Dominican Republic Point-of-use Water Purification Project Report

8/3/2019 Dominican Republic Point-of-use Water Purification Project Report

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Dominican Republic Point-of-use Water

Purification ProjectReport

BLUElabbetter living using engineering

l a b o r a t o r y

Spring, 2006

Prepared forManos A Tiempo (NGO)

Prepared by2006 BLUElab Dominican Republic Project Team

Jeffrey BorgesonDavid Dudek

Sanford Gifford

Manuel HernandezRobert PenfoldRyan RindlerEmily Yatch

John WhiteheadMarc Zawislak


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Report Outline

I) Executive SummaryII) Problem Identification

III) Stakeholder IdentificationIV) Work Contributed(A) Qualitative Testing on Drinking Water Samples(B) Workshop Presentations for Rancho al Medio(C) Arsenic Testing on Drinking Water Samples(D) Biosand Filtration(E) Identification of Appropriate Technology

V) IndicatorsVI) ConclusionsVII) Project Hand-off

VIII) Lessons LearnedIX) ReferencesX) Appendix

(A) Roles and Responsibilities of Team Members(B) Qualitative Testing on Drinking Water Samples(C) Workshop Presentation for Rancho al Medio(D) Arsenic Testing on Drinking Water Samples


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I) Executive Summary

Working with Health in Action (HIA) and Manos a Tiempo, our group set out to furtherelaborate and build from the achievements of last years ENGR 490 Dominican Republicgroup: the Clean Team. Our goals consisted of 1) the qualitative testing of primary

drinking water sources, 2) the development of educational programs for the community,and 3) further investigation into the most appropriate point-of-use water filtration methodfor the community of Rancho al Medio. Biological (e.g., fecal coliform) and heavy metal(e.g., arsenic) tests were conducted from samples taken from public and private wells, thenearby river and a local residents rainwater collection (all of which were used fordrinking). Educational programs consisted of presentations to the community-at-largeand community leaders. Ongoing research is being conducted into biosand filtration, aswe are in contact with Jim Bodenner (Founder: Safe Water Institute), who is in charge ofimplementing a biosand filtration project in the Dominican Republic. Our team isworking on forming a relationship with Mr. Bodenner that will us address the needs ofRancho al Medio, via our community partner, Manos A Tiempo.

The BLUElab DR Team traveled to the Dominican Republic (3/23/06 to 4/6/06) to carryout water testing and educational programs. The team also met with Andrea Pestone, aPeace Corps volunteer working with a nearby community who has implemented abiosand filter project in her own community.

Biological tests conducted in the Dominican Republic found high concentrations of fecalcoliform in the river. The arsenic testing was conducted in Michigan on samples collectedfrom the trip by using a mass spectrometer. All samples showed low traces of arsenic,which suggests that arsenic is not a likely cause of their poor health conditions.


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II) Problem Identification

Rancho al Medio is a small, underprivileged community in the Dominican Republic. It islocated southwest of the capital, Santo Domingo. This community faces many problemssuch as unreliable drinking water, unsafe water storage issues, and no effective household

water filtration processes. The communitys population is approximately 1500 and theunemployment rate is at 43%. However, of the 57% with a job, only 5% have a fixedincome and a mean monthly wage of RD$ 2,966 (< $100). Furthermore, considering thata typical household consists of five members and only one wage earner monthly incomeis only RD$593/capita (


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Secondary stakeholders may or may not be active in the project, but are affected by theoutcome of the project in one way or another. The University of Michigan has itsreputation and credibility at stake when a team of students, representing the university,carry out any external project. Local water distributors who currently provide potablewater to the community (e.g., water truck drivers, motorcycle couriers, and store owners)

may be impacted by this project, since their business may be jeopardized, and thus thisimpact should be mitigated. Potential local water filter fabricators have a businessopportunity, if the community is willing to pay for commercialized systems and have avested interest in this project. Gonca, S.A., a ceramics wholesaler with a workshop justoutside of Rancho al Medio has expressed interested in the research and development ofceramic filter systems, whereas the Association of Filter Makers (AFAFIL), localfabricators of biosand filters have expressed willingness to work with Manos A Tiempoto implement their technology in Rancho al Medio.

IV) Work Contributed

The source of self-reported health problems was investigated by the BLUElab team, aswell as the identification of an appropriate technology for water treatment, and increasedawareness of waterborne pathogens, illnesses, and safe water handling practices. Majorhealth complaints were addressed through the testing of drinking water samples in thecommunity. These tests took the form of qualitative (presence/absence) tests and heavymetals testing for arsenic using mass spectrometry. Unsafe water storage issues wereaddressed in educational workshops presented to Rancho al Medio. Household waterfiltration processes were also looked into during and after the trip to the DominicanRepublic.

(A) Qualitative Testing on Drinking Water Samples:

Testing of the drinking water in the community of Rancho al Medio is important ineducating the community members of the quality of their water supply. While in theDominican Republic qualitative testing in the form of presence/absence tests for theformation of hydrogen sulfide was performed. There is a presence of fecal coliform in thewater if hydrogen sulfide forms during these tests. If hydrogen sulfide forms in thesample there will be black precipitate and if the sample doesnt form hydrogen sulfidethen the sample will remain clear. These samples were taken to the education workshopsand shown to community members. This put a striking image in their minds and created avisual that meant the water they are drinking could be dangerous. Many communitymembers accompanied our team during collection of the water samples and this allowed

them to learn more about the testing and what we were doing.

Fecal coliforms are bacteria that live in the digestive tract of warm-blooded animals(humans, pets, farm animals, and wildlife) and are excreted in the feces. In themselves,fecal coliforms generally do not pose a danger to people or animals but they indicate thepresence of other disease-causing bacteria, such as those that cause typhoid, dysentery,hepatitis A, and cholera [1]. This is a concern for the community of Rancho al Mediobecause farm animals, such as cows and donkeys, travel to the river daily and care is not


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taken that these animals do not defecate in the river where drinking water is thencollected. It can also be a problem for rainwater collection or even the storage of water, ifleft outside with out a lid, because birds and small animals could become a danger to thesupply.

It was hypothesized that fecal coliform would be high in the river water compared to thewell and rainwater samples. It was also predicted that the river samples would be higherin fecal coliform concentration later in the day compared to in the morning, as well asdownstream in comparison to upstream. This was thought to be the result of higher usageof the river (e.g., livestock, water collection, bathing, swimming, and washing).

To prove the above hypotheses, samples were taken in the morning when we arrived andin the afternoon before we left. Samples were also gathered from many different sourcessuch as: the river, rainwater, wells, spring, and a private faucet. The river samples werealso taken upstream and downstream and both of these locations were taken mid-riverand at shoreline. The data collected from these tests support some of the hypothesis

stated above (Table 1 & 2), as the river and spring demonstrated the highest most probable number (MPN) of disease-causing pathogens, downstream locations, andafternoon samples had higher MPNs, on average,

Table 1. Qualitative Water Test Results, considering 9 different sources of drinking water in the

community of Rancho al Medio. Given a specific dilution factor and proportion of samples witha positive result (P/A Ratio), the most probable number of organisms per milliliter of water iscalculated (MPN).

Source

Dilution

Factor # Samples # Days P/A Ratio MPN

Well x 1 5 1 1.00 8

Rainwater 1 8 2 0.13 1

River 1 90 3 0.63 80Spring 1 5 1 1.00 8

Spring 10 5 1 0.80 80

Well 1 1 18 4 0.61 8

Well 2 1 2 1 1.00 8

Well 3 1 2 1 0.00 1

Well 4 1 5 1 0.00 1

Well 5 1 3 1 0.67 8

Table 2. Detailed Qualitative Water Results of the river (R), where DS denotes downstream, US:upstream, M: morning, and A:afternoon.

Source

#

Samples P/A Ratio MPNRDS,M,M 10 0.70 80

RDS,M,A 10 1.00 80

RDS,S,M 10 0.60 46

RDS,S,A 10 0.60 46

RUS,M,M 10 0.60 46

RUS,M,A 10 0.70 80

RUS,S,M 10 0.70 80

RUS,S,A 10 0.60 46


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(B) Workshop Presentation for Rancho al Medio:

To prepare for this years trip to the Dominican Republic an educational workshop on

drinking water was created to present to the community members of Rancho al Medio.This presentation contained information in the form of pictures, words, and props. It alsoused activities to engage the listeners in the workshop.

Some of the topics introduced in the presentation included: waterborne illnesses,rainwater collection, storage of drinking water, and filtration of water via SODIS (solarwater disinfection). These workshops were held daily for the duration of four days whilein the Dominican Republic. A final workshop was presented to leaders of the community.This workshop for the leaders allowed them to communicate their needs and concerns inan open setting. Time for feedback using surveys was also included at the end.

The presentation of this educational workshop for Rancho al Medio can be found inAppendix B.

(C) Arsenic Testing on Drinking Water Samples:

Heavy metal contamination in drinking water is a concern of all communities, especiallyunderdeveloped communities. Arsenic is found in the earths crust and enters waterthrough the dissolution of minerals and ore. This discovery of arsenic in groundwaterproved that well water could possibly be unsafe for drinking. Chronic arsenic poisoning,as occurs after long-term exposure to drinking water is very different to acute poisoning.Immediate symptoms on an acute poisoning typically include vomiting, oesophageal and

abdominal pain, and bloody rice water diarrhea. Long-term exposure to arsenic viadrinking water causes cancer of the skin, lungs, urinary bladder, and kidney as well asother skin changes such as pigmentation changes and thickening (hyperkeratosis) [2].Some of these acute symptoms such as diarrhea and abdominal pain were complaintsfrom the community of Rancho al Medio as found in last years survey conducted byBLUElab.

Drinking water samples brought back from Rancho al Medio during this years trip weretested for arsenic to determine if the symptoms mentioned above could be related to thearsenic concentration in their drinking water. Three main sources of drinking water weretested: a locals rainwater collection, a public well in the community, and the local river.

Thomas Yavaraski, a laboratory services supervisor from the Civil and EnvironmentalEngineering department of the University of Michigan, assisted our team inexperimentation using mass spectrometry to determine the arsenic concentration in thesesamples. A mass spectrum is a record of the relative abundances of a series of ions ofdifferent masses that form when a sample of a compound is bombarded by high-energyelectrons in a mass spectrometer. This bombardment causes an electron to be lost from amolecule of the compound, resulting in the formation of a radical-cation known as themolecular ion. The molecular ion fragments by the loss of radicals or neutral molecules


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to give positively charged ions. The mass spectrometer separates these cations accordingto their mass-to-charge ratios, m/z, and records their masses and their relative abundances[3]. Information regarding the testing of arsenic using mass spectrometry can be found inAppendix D. This appendix will include an equipment and materials list, the procedurefor the experimentation, the tabulated data, and a conclusion of the findings.

The World Health Organization (WHO) set a provisional guideline for the arsenic levelin drinking water at 0.01 mg/L. All samples tested from Rancho al Medio are safelybelow this level. The highest arsenic level was found in Well X water at 0.001971 mg/Land the lowest level of arsenic was found in a locals rainwater collection at -0.000107mg/L. Having the highest level of arsenic in the well attributes the generation of arsenicto the groundwater. This testing for the arsenic concentration using mass spectrometrysuggests that the arsenic content in the drinking water of Rancho al Medio is not a healthconcern to its community members.

(D) Biosand Filtration

Biosand is form of water filtration which treats water in multiple ways within a singleunit. Current biosand devices are typically a concrete box filled with sand and water.First the sand acts as a mechanical filter (similar to the clay filters) blocking largerchunks as well as cysts and worms. Next, predation: Micro-organisms living in the sandeat away at bacteria and other pathogens. Natural death: The pathogens trapped in thesand will not continue to infect the water due to a lack of food and un-ideal temperatures.Finally, absorption: Viruses attach to the grains of sand and are then inactivated by anti-viral chemicals produced by the organisms; some organic compounds are also absorbedby the sand. Additional treatment can easily be added, for example, a layer of nails addsiron, which bonds with arsenic (filtering it out).

Recently our group has been in contact with Jim Bodenner. He is not only the owner ofthe closest biosand filter to Ann Arbor, but he is also a major contributor to biosandprojects through out the Dominican Republic. Along with Rotary, over $300,000 USDhave been contributed and over 8,000 biosand filters have been placed throughout theDominican in the last 24 months. Recently his company received the exclusive patentrights for a more easily mass produced plastic biosand filter from the inventor of theoriginal biosand filter as well. We hope to form a better partnership with him to furtherour own capabilities.

(E) Identification of Appropriate Technology

The identification of the most appropriate water treatment technology for the communityof Rancho al Medio is of utmost importance. Using the technology selection toolintroduced by Robert Baffrey [4] and previously collected data of the Rancho al Mediocommunity (Appendix D), our team considered the role of drinking water source (e.g.,well, river, and water from a truck) and storage (e.g., open or semi-protected waterstorage). Results from this study suggested that SODIS offered the most appropriatetechnology for our community, based on their financial constraints, and that biosand


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filtration was the next best option for all considered conditions. In addition , a systematicanalysis of water purification technologies, based from the EWB Water ResourceGuidelines, the World Health Organization (WHO), and the Center for Disease Control(CDC), was conducted to compare the benefits and costs of additional technologies(Appendix D).

Table 3(a-d). Ranking for Household Water Treatment System technologies based on site-

specific and tech-specific factors. Scenarios considered include A) a composite source of waterwith open water storage, B) a composite source of water with semi-protected water storage, C)

the river with open water storage (worst case), and D) water from the truck with semi-protectedwater storage (best case).

A) Composite source of water with open water storageHousehold Chlorination 525 2

SODIS 610 1

Boiling 470 6

Ceramic Candle Filtration 500 5

Concrete BioSand Filtration 525 2

Combined Flocculation/Disinfection 510 4

B) Composite source of water with semi-protected water storageHousehold Chlorination 530 3

SODIS 615 1

Boiling 470 6




C) River with open water storageHousehold Chlorination 515 3

SODIS 600 1Boiling 460 6




D) Water from the truck with semi-protected water storageHousehold Chlorination 535 2

SODIS 615 1

Boiling 475 6





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V) Indicators

Indicators play an important role in a project like this. An indicator allows someone totell if what they are doing is having a positive or negative effect. The testing done on thedrinking water samples contained very easy to notice indicators. For instance, if the

drinking water of Rancho al Medio is contaminated with fecal coliform then the testsample will turn from clear to black. Also, if arsenic was present in the water therecording on the computer data acquisition program from the mass spectrometer wouldjump and you would notice a higher arsenic concentration.

Another indicator in this project was the displayed during the educational workshops presented in Rancho al Medio. During the final presentation to the leaders of thecommunity they were left with time for any comments or concerns. Some of the leadersalso had the chance to complete surveys that determined whether or not the workshopshad helped them and what they would like to see in the workshops. These were alsostraight forward indicators that allowed our team to know if these educational workshops

were successful.

VI) Conclusions

This project proved successful in solving the problems identified above. Testing of thedrinking water samples in Rancho al Medio addressed the health concerns of thecommunity. It was proven using mass spectrometry that arsenic is not present in asignificant amount to harm the drinking water. The samples tested were an order ofmagnitude lower than the provisional guideline for arsenic declared by the World HealthOrganization. It is recommended that further testing be done on the drinking watersamples brought back from the Dominican Republic. This is currently being started in theform of quantitative testing to determine the fecal coliform count in each water sample.

The educational workshops presented to community presented safe water storagesolutions. It also related their health issues to waterborne illnesses and introduced SODIS,a simple filtration system. While SODIS is simple and easy the wait for the water to bedisinfected can take 24 hours. This is a long time to wait considering the few minutes ittakes for a biosand filter to disinfect the water. It is recommended that biosand filtration be explored more deeply to determine if it is the right choice for household waterfiltration systems for the community of Rancho al Medio. A filter prototype, both durableand easy to use, should be developed, tested, and finalized using locally availablematerials, prior to traveling to the Dominican Republic.

There are many improvements next years team could make over our teams effort. Dueto inexperience, our ceramic filter development project was fairly unfocused andinefficient. Therefore, the 2007 team should clearly define specific goals for the projectand allow ample time for completion of seemingly small goals and tasks. It is ourrecommendation that the 2007 team develop a focused and detailed work plan completewith short-, mid-, and long-range goals.


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Following is a more specific set of recommendations for next years filter team:

1.) The 2007 team should conduct background research. The following websites will be helpful: http://www.potpaz.org/ and http://www.purifier.com.np/. Also, we

recommend that next years team set up a meeting with some team members fromthe 2006 project. Please contact Jeff Borgeson ([email protected]) or MannyHernandez ([email protected]).

2.) Based on the background research and any new ideas, next years team shouldgenerate detailed specifications for a ceramic filter apparatus.

3.) Next years team should rely on a pottery expert to fabricate the actual ceramicfilter element. It is not extremely difficult to fabricate the bucket and attachmentapparatus, but production of viable ceramic filter elements was difficult. Ourteam spent an incredible amount of time in the UM Art Schools pottery studio

trying to work with clay. It would have been far more efficient to generate adetailed technical drawing of the filter element, and then simply ask a willing pottery expert to fabricate it for us. John Leyland, the coordinator of UMs pottery studio, may be willing to do this. If not, he may know someone whowould be interesting in helping. His email is [email protected].

4.) After a preliminary filter has been fabricated, the 2007 team should ensure thatthe filter is durable and user friendly. A chief problem with the filters producedby our team was they exhibited a very powdery texture and crumbled very easily.The 2007 prototype should not have either of these characteristics. Also, the filterelement should be mated to the bucket/reservoir in a fashion that will allow theuser to refill the bucket with water without disrupting the designs efficiency. Forexample, the seal covering the interface between the filter element and the bucketshould not be destroyed when the user freely pours two or three gallons of waterinto the apparatus.

5.) The filter prototype should have a flowrate of 1-2 L/hr. Also, the filter shouldremove at least 90% of the bacteria found in the raw water. Quantitative testing procedures mentioned earlier in this report can be used to measure the filterefficiency of the prototype.

6.) During the troubleshooting process, next years team should contact experts.Obtaining focused and knowledgeable advice would streamline thetroubleshooting process. John Leyland ([email protected]) and Ron Rivera([email protected]) are two knowledgeable individuals. John Leyland doesnot have extensive experience with developing ceramic filters. However, he is thecoordinator of the pottery studio and has been very generous in providingmaterials and general advice on working with ceramics. Mr. Leyland also knowsother pottery experts who may have extensive experience with these filters: hemay be willing to help next years team get in touch with these people. Ron


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Rivera is a relief worker affiliated with Potters for Peace; he is involved with Nicaraguan potters who have experience producing these filters. Furthermore,there are many groups around the world working on these ceramic filter projects.Besides contacting Ron Rivera, our team did not make an enormous effort tocontact established pottery filter teams. We suggest that next years team attempt

to do this.

7.) There were two main concepts our team did not get the chance to investigate:colloidal silver coatings and die-casting filter production techniques. These aretwo things mentioned in other teams websites that we did not fully investigate.

VII) Project Hand-off

The tasks we have completed this semester have played a large role in the overall pictureof helping the drinking water problems in Rancho al Medio. The results of our work will

be used in the future involvement of BLUElab and future ENGR 490 teams to come. Ourteam hopes to document the CourseTools website that compiles our teams contributions.This will be a useful attribute for future teams working with the community.

Quantitative testing methods have also begun to be established, and should finalizedbefore the next field survey. Talks with Jim Bodenner are still pending, but should berealized in Fall 2006. If successful, implementation of biosand filtration could be aproject for BLUElab, Jim Bodenner, and Manos a Tiempo to arrange and implement nextyear.

VIII) Lessons LearnedDuring this project one lesson stood out the most. This lesson would be to be prepared forexperimentation and use extreme caution when doing it. While in Rancho al Medio ourteam was successful in completing qualitative testing but unsuccessful in completingquantitative testing, so the drinking water samples had to be brought back to campus withus for further testing. The quantitative testing was uncompleted because a hot water bathwas needed to incubate the samples. While in Rancho al Medio there wasnt a source ofelectricity to plug our water bath in. We tried to run it off a car battery, but found that itrequired more than just that. We needed a consistent source of electricity, so we movedthe laboratory to the hostile we were staying at. We soon realized that the electricity andwater are turned off during the day so we couldnt run the testing there either. Anotherproblem in the quantitative testing was the broth our team was using. We didnt receivethe new broth in time for departure to the Dominican Republic, so we were relying onbroth leftover from the testing done last year. This broth was unreliable and would yieldbad results. All of these problems could have been dealt with if the experimentation wasmore carefully planned. This could be accomplished if the experimentation was ranbefore departure to the Dominican Republic to make sure trial runs turned out the rightway.


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IX) References

[1] U.S. Environmental Protection Agency. 2006. Fecal Coliform. Available onlineat http://www.epa.gov/maia/html/fecal.html, accessed April 16, 2006.

[2] World Health Organization. 2001. Arsenic in Drinking Water. Available onlineat http://www.who.int/mediacentre/factsheets/fs210/en/, accessed April 3, 2006.

[3] Ege, Seyhan. 2004. Organic Chemistry Structure and Reactivity, 4. Boston,MA: Houghton Mifflin Company. 483.

[4] Baffrey, Robert. 2005. Development of Program Implementation, Evaluation,and Selection Tools for household Water Treatment and Safe Storage Systems in

Developing Countries. MIT.


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X) Appendix


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Appendix A

Qualitative Testing on Drinking Water Samples

Overview:

This appendix contains information regarding qualitative testing that was done ondrinking water samples while in Rancho al Medio. These qualitative tests were in theform of presence/absence test for hydrogen sulfide-producing bacteria such asSalmonella, Citrobacter, Proteus, Edwardsiella, and some species ofKlebsiella. Theseorganisms serve as a more reliable indicator of disease-producing organisms than E. coliin a tropical climate. Results from the hydrogen sulfide detection test are easy tointerpret. Black precipitate will be seen in the sample if hydrogen sulfide is present. Thesample will remain clear if hydrogen sulfide does not form. Included below are thematerials needed and methods.

Materials: Glass vials with screw-on cap Deionized water Water samples from Rancho al Medio Nutrient broth

Procedure:

10 mL of the water sample is added to the glass vial and then the nutrient broth is addedto the vial. The vial is then capped and shaken to dissolve the nutrient broth. This is

repeated for a 10X dilution of the water samples by adding 1 mL of the water sample tothe vial and then 9 mL of deionized water to the vial. This is also capped and shaken.

The samples are incubated at ambient temperature for twenty-four hours. After this timehas elapsed it is noted whether or not the sample has black precipitate present. These arerated 0 for a clear sample, 1 for a sample containing black precipitate, and 2 for a samplethat is all black.

A photo showing these different conditions is shown in the next section. The datacollected from this experiment is tabulated in an Excel format and can be referred to afterthis section.


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Photo Documentation:

This photo is described from left to right. The first three samples were taken from alocals rainwater collection and are rated 0 for a clear sample. The next two samples weretaken from well #1 and are rated 1 for black precipitate. The last two samples are takenfrom well #2 and are rated 2 for a black sample.


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Appendix B

Workshop Presentation for Rancho al Medio

Overview:

This appendix contains the presentation that was performed during workshops for thecommunity of Rancho al Medio. These workshops were conducted for four days(February 27, 2006 through March 2, 2006) during the time that we were in theDominican Republic this semester.

***Please see the separate attachment for this appendix labeled DR WorkshopPresentation.***


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Appendix C

Arsenic Testing on Drinking Water Samples

Overview:

This appendix contains information on the heavy metal testing done on drinking watersamples brought back from Rancho al Medio. The testing is specifically for arseniccontent in the water using a mass spectrometer. Included below are the equipment andmaterials list, procedure, raw data in the form of an Excel spreadsheet, and conclusion forthe experiment.

Equipment:

Mass spectrometer Computer with data acquisition program

Materials:

Deionized water Water samples from Rancho al Medio 1 ppb arsenic standard 10 ppb arsenic standard Ethanol Gallium

Procedure:

Deionized water is run as a blank sample to begin the experimentation. Once the massspectrometer tests the blank sample it sends the data to the computer program and thisprovides the laboratory technician with how much arsenic is in the sample. This creates azero base-line for all samples to be compared with. This also helps determine if thereare any deviations in the procedure or equipment by running the blank before, during, andafter all the samples. After the blank is run through the mass spectrometer it is followedby running the 1 ppb sample of arsenic and then the 10 ppb sample of arsenic. Runningthe blank, 1 ppb, and 10 ppb samples creates a calibration curve to plot where thesamples from Rancho al Medio will lie.

Ethanol and gallium are run through the mass spectrometer after each trial. The ethanolsterilizes the testing probe and tubing while the gallium normalizes the readings becauseover time the readings will tend to drift.

Test samples taken from a locals rainwater collection, the river that flows throughRancho al Medio, and well X are tested for arsenic through the mass spectrometer. Thesesamples are proceeded by a final run of the 1 ppb arsenic standard, the 10 ppb arsenicstandard, and finally the blank sample of deionized water.


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The data collected from the mass spectrometer is organized into an Excel spreadsheet forthis experiment that can be referred to after this section.

Excel Results for Arsenic Determination:

ARSENIC TESTING Conversions

WHO's Provisional Guideline: 0.01 mg/L (10 ppb) 1 mg/L = 1 ppm

1 ug/L = 1 ppb

Concentration Concentration 1 mg/L = 1000 ug/L

Sample (ppb) (mg/L)

1 ppb As 1 0.001

10 ppb As 10 0.01

10 ppb As 10 0.01

Rain Water -0.107 -0.000107

River Water 0.934 0.000934Well X Water 1.971 0.001971

Deionized Water -0.21 -0.00021

1 ppb As 1 0.001

10 ppb As 10 0.01

Conclusions:

The arsenic levels in the drinking water samples brought back from Rancho al Medio aregreatly lower than the provisional guideline level provided by the World HealthOrganization (WHO) set at 0.01 mg/L. The highest arsenic level was found in Well X

water at 0.001971 mg/L and the lowest level of arsenic was found in a locals rainwatercollection at -0.000107 mg/L (Note: The deionized water, which is presumably clean andarsenic free, read a level of -0.00021 mg/L. So, this negative number is actually usefuland shows that if the deionized water is taken to be arsenic free then the rain wateractually contains 0.000103 mg/L after subtracting the blank level from the rainwaterlevel.). This experimentation using mass spectrometry proved that the arsenic present inthe drinking water samples from Rancho al Medio is not of any safety concern to itsconsumers.


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Appendix D

Identification of Appropriate Technology

Overview:

This appendix contains information on the benefits and associated costs of a variety ofhousehold water purification technologies. It is a collection of data from a number ofsources, including the EWB Water Resource Guidelines, the World Health Organization(WHO), and the Center for Disease Control (CDC). Additional information is providedon waterborne pathogens and illnesses, chlorination and water storage containers to beused in unison with filtration technologies.

Figure 1. Comparative Assessment of Available Household Water Purification Technologies.

NOTES: Re:SODIS, key performance factors of SODIS include temperature and duration oftreatment; SODIS can be affected by UV absorbing solutes including microbes and by turbidity.

Most SODIS studies have been done for bacteria; bacteria can re-grow after 1-2 days of storage.Re:Bio-sand, many feel that this technology is less effective, acceptable and sustainable in

practice than in theory. Re: Chlorination, free chlorine provides a residual effect. Re: All

ceramic filters, systems can remove helminthes and protozoa mechanically, as well as largesediment. Re: boiling water, bacteria can re-grow after 1-2 days of storage, biggest disadvantage

is fuel source and time. Re: U-V Radiation, U-V-Radiation systems are extremely fast andeffective, but expensive and require electricity. Re: black bottle system, achieves high enough

temperatures for viruses, less affected by turbidity, but requires cooker or collector. Re: plainsedimentation methods, these are seen as pretreatment, can remove large microbes (helminthesand some protozoa), solids. Re: fabric filter, can remove many helminthes, large sediment.

Cost materials

Locally

available? maintenance life indicators of wear Flow Rate

Minimum

Mechanical

Filtration size

Disinfe

effectiv

SODIS Cost of PopPET Bottle, shape and size

matter, 1.5 L optimal Yes

clean bottles, aeratewater, monitor fortmax and duration

until bottlesscratched Scratches

2liters/bottle/6hoursif sunny none

moderate wsun, should

Bio-sand US$10 - US$30 Concrete, Sand NoYes, but no

Replacable Parts Forever

no growth layer,physical

degredation of filterencasement 60 Liters/hour microns

Low, aroundbe as high

Chlorinating water

Cost of Chlorine? Howmuch do they have to

buy?Chlorine tablets, liquid,

powder, or gas Yes

No, is there an easierindicator for testing for

residueOne

Drinkingcontainer

discoloration10-20 minutes per

treatment none hig

Potters for Peace US$7-US$10 in D.R.Clay, Saw Dust, and

Bucket/Spout Yes ~1 Year cracks, film growth,

clogged 1-1.75 Liters/hour microns

moderatedepending o

filt

Potters for Peace with

film

US$7-US$10 in D.R. PlusCost of Silver

Clay , Saw Dust, CollodialSilver, and Bucket/Spout No

cracks, film growth,clogged microns

moderatedepending o

filt

ndle or other Ceramic

Filter Clay & Saw Dust Yes ~1 Year cracks, film growth,

clogged 1-4 Liters/hour microns

moderatedepending o

filt

Ceramic Filter withactive carbon

Clay, Saw Dust, and ActiveCarbon Filter No


moderatedepending o

filt

eramic Filter with filmor other compound ?


moderatedepending o

filtBoiling water energy used to boil fuel for heat, pan for water limited Life of pan 6 L/hour none hig

U-V radiation quite high Controlled U-V source No none hig

Black bottle system solar cooker ? 1.5 hours per batch none HigPlain Sedimentation Yes Lo

Fabric filter Yes low


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Table1. List of waterborne pathogens and relevant characteristics.


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Table 2. Typical contaminants of drinking water. NOTE: The filtration size required for

helminthes is 1 mm, and the highest number of cases are reported in the tropics and subtropics.Protists are reported worldwide, and symptoms include severe diarrhea, abdominal cramps,bloating, fatigue and weight loss. Protists can also form cysts resistant to chemicals so must be

removed mechanically. Bacteria can live for weeks on surface water; and require the use of

microfiltration or disinfection. Viruses can't be completely removed by micro filtration; normally

disinfection is used, but many have shown resistance to chlorination. A number of authors nowsuggest that Norwalk virus and Norwalk-like viruses are the major causes of both food andwaterborne illnesses worldwide, including 6.5 million annual cases of waterborne viral disease inthe United States alone.

Size (bacte

or eggs andlarvae

elminths round worms tape worms Guinea worm blood flukes many more 0.01mm

otists Giardia lamblia Cryptosporidium

Cyclospora

cayetanensis 1-100micro

cteria

typhoid

(Salmonella

typhi), paratyphoid (Salmonella paratyphi-A),cholera (Vibrio

cholerae).

campylobacter

enteritis

(Campylobacter

jejuni)

bacillary

dysentery

(Shigella spp.),

salmonellosis and

enteric fever

(Salmonella

leptospirosis

(Leptospira) 0.2 micron

ruses Hepatitis A, rotaviruses enteroviruses Echovirus poliovirus Hepatitis E 0.004 micro

rganic

mpounds Benzene Carbon tetrachloride

many more

see EWB

paper

organic

mpounds

Naturally

occurring:

Arsenic, Barium, Boron, Chromium, Flouride,Manganese, Molybdenum, Selenium,

Uranium, Cadmium, Cyanide, Mercury

Industrial

Sources andhuman

dwellings:

Cadmium,Cyanide,

Mercury

Agricultural

Activities: Nitrate, Nitrite Pesticides:

Alochlor,Aldicarb, an

many more

Typical contaminants of drinking water


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Table 3. Preparation of 1 L of 1% chlorine solution.


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Table 4. Alternative Household Water Storage Vessels: Advantage and Disadvantages of

Different Designs and Materials.

*Oxfam vessel is used primarily for emergency water storage and delivery. But, vessels ofsimilar size and shape have been used for household water collection and storage worldwide.

Documents

Dominican Republic Point-of-use Water Purification Project Report