bottom slab rebar for the septic tank.

The pump is working!	Before pumping
Stage 1 of pumping	Stage 2 of pumping
Stage 3 of pumping	It's dry!

Working to Completion

All junction boxes were constructed identically and only varied in depth. Each of the junction box walls were built up to ground level and had stucco applied to the inner walls for waterproofing. The interior flow lines between each pipe were contoured to direct fluid flow and reduce waste build up. Finally, grouting sealed the precast lids to the junction boxes.

Two projects by Rose-Hulman’s EWB team: (1) the roof on the in-patient facility completed last summer seen in the back, (2) this year’s the septic system installation on the clinic grounds, seen in the front	Junction box pit
Junction box without cap	Completed junction box

Most of the rainwater and groundwater was drained from the septic tank pit. However, the bottom of the pit maintained about 5 to 7 inches of water at the bottom, since that depth was too shallow for the pump. To solve this problem, a 2-foot long, 6 inch diameter PVC pipe was perforated and inserted into the center of the septic tank pit, where the elevation was the lowest. The head of the pump was inserted into the perforated PVC pipe, allowing for the water at the bottom of the pit to be removed.

We then put the bottom slab and interior baffle wall rebar into place, with approximately 8 inches between each piece of rebar. All 20 foot pieces of #4 rebar were shortened and angled by hand, which took up a half a day of work. We proceeded to mix cement with the hand mixer, also known as a ligadora. In addition to sand, cement mix, aggregate (gravel), and water, additives such as plasticizer and fiber were added to decrease curing time and increase strength. As we mixed the cement, the grumbling howl of the ligadora suddenly fell silent. Much like the pump, the ligadora broke down on us, causing us to resort to mixing by hand. Dominican engineer Angel Rojas saved the day yet again by returning the ligadora to working order, and the bottom slab was cast in place.

Rebar placement for bottom slab as designed	Overlooking concrete mixing process for bottom slab

Angel Rojas fixing the concrete mixer (ligadora)

The next morning, the first septic tank block was laid. The master mason first squared the corners, and then built up the septic tank walls. Every fourth layer, horizontal rebar was added. Eventually, the septic tank walls were built to the surface of the ground, and the top slab of the tank was cast in place.

Beginning to build the walls of the septic tank

Passing blocks down for wall construction	Completed walls of septic tank

Visitng Batey Cojobal and Batey Santa Rosa

Having completed the septic system at Centro Medico, we’re currently trying to determine our next project with the Batey Relief Alliance. An administrator with the BRA suggested that we may be able to implement engineering projects in neighboring bateys surrounding Batey Cinco Casas. Saturday was our last construction day, leaving Sunday as an opportunity to check out Batey Cojobal and Batey Santa Rosa.

In both bateys, septic system work would be viable, including latrine construction and building a community septic tank where current and new latrines would empty. Finding a central water source and delivery system for the communities is also a possibility, as well as conducting a housing project.

Private latrines (only the lucky few had them)	A typical home built from scrap materials of corrugated metal and palm wood
Local kids in Batey Cojobal greeting us	Elaine Schaudt hanging out with some kids in Batey Santa Rosa

Bringing in supplies to the clinic filled with waiting patients

If you have any questions about these projects or would like more information, feel free to contact the EWB-RHIT presidents, Alex Morelli, or Ryan Oliver.