Cleaning Up Carabuela:

What to do with Number Two

Team 7

Ian Compton

Adam DeYoung

Josh Scheenstra

Nathan Williams

Engineering 339/340 Senior Design Project

Calvin College

December 12, 2012


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©2012 Team 7, Calvin College

Executive Summary

Initial Project Summary

The focus of this project is to provide sanitary wastewater management practices for a small village in Ecuador. The village, Carabuela, is made up of about 500 homes and is located in the Andes Mountains. Carabuela currently has a defective treatment system that is releasing untreated or poorly treated waste into a nearby river. The waste collection system is in an unknown condition and will be evaluated and redesigned as needed.

Partnering Organization

The project was proposed through Calvin College by the global healthcare/ministries organization called HCJB (Heralding Christ Jesus’ Blessing). HCJB operates largely out of Ecuador and does substantial work with community development projects. They have partnered with Calvin College for a while and are working with the team to help bring more sanitary conditions to the village of Carabuela.

Collection system

The village has an existing collection system that services approximately half of the homes. The condition and location of the system is currently unknown and will need to be evaluated. Depending on the state of the collection system, a completely new system will be designed or only broken-down portions.

Treatment Facility

The treatment facility is the largest part of the design. The two main requirements of the facility are that it must be a passive process and it must have low costs. The current preliminary design is a set of bar screens, followed by a set of anaerobic ponds in parallel, and an infiltration bed to discharge the treated effluent to the groundwater. This process will operate passively and require minimal maintenance and installment costs.

Irrigation Distribution

A feasibility study to use the treated effluent for irrigation will be done after gathering more pertinent information regarding Carabuela.

Travel Requirements

Team Carabuela will be traveling to Ecuador in January for 10 days to gather information about Carabuela. This trip will entail evaluating conditions of the current collection system, surveying topography, testing soil types, locating available land, working directly with HCJB, and communicating with the local people to establish a relationship and understand the cultural parameters affecting any possible designs.

Costs

The costs for the trip include airfare, room and board, food, equipment rental, and ground transportation. The estimated cost per person for this trip then is $1700; $1000 for airfare and a $700 contingency fund for daily expenses. This is based on a cost estimate of about $55/day given by HCJB.

Next Steps

The next steps of the project are to refine the initial treatment design and begin validating assumptions made in the collection system model. This will mainly come through the information gathered from the trip to Carabuela.

Table of Contents

Executive Summary ii

Table of Contents iv

Table of Figures vi

Table of Tables vii

1. Introduction 1

1.1 The Team: Cleaning Up Carabuela 1

1.2 Project Background 1

2. Problem Statement 2

3. Partnering Organization 2

3.1 HCJB 2

3.2 The Village and Context 2

4. Existing Conditions 5

4.1 The Treatment Plant 5

4.2 The Collection System 6

4.3 Village Demographics 6

5. Design Constraints 7

5.1 Flows and Loads 7

5.2 Effluent Standards 8

5.3 Location 8

5.4 Costs 8

6. Design Norms 9

6.1 Cultural Appropriateness 9

6.2 Caring 9

6.3 Stewardship 9

6.4 Transparency 9

7. Design 10

7.1 Collection System 10

7.1.1 Preliminary Design 1.1 10

7.1.2 Preliminary Design 1.2 12

7.1.3 Materials Standards 19

7.2 Treatment 19

7.2.1 Treatment Options 19

7.2.2 Treatment Decision Matrix 25

7.2.3 Selected Treatment Design Alternatives 26

7.3 Effluent 29

7.3.1 Effluent Targets 29

7.3.2 Irrigation Feasibility 30

8. Construction and Maintenance 30

9. Costs 31

9.1 Team Costs 31

9.2 Project Costs 31

9.2.1 Treatment System Cost 31

9.2.2 Collection System Costs 32

9.2.3 Design Costs 33

9.2.4 Cost Summary 33

10. Work Plan 33

10.1 Interim 33

10.2 Trip 34

11. Works Cited 35

Table of Figures

Figure 1 : Map of Ecuador with a star on Carabuela 3

Figure 2 : Overview Map of Carabuela 4

Figure 3: Average Yearly Temperatures in Quito, Ecuador 5

Figure 4: Average Yearly Rainfall in Quito, Ecuador 5

Figure 5: Current Treatment Facility 6

Figure 6: Preliminary Sewer Design 1.1 AutoCAD Approximate Pipe Layout for Entire System 11

Figure 7 : Preliminary Sewer Design 1.2 SWMM Map with Manhole Invert Elevations and Pipe Slope 13

Figure 8 : Preliminary Sewer Design 1.2 SWMM Maximum Velocities 15

Figure 9 : Preliminary Sewer Design 1.2 SWMM Surface and Pipe Profile View of the Longest Reach (Southern Most Point to Discharge) 16

Figure 10 : Preliminary Sewer Design 1.2 SWMM Model Conduit Peak Flows 17

Figure 11 : Preliminary Sewer Design 1.2 SWMM Model Conduit Capacity (Ratio of Depth to Full Depth) 18

Figure 12: Manually Cleaned Bar Screen Structure Plan and Profile Views 20

Figure 13: Typical Septic Tank Design 22

Figure 14: Typical Bio-Filtration Setup 23

Figure 15: Constructed Wetlands 24

Figure 16: Infiltration Bed 25

Figure 17 : Waste Stabilization Pond Layout 27

Table of Tables

Table 1 : Major Constituents of Typical Domestic Wastewater 7

Table 2 : Current and Projected Sanitary Flows 8

Table 3 : Preliminary Design 1.1 Pipe Lengths and Diameters 10

Table 4 : Collection System Flow Calculations 12

Table 5 : Sewer Size and Minimum Slope to Maintain a 2ft/s Flow Velocity 14

Table 6 : Piping Materials 19

Table 7: Horizontal Flow Grit Chamber Design Criteria 20

Table 8 : Decision Matrix 26

Table 9 : Waste Stabilization Pond Design Parameters 27

Table 10 : Pond Sizing 28

Table 11: Recommended Rates of Wastewater Application for Trench and Bed Bottom Areasa 28

Table 12 : Fresh Water Discharge Effluent Standards in Ecuador 29

Table 13 : Michigan Department of Environmental quality Standards for discharge into Ground Water 30

Table 14 : Breakdown of Trip Costs 31

Table 15 : Initial Estimated Wastewater Treatment Facility Costs 32

Table 16 : Initial Estimated Wastewater Collection System Costs 32

Table 17 : Initial estimated Design Costs 33

Table 18 : Total Cost Estimate 33

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1. Introduction

1.1 The Team: Cleaning Up Carabuela

Team Carabuela is composed of civil/environmental engineering students; each member brings a variety of experiences, interests, skills, and backgrounds to the design project.

Nathan Williams

Nathan was born and raised in Howell, Michigan. He is a senior at Calvin College expecting to graduate in May 2013 with a Bachelor of Science in Engineering degree. He is interested particularly in the environmental field but would like to work with water quality or quantity. He interned in the summer of 2012 at the City of Kentwood, working with the municipal engineering department.

Adam DeYoung

Adam was born and raised in Hudsonville, Michigan. He has a desire to use his skills acquired in Calvin College’s Engineering program to provide clean water and quality water wherever God will tell him to go. He has previously been involved with Varsity Athletics in Basketball and Track and Field at Calvin College. He has been involved in youth ministry for three years through a summer camp in Montana and Young Life in a local high school. This past summer, 2012, Adam worked as an intern at Vriesman & Korhorn Civil Engineers completing a Global Positioning System (GPS) survey, a witnessing project, and supervised new utility construction. His gained experience using the GPS will be put to use when the team travels to Ecuador. He desires to serve others with his engineering, by providing for their needs, and sharing the Gospel.

Ian Compton

Ian is a senior civil engineering student from Duanesburg, New York. He had the great opportunity to work with HCJB Global, the partnering mission organization of this project, in the summer of 2012. He worked specifically with the community development team in Quito on various clean water projects throughout Ecuador. He is privileged to have the opportunity to work with HCJB again. He is mostly interested in the hydraulic and environmental aspects of the project.

Joshua Scheenstra

Joshua Scheenstra is a senior at Calvin College who was born and raised in Kenya. His family has served as missionaries to an unreached people group for the past 26 years. He has participated in numerous community development projects in developing countries and many of them had to do with providing clean water. He has interned for Tulare Irrigation District the past three summers in California’s central valley. He is mostly interested in the hydraulics and structural aspects of civil engineering.

1.2 Project Background

The village of Carabuela Ecuador is a small, underprivileged community of approximately 500 homes tucked in the Andes Mountains approximately 100 kilometers north of the capital city, Quito. The mission organization HCJB Global (Heralding Christ Jesus Blessings) is an international organization focused on community development in developing countries and has established large presence in Ecuador, and specifically in Carabuela. Recently, HCJB implemented a water distribution system in the village but also realized the village’s desperate need for a wastewater collection system and treatment facility. Currently, there only exists a partial collection system and all of the effluent is discharged into the local stream untreated. To solve this problem, Team Carabuela, is partnering with HCJB to design the wastewater collection system and treatment facilities for them to implement in the near future.

2. Problem Statement

The goal of this project is to design a new wastewater collection and treatment system for Carabuela, Ecuador. In addition to improving sanitation, the main constraints of the project are cost, ease of design and a passive treatment facility that requires no power consumption. Keeping costs low is of high importance for the village and the organization. The design must also be able to operate passively in order to keep maintenance and labor requirements low.

3. Partnering Organization

3.1 HCJB

Team Carabuela is partnering with the international mission organization HCJB Global. HCJB works with healthcare provision, community development, and multimedia ministry. They operate on almost every continent with a strong base in Ecuador and the entire Latin America. HCJB has been very active in Ecuador with both their radio and healthcare ministries. Especially from an engineering standpoint, HCJB has worked on many projects, from clean drinking water to treating wastewater. Students from Calvin College have often partnered with HCJB in the past to provide clean water needs to various villages or organizations in Ecuador and around the world.

3.2 The Village and Context

The village we are working with is called Carabuela. Carabuela is a village of about 500 homes a few hours driving distance north of the capital city, Quito. Ecuador is located in South America and straddles the equator. Ecuador is divided into three main geographic regions: La Costa (the Coast), La Sierra (the Highlands), and La Amazonia (the East). La Costa is made up of the coastal western side of Ecuador, La Sierra is comprised of the Andes Mountain range through central Ecuador and La Amazonia is made up mostly of rain forest.

Figure 1 : Map of Ecuador with a star on Carabuela[1]

Carabuela is located in La Sierra in the Andes Mountains and has a relatively mild and dry climate because of its altitude. A simplified overview of Carabuela can be seen in Figure 1. In this figure, the contour of the village is shown along with roads, and the stream running through the village. Because Carabuela is in the same climate zone as Quito, they have similar temperature and precipitation ranges. To see average yearly temperature and rainfall, see Figure 3 and Figure 4, respectively.

Figure 2 : Overview Map of Carabuela[2]

Ecuador gained its independence from Spain in 1820 and has been plagued with political instability throughout most of the 19th and 20th centuries. It is currently a republic and has been holding democratic elections since the late 1970s. Economically, Ecuador is growing and has stabilized considerably over the past few decades. Almost half of its exports are crude oil related and the rest is made up mostly of agricultural products, such as bananas and coca[3]. Ecuador has also improved in the health care and infrastructure development areas over the past few decades; however, rural areas, such as the area surrounding Carabuela, are still in need of much improvement.

Figure 3: Average Yearly Temperatures in Quito, Ecuador[4]

Figure 4: Average Yearly Rainfall in Quito, Ecuador[5]

4. Existing Conditions

4.1 The Treatment Plant

The initial treatment plant for the approximately 200 homes that were connected to the collection system was a septic tank and leach field (Figure 5). The leach field was undersized and became saturated[6]. Untreated wastewater is now discharged into the river by the school (Figure 5). This treatment system failed and an adequately sized treatment system is needed.

The septic tank could be used with a rebuilt treatment field to treat a portion of the wastewater but most of the wastewater needs to be diverted elsewhere. The location of the current drainage field is concerning because of its close proximity to the river and presumably the groundwater table as seen in Figure 5. The size and status of the septic tank and drain field can be verified upon visiting the site.

Figure 5: Current Treatment Facility[7]