Report on Proposed Improvements for Water Supply and Wastewater Management on the Galapagos Islands

Third Draft

 

Amanda Morris, Erika Erickson, Aleksandra Hosa & Aleksandra Kopczynska 

November 28, 2004

 

I. Past Record

 

Few of the Galapagos Islands have fresh water, and those that do, get water from rainfall or groundwater.  Lack of water is a major social problem.  San Cristobal has a scarce supply but it is good quality because it comes from surface water.  During the dry months between August and January, it is known to have water shortages.  Santa Cruz is unique in that it has sufficient quantity of water to sustain its current human population of 10,000, but the water quality is problematic.  Water extracted from the well is affected by salt pollution.  Isabela has a limited water supply and poor water quality since it also is affected by seawater.  Leakages in water pipes add to contamination and stress on the water supply.  Over half the water carried through pipes in Santa Cruz and San Cristobal are lost due to leakages. 

The water needed each year in Santa Cruz (pop. 9,920), San Cristobal (pop. 5,682), and Isabela (pop. 1,474), and Floreana (pop. 88) are 724,160, 414,786, 107,602, and 6,424 m3 respectively.  Most of the water is imported.  The population is expected to continue to grow, calling for measures to conserve and improve water supply.

In the city of Puerto Ayora, Santa Cruz (Figure 1), the water is contaminated with bacteria because no sewer system exists and most residents dump their waste into two crevices that carry water to the city.  There have been several cholera outbreaks in the past as a result.  The sewer system in San Cristobal is outdated and in Isabela, although there is a new wastewater treatment plant and piping system to almost all homes, the piping system is contaminated.  About half the population has septic tanks.   

 

II. Proposed Improvements

 

a. Construct underground sewer system.

This is the best option for managing waste on the Galapagos Islands because it is the most reliable and efficient method for containing and transporting waste to a waste treatment facility.  We realized that such extensive construction could disrupt the sensitive ecosystem and explored another option of installing more septic tanks throughout the city.  However, further investigation showed that the number of septic tanks possible in a given area is limited by the drain field.  Too many septic tanks will cause too much drainage to occur in a given area, bringing about contamination.  We also found that it is possible to install a sewer system with minimal impact on the environment through the use of subsurface characterization and horizontal drilling.  Modern geophysical techniques based on the response of geomedia to various segments of the electromagnetic spectrum, seismic and/or acoustic fields, or other potential fields can detect the location of already existing subsurface structures, such as electrical wires and water pipes.  With this data, a route for sewage pipes can be easily chosen.  If houses are located both sides of the road, the ideal location for sewage pipes is in the center of the street.  The pipes connecting houses and the main should be about 4 inches in diameter, and the main should be 8 to 12 inches in diameter.  A typical material for sewer pipes is iron.  Manholes should be placed every 25 feet.

 

b. Upgrade monitoring and maintenance system of already installed septic tanks.

We suspect that the current septic tanks in the cities are neglected and only add to underground water contamination.  Therefore, they should be monitored and maintained more carefully and consistently.  Septic tanks must be emptied every three years, and the sludge transported to a wastewater treatment plant, where it is treated with woodchips and lime and converted into a nutrient-rich fertilizer.  An alternative is to replace the current septic tanks with more efficient ones that can break down material faster or with ones that do not self-drain; however, it makes more sense to extend the sewer system to houses with septic tanks and remove the tanks, instead of installing new septic tanks because the sewer system is a better system altogether. 

 

c. Construct wastewater treatment plant.

The Solar Aquatics System (SAS) is a wastewater treatment method well-suited to the Galapagos Islands cities.  It is capable of treating 22 to 4500 m3 per day, which serves 100 to 20,000 people, the rough population range on the Galapagos.  Isla Santa Cruz has approximately 10,000 people, San Cristobal has around 6,000 people, and Isabela has around 1,500 people.  Annual waste production in tons on Santa Cruz, San Cristobal, Isabela are 3,511.30, 1,286.35, and 284.61 respectively.  These numbers are expected to increase by around 50% by the year 2020.  Removal efficiencies for total suspended solids, BOD, and ammonia nitrogen are 99%, 99%, and 98% respectively.  It works by processing waste in self-adaptive aquatic environments housing plants, snails, bacteria, and other microorganisms.  These aquatic environments are contained in ten translucent tanks in a greenhouse, so they would not introduce any foreign species to the islands.  It can handle seasonal septic waste and has the potential for water reuse for irrigation.  The cost of construction would be about ___; however in the long term it is cost effective.  See Figure 2.

 

d. Implement system of water and sludge reuse through farming and irrigation.

Water reuse will conserve freshwater supply by making use of potentially large volume of lower quality water for irrigation.  More than 50% of the water consumed is directed toward agriculture.  On Isla Santa Cruz, this much water is the total consumption of water and this much water is used for farming.  On Isla San Cristobal, here are the figures.  Here are the figures for Isabela.  Recycling sludge as fertilizer has potential for increased crop yield because it is extremely rich in nutrients and will decrease need for chemical fertilizers.  Organic matter constitutes approximately 85% of all wastes produced in human settlements. At the moment only about 5% of solid wastes that households generate in the industrialized world is biologically digested to recover nutrients. Theoretically it is possible to use up to 85% of solid wastes as recyclable resource  (Niemczynowicz).  Disadvantages of water and sludge reuse on farms is that there is a potential health hazard in using lower quality water and sludge on crops that are not cooked before eaten, such as fruit or tomatoes.  Sludge should not be used on root plants such as carrots because these types of plants are particularly vulnerable to viruses not removed during wastewater treatment.  Cultural reasons may also prevent farmers from reusing wastewater on their land.  This is where education can play an important role.  Water cannot be reused if motor oil is present. 

 

e. Repair leaks in water pipes.

Because more than half of the water carried through pipes is lost due to leaks, sealing the leaks would conserve freshwater supply.  Modern geophysical technologies can help locate leaks in the pipes eliminating the need to physically disturb surface and subsurface structures.  Electromagnetic resistivity and ground penetrating radar are two techniques.  One method of electromagnetic reisistivity detects changes in electrical conductivity that occurs between subsurface zones, thereby detecting water leaks.  Once leaks have been located, localized repairs are then possible.  Several popular sealing grout mixtures can be employed.  Sealants such as Bentonite-Cement can be directed to stop a leak with a hydraulic conductivity of 10 to the (minus 7)/second.

 

f. Install corrugated rooftops, cisterns, and mini purification systems on all buildings for personal rainwater collection.  Construct larger cisterns on farms.

Household reservoirs would diminish amount of water drawn from municipal water supply and reduce pressure on water grid during peak consumption periods.  Personal reservoirs would be advantageous during dry months and water shortages.  Corrugated roof works by channeling rainwater to cistern, the size of which should be governed by amount of rainfall in that area.  Water purified by solar disinfection.  This system already in use in some areas - should be extended to more. 

 

g. Install meters on pipes carrying water into buildings to measure water intake. 

In order to provide incentive to decrease unnecessary water consumption, meters should be installed on water pipes carrying water into buildings.  These can also be installed in house basements.  People would then pay by the amount of water they consume rather than by a flat rate.  Currently on each islands, these are the rates they pay.  ADD FIGURES.

 

h. Increase education efforts to raise public awareness and support.

Reform plans will not be successful if people do not do their daily part to help conserve water and contain sewage.  Even with new sewer pipes and a wastewater treatment plant, the environment will still be polluted if people continue to throw trash onto the street.  Especially with a newly implemented system, education is necessary to teach people where to throw away their trash, how to reuse wastewater and sludge, and why it is important to conserve water.  If education has a positive effect on younger generations, the future will be in better hands.  

 

IV. Cost Estimate & Sources of Funding

 

The costs of constructing a sewer system and wastewater treatment plant and maintaining them are inevitably high, but because they are necessary for the sake of human health and environmental preservation, it should not be difficult to find support.  First, a cost estimate must be made by civil and/or environmental engineers.  Cost includes not only construction but also hiring of highly skilled operators.  Possible sources of funding are:

 

a. UNESCO

Environmental component of United Nations that may lend funds to assure wildlife preservation on Galapagos Islands, especially because the Galapagos is already on the UNESCO World Heritage List.

 

b. UNDP

United Nations Development Program is aimed toward helping nations increase long term sustainability.  Already working with Galapagos to develop renewable energy, preserve biodiversity, and develop economy.

 

c. World Bank, European Bank, European Union, Global Environmental Facility, International Maritime Organization

Already funding at least 20 Caribbean countries to develop waste management system.

 

d. ORGALA

Collection of NGO’s (designed by the Mission 2008 Las Iguanas political team) whose primary focus is to provide funds for sustainability and conservation projects on Galapagos Islands

 

III. Conclusion

 

It is necessary to implement a freshwater and wastewater management strategy.  Otherwise the quantity and quality of water will continue to deteriorate on the islands, which would have disastrous effects on wildlife and human health.  Although construction of a sewer system and wastewater treatment plant might seem expensive and temporarily inconvenient for the inhabitants, the long-term benefits far outweigh concerns.  The improvements we have recommended will decrease waste pollution, make water reuse a possibility, conserve the freshwater supply, and improve the overall quality of life in the human settlements.   

           

V. References

 

Assessment of Barrier Containment Technologies, U.S. Department of Energy and U.S. Environmental Protection Agency, Aug 1995.  Product of an International Containment Workshop.  Baltimore, MD, Aug 29-31, 1995.

 

“Growing Together: Our Local Sustainable Agriculture Program Continues to Achieve Success.”  Charles Darwin Foundation.  2001.  27 Nov 2004. http://www.darwinfoundation.org/social/ag2001.html

 

Hardenbergh, W. A. and Edward B. Rodie.  Water Supply and Waste Disposal.  Pennsylvania: International Textbook Company, 1963. 

 

Hollingsworth, A.  M.I.T. Environmental Engineering Major.  Interview.  2004. 

 

Ishizuka, Kozo, Shigeru Hisajima, and Darryl R.J. Macer, eds.  “Innovation of traditional and new technology to solve problems created by high technology.”  Traditional Technology for Environmental Conservation and Sustainable Development in the Asian-Pacific Region.  1996.  http://www.biol.tsukuba.ac.jp/~macer/TTEC/TTECFR.html

 

Koutsandreas, J.  Retired member of U.S. Environmental Protection Agency.  Interview.  26 Nov 2004.

 

Ley, Deborah.  “An Assessment of Energy and Water in the Galapagos Islands.”  Jul 2003.  http://galapagos.solarquest.com/documents/SandiaGalapagosReport200307.pdf

 

Maharaj, Utam S. and Tawari Tota-Maharaj.  “High-Risk Groundwater Development Option for Small Island Developing States (SIDS).”  Caribbean Water and Waste Association 10th Annual Conference.

 

“Management of wastes in small island developing States.”  Progress in the implementation of the programme of action for the sustainable development of small island developing States, Report of the Secretary-General – Addendum.  1998.  http://www.unep.ch/islands/dd98-7a2.htm

   

Niemczynowicz, Janusz.  “Innovation Trends in Urban Water Supply and Sanitation.”  http://www.iris.ba.cnr.it/sksb/Innovation%20Trends%20in%20Urban%20Water%20Supply%20and%20Sanitation.htm

 

“Programme of Action for the Sustainable Development of Small Island Developing States.”  UNEP Islands Web Site.  1994.  27 Nov 2004.  http://islands.unep.ch/dsidspoa.htm

 

“Puerto Ayora street map.”  www.TheBestofEcuador.com. http://www.thebestofecuador.com/map_payora.htm

 

“Solar Aquatics System (SAS) for Wastewater Purification.”  New Environmental Technologies Evaluation (NETE) Program.  http://www.ene.gov.on.ca/programs/3354e29.pdf

 

“Solar Aquatics System.”  OCETA Environmental Technology.  http://www.oceta.on.ca/profiles/earthtech/icon.html

 

United Nations Environmental Programme, South Pacific Applied Geoscience Commission.  “Source Book of Alternative Technologies for Freshwater Augmentation in Small Island Developing States.”  Small Island Water Information Network.  2002.  http://www.siwin.org/reviews/swr0004/swr0004b43.html

 

“Waste management.”  EUROPA Environment.  2003.  http://europa.eu.int/comm/environment/env-act5/chapt2-8.htm

Figure 1

 

Figure 2