Appropriate engineering solutions for developing nations

Post on 07-May-2015

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A presentation providing a brief summary of volunteer engineering projects I have been involved with in Honduras while working in collaboration with the Civil Engineering Department at CSU, Chico and Universidad Politécnica de Ingeniería.

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Appropriate Engineering Solutionsfor Developing Nations

California State University, Chico in collaboration with

Universidad Politécnica de Ingeniería

Access to Sanitation• WHO – Estimates 2.6 Billion people are without access to improved

sanitation facilities worldwide (most in developing countries)– Clean drinking water

» 900 million people without access to clean drinking water– Wastewater treatment– Solid waste management

• Problems associated with lack of sanitation– Increased risk of pathogen transmission

» WHO – Estimates 1.5 Million children under age of 5 die every year from diarrhea

– Disease– Virus– Parasites

HONDURAS• Population – 7,989,415• Population below poverty line - 59%• Unemployed or underemployed - 36%• Major infectious diseases;

– Food or waterborne diseases• Bacterial diseases• Hepatitus A• Typhoid Fever• Helminth – Ascaris infections

– Vectorborne diseases• Dengue Fever• Malaria

– Water contact diseases• Leptospirosis

Projects in Honduras

• Sustainable Wastewater Treatment and Reuse– Renovation and Expansion of existing Natural Wastewater

Stabilization Lagoons. Tela, Honduras• Solid Waste Management

– Proposed closure plan of open dump and new management plan for new sanitary landfill. Tela, Honduras

• Sanitation and Medical Facilities – Design, procurement, and construction oversight for

recyclers residing in an open dump. Tegucigalpa, Honduras

Currently owns and operates a natural wastewaterstabilization lagoon system serving 8,000 residents.

Municipality of Tela, Honduras

Lagoon System

Caribbean Ocean

Tela, Honduras

Rio Hylan

Primary Lagoon

Tertiary Lagoon

Secondary Lagoon

Rio

Hyl

an

Problem Identification – Sludge Accumulation

• 15 years of sludge accumulation

• Sludge had reached a depth of 4 meters

• Approximated volume of sludge is 3,000 cubic meters

Problem Identification – Flow Measurement

• Improper design and construction of two Parshall flumes.

• No flow measurement of influent or effluent wastewater.

• Lacking grit chamber.

Problem Identification – Treated effluent and sustainability

• Treated effluent is discharged into the Rio Hylan

• Treated effluent could be used for agriculture

• Tertiary lagoon could also serve as a Tilapia farm

Problem Identification – Site Safety

Solutions and Implementation Process

• Initial steps;– Collaborate with the Municipality– Site investigation

• Work on feasible plan of action– Develop design report to submit to Municipality

• Assist Municipality with funding and technical guidance through implementation

Sludge Removal

Parshall Flume

Implementation

• Sludge Removal – Bypass channel– Drain lagoon– Remove sludge – Store on-site

• Improve system sustainability– Parshall flume– Proposed reuse projects

Implementation – Bypass Channel

Bypass construction    

Bypass channel dimensions Value UnitsLength 130mWidth 0.6mDepth 0.7m

Bypass channel costs   Materials 59,000LpsLabor 112,500Lps

Total cost of bypass channel171,500Lps

8,575USD

Implementation – Draining Primary Lagoon

• Pump and siphon draining

• Time to drain – 88 hours

Implementation – Desludging Primary Lagoon

Desludging Process    

Sludge removed 2,860m3

2007 SubTotal 160,636Lps2008 SubTotal 85,503Lps

Total cost of desludging246,139Lps

13,539USD

Implementation – Parshall Flume Installation

Arrival of TRACOM’s donated Parshall flume on-site

Installation of fiberglass flume

Properly operating flow measurement device

Parameter Units Tela Effluent

Calcium mg/l CaCO3 21

Sodium mg/L 21,04

Magnesium mg/l CaCO3 8

Alkalinity mg/l CaCO3 102

Total DissolvedSolids mg/L 177

Conductivity uS/cm 268

Parameter Removal Units Tela Influent Tela Effluent Restricted Agriculture1 Aquaculture1

Fecal Coliform

4.0 log 10 CFU/100ml 3x106-6.5x106 3x102-6.5x102 <105 <104

Helminth Eggs

100% MPN/L 4—16 0 <1 0

1. World Health Organization 2004

Sustainable Reuse Potential - Effluent Quality and WHO Guidelines

Possible Land Application

Caribbean Ocean

Tela, Honduras

Proposed Nursery Location

Possible Aquaculture

Agriculture reuse installation cost21,138 Lps

1,119 USDAquaculture reuse potential revenue

117,800 Lps6,200 USD

Solid Waste Management

Solid Waste Disposal Site

Wastewater Stabilization Lagoons

Solid Waste Management in Tela

•Birds

•Mosquitoes

•Rats

•Live stock

Vectors

Scavengers

•Live and work in the dump

•Only source of income

•Numerous children

Leachate & Methane

Medical Waste

Special and Hazardous Waste

TiresIf buried, tires will eventually

rise to the surface of the landfillTires hold water or leachate

that is hazardous and is a breeding ground for insect vectors such as mosquitoes

ChemicalsMay leak and harm workers,

scavengers, and animalsMay react with other chemicals

deposited in the dump, possibly forming a more toxic byproduct.

Currently no separation of Tela’s solid and special wastes

Tela Dump Closure

• Provide durable surface drainage systems over the landfill– Control infiltration of rainfall into the waste– Control erosion of its surface (by wind and water runoff)

• Control the migration of gas and leachate generated within the landfilled waste

• Control disease transmitting vectors

A proper design for closure of a dump ensures that the waste will be covered with a minimum thickness of soil, known as the final cover (or cap). A properly designed final cover should:

Tela Dump Closure

Sanitary Landfills in the U.S.

Fully mechanizedMinimal land usage and cover material

requiredNot feasible for developing countries

due to:Cost considerationsEquipment maintenance

requirementsCover material requirementsLack of skilled labor

Solid and hazardous waste in the U.S. is regulated under the Environmental Protection Agency’s (EPA’s) Resource Conservation and Recovery Act (RCRA) of 1976.

Alternative Methods: Canyon/Area Method Landfill

Compacted daily cells of waste are built into designed ‘lifts,’ that are abutted against a canyon wall.

Alternative Methods: Trench Method Landfill

Waste is deposited in the trenches, and when the trench is full (which will occur approximately once-per-month for a properly designed trench), the excavated material is used as cover.

A series of properly sized trenches in parallel are excavated as required, depending on the process design.

Trench Method LandfillImmediate availability of cover without the need for full-

time heavy equipment to compact, excavate and haul cover is a major advantage of the trench method.

Trench Method

Leachate, Methane and Decomposition

COMMUNAL SANITATION FACILITIES AT THE TEGUCIGALPA SOLID WASTE

DISPOSAL SITE

Municipality of Tegucigalpa

United States Army Corps of Engineers

Universidad Politécnica de Ingeniería (UPI)

California State University, Chico (CSUC)

CSUC- and UPI- Student Teams

Project Partnership

Percent by Volume of Waste Components (Compacted)in La Ceiba, Honduras

4.9 + 1.5 + 12.2 + 24.8 = 43.4

Up to 43.4% Reduction in Waste Volume Landfilled

Recyclers play a valuable role in the solid waste disposal process

Benefits of the Recyclers Reduce cost to industries Reduce cost to government

(municipality) Increase environmental

sustainability

Risks to Recyclers

Exposure to the elements (rain, wind, sun)

Exposure to hazardous waste, such as lead, asbestos, blood, fecal matter, animal carcasses, broken glass, medical waste, & chemicals.

Exposure to diseases transmitted via insect and rodent vectors

High risk of tuberculosis, dysentery, parasites, asthma, bronchitis, helminths

High infant mortality rate Low life expectancies

More Risks

Proposed Communal Sanitation Facility Site

Source: Google Earth, 2009

Proposed Site

Water Requirements for Basic Human Needs

Estimated water demand for 300 recyclers at the Tegucigalpa Solid Waste Disposal Site:

18,000 L/month for drinking water180,000 L/month for laundry and bathing using a wash basin135,000 L/month for showers45,000 L/month for cooking/miscellaneous uses

Configuration Options

Evaluation of feasibility and design for:• Option 1: Showers, wash basins and pit latrines.

– Water demand: 495,000 L/month • Option 2: Wash basins and pit latrines.

– Water demand: 180,000 L/month • Option 3: Showers and pit latrines.

– Water demand: 270,000 L/month

Water Source Options

Stormwater collection

Continuous connection to municipal water supply

Controlled connection to municipal water supply

Connection to proximal groundwater well

Elevated water tanks

Ventilated Improved Pit Latrine

Source: Kalbermatten, 1982.

Emptying the Latrine Pits

Source: EPA, 2009

Human wastes and grey water disposal/treatment

Latrine/seepage pit Stabilization lagoons

Facultative Maturation

Use treated effluent for on-site dust control.

Sanitation Facility Design Proposal

Recomendations

To Minimize Water Requirements:

• Wash Basins - Landfill Operator or recycler will fill basins once daily.

• Organized leaders from the recyclers will charge for water usage.

• Recyclers will be allowed one 20 liter bucket per day for laundry and bathing, therefore No Showers.

• Water demand – 180,000L/Month

On- and Off-Site Reuse Materials for Building

Promoting Long-Term Project Success Provide sanitary facilities Provide identification,

recognition and registration of recyclers

Provide regular health care

Questions or Comments?