Packing List #1

Christmas Eve. Ten days until departure. Most of the large problems worked out well enough for comfort. Plane reservations for the group and hotel acommodations for me and Gail are all made. Its a little too early to actually start packing but its a good idea to be getting things ready. My biggest contribution to the group is a very well provisioned first aid kit and the ability to use it. I replaced and expanded the kit after return last time so that is pretty much set. All it needs is a quick recheck to make sure nothing is outdated. There are a few items that experience taught me is good to have along and I will periodically share them over the next week.

1. Cheap, light plastic rain ponchos. 2 or 3 of them; keep one in my backpack
2. Small nautical pulleys (3). Useful for raising items.
3. Thin nylon cord for #2
4. AAA batteries
5. Freeze dried ice cream - treat for students. Last years group had never heard of it and didn't believe me
    until I gave them some.
6. Spoon/knife eating utensil
7. Crazy glue
8. Assorted zip lock plastic bags

I will post more as I think of things.

Had a nice train ride Tuesday with Frank Sokolowski. He was heading home to Philadelphia from Rensselaer so I boarded the train in Rhinecliff and traveled down to New York City with him. We tested the Hach colorimeter that he got from the campus store room. It is quite a bit more sophisticated than my unit and can measure numerous different analytes whereas mine is exclusively for chlorine.We actually sat on board the train measuring water samples. The two meters agreed nicely and are both easy to use. All in all it was a fun trip. We hung out in Penn Station for a half hour then I boarded the next northbound train and headed back home.

Answers - Finally!

With the arrival of the Hach Colorimeter I was finally able to get good quality data and make some solid conclusions. Here's what it looks like: The meter itself is the black device that looks like a TV remote clicker. To it's right is a container of 5-in-1 test strips.

I did some practice runs on tap water from my home which is well derived and free of any baseline chlorine by making a 1:10 bleach dilution which allowed me use much smaller source volumes, everything scaled back by factors of 10: instead of 6 ml of undiluted bleach in 55 gallons I could do 0.6 ml of the 1:10 dilution into 0.55 gallons of water and get the same concentrations. Using the test strips I could get an idea if we really were in the ballpark range. Here are the results:

5 in 1 Dipstick Measurements done on well water using 1:10 bleach dilution in 0.55 gallons water
Bleach (0.825%) ml			Total Cl (ppm)		Free Cl (ppm)
Trial 1
0.5			1		0
0.6			2		0.5
0.7			4		0.5
0.8			4 to 10		1 to 2
0.9			4		0.5
1			4		1
Trial 2
0.5			2		0.5
0.6			4		1
0.7			4		1
0.8			4		1
0.9			4 to 10		1 to 2
1			<10		4

So, based on dipstick values we are pretty good in terms of being in the range. The problem with the dipstick is that they are a "blunt instrument". Rather than giving you a reliable numerical measurement the strips basically tell you one of three things: "none/not enough", "enough" or "too much". A good start for estimating but lacking in finesse. Enter the colorimeter. It works by detecting the absorption of light at a wavelength of 528nm. To perform the test water is mixed with a small pre-measured packet of DPD (dietheyl-phenylenediamene) powder; if chlorine is present it reacts to turn the solution pink.

The meter then reads the strength of absorption proportional to the amount of chlorine present. We get a number. A real quantitative value that can be used to generate data, produce equations and make predictions.

 

The challenge with the meter is that, as usual, the devil lies in the details. Every time you draw up a sample from a different source or strength, everything has to be thoroughly cleaned with tap water (sample cups, measuring tubes, syringes for drawing up, etc). So, even a few relatively simple measurements can chew up an hour or too pretty easily. Now add in going in and out to add increments of bleach to the barrel, letting it mix for 20-30 minutes with the occasional stir, siphoning out samples, labeling the jars plus doing the measurements and you can lose an entire afternoon really fast! Anyways, I was able to squeeze a few hours together yesterday and did just that. Here are the results:

Colorimeter Measurements			55 Gallon Barrel		Dipstick Measurements			55 Gallon Barrel
Bleach (8.25%) ml			Total Cl (ppm)		Total Cl (ppm)		Free Cl (ppm)
Trial 1
0			0.01		0		0
5	0.85		0.85		0		0
6	1.4		1.4		0.5		0
7	1.77		1.77		0.5		0
8	1.58	*	1.58	*	0	*	0	*
9	2.2		2.2		0.5		0
10	2.2		2.2		0.5		0
11	2.2		2.2		1		0.5
12	2.2		2.2		1		0.5

 

However, note that the value for 8 ml is a statistical outlier leading to some inaccuracy in the linear equation. If we drop that value we get a better estimate of the line and a different equation.

This improved data and equation now allow us to confidently plug in any amount or volume of bleach we may want to add to the 55 gallon drum and come up with a reliable concentration of chlorine remaining in the water, and it should stand up to measurement with the colorimeter. Here is a table of such a prediction. So, if the WHO established chlorine level is 2.5 mg/L (PPM) then a dose of somewhere between 9 and 10 ml of 8.25% bleach will reliably produce that level. But, there is a catch: Every different source water will have it's own unique chlorine requirement so that the values I have established for rainwater in Hurley, NY may be very different, from say, water taken from the Gowanus Canal in Brooklyn, NY. This is called "chlorine demand" and means that one of the first things we will need to do in Panama, in tandem with installing the new tanks, is to set up a barrel and starting testing to establish what the chlorine demand is for their source water (rain) and make up a table for them to use once the system is up and running. Still, this gives us a good idea of the variability of chlorine dosing and the fact that untested calculations alone are not enough. Very satisfying.

Table based on equation Y=0.3263x-0.6474 5 0.9841 6 1.3104 7 1.6367 8 1.963 9 2.2893 10 2.6156 11 2.9419 12 3.2682 13 3.5945 14 3.9208 15 4.2471

Things Are Never as Easy as They Seem

Less than three and a half weeks until we leave and we still have not established the correct bleach dose. I have been using 60 ml plastic specimen containers to collect the water and then bringing it up to the lab at RPI. I have usually done the dosing and sampling the day before so that the samples have sat for 24 or more hours in the containers before being tested. Last week I had done the bleach dosing on Tuesday then went up to campus on Wednesday night and we ran the levels using dipsticks. The effective dose seemed between 12 and 15 ml per barrel and we were hoping to confirm this using a colorimeter. Chip and Frank found the one in the basement and I ordered a used on on Ebay (as well as reagent kits for it and several bottles of 5-in-1 test strips). Frank went back a couple of days later and rechecked the levels. The previously robust sample ranges (12-15 ml) were now reading zero. This can be explained by either adsorption of chlorine to the plastic or reactivity of the chlorine (oxidation) with the plastic itself. Given the 24 hour delay between sampling time and testing, this calls into question the validity of these ranges. It may be much lower bleach dose is needed and that means we need to do more testing.

The new plan involves a two-arm experimental plan: One is a real time dose-titration, the other a time-stability study. Now that I have all of the necessary equipment at my house I can test immediately after I have made each dose titration. I will start at the 6 ml of 8.25% bleach, do a fresh sample using both dipstick and colorimeter and then pull off two samples - one stored in plastic and the other stored in glass (these are for the time-stability portion). I can add bleach in any increment I choose then add smaller increments as I start to get readings on either dipstick or colorimeter until I get overshoot. Hopefully, once and for all, this will give us the best correct bleach dose. Once that portion is complete I can then do a daily check on the stored plastic and glass container samples to see if the chlorine degrades faster in the plastic containers.If there is degradation of chlorine level I don't know if this data will be sufficient to distinguish the mechanism between adsorption to the sides of the container versus oxidation of the plastic by the chlorine. That would be a function of the reaction rate kinetics. Chip can hopefully shed some light on that aspect.

I have picked up two more 55 gallon drums to hook to the downgutters so I have enough water to repeat tests if I need to. Fortunately, I don't anticipate much packing as most stuff is all packed up neatly from last year. As soon as I get some of the testing done (hopefully Sunday afternoon) I will post the results here. Lastly, it looks like my loyal reading base in South Korea has been looking in. I wish you all gyejeol-ui insa. I am trying to say "Seasons Greetings" and I am totally depending on Google Translate for this. If am wrong, please, someone correct me and let me know the correct way to say it. Also, there seems to be a bunch of folks in Russia reading; to all of you I send sezony privetstviya. Again, if wrong, please me a comment and correct me.

Third Times a Charm

Following the first two sets of rainwater tests, we really did not have a great sense of the correct bleach dose for a 55 gallon barrel. The calculated amount of 5.8 ml (let's just call it 6 ml, please) was insufficient and did not register on the chlorine test strips at all; the 58 ml (a 10x strength) overshot the mark by a bit; and the 580 ml (100x) was way off the scale. A crude series of 50%-50% volume dilutions indicated that the correct dose lay somewhere between, say, 9 ml (1.5x) and 18 ml (3x). We needed at least one more trial to fine tune the dosing and my concern was that, with little more than a month until we travel, we would not get sufficient rain for one more refill of the barrel before winter and snow set in. Fortunately, the weather is cooperating. The barrel is full and I am in the process of making a series of chlorine solutions  starting with our calculated 6 ml dose and increasing it by 3 ml increments through 18 ml. I have collected samples up through 12 ml; the 15 ml dose is equilibrating and is due to be sampled in 5 minutes. Then the last solution will be 18 ml of bleach and that range of specimens ought to capture the final free chlorine target dose of 2.5 mg/L (or ppm) as specified by the World Health Organization. I will bring the samples up to campus tomorrow during the weekly meeting and Frank, Kyra and Jonathan can test them. We are also looking at a small Hach colorimeter that would provide more accurate measurements and I have located one on Ebay at a reasonable price.

More Partially Explained

I ferried the water samples up to RPI and met Frank, Kyra and Jonathan at the MRC lab and we headed down to the basement where the EWB chapter has been granted some primo real estate. That is sarcasm. The place kind of reminds me of being backstage at some very old theater - rooms sectioned off by lumber and fencing and such. All kind of creepy. Anyways, this is where we had the testing equipment stored so it would have to do. I will spare the boring details and cut to the chase. After checking the 4 different specimens (0, 1x, 10x and 100x) it looked like 1x was not enough but 10x was too strong; by making serial dilutions we were able to get a rough idea that our bleach doses needed to be 1.25 to 2.5 times larger than we had calculated. Much better than my original 100 fold estimate of error and fairly close to being within the ballpark.

Had a long talk with Chip Kilduff on the drive home and we both agreed that the main value here is: 1. We will definitely need to carry out  same determinations as soon as we get the system set up on the island; and 2. That we will need to have a number of different dosing tables for a range of chlorine doses pre-made and select those best suited to the chlorine demands imposed by the islands water. Fine tuning this will require at least one more set of rainwater tests and I have already started the siphon to drain the barrel and reconnected the diverter hose. Once the next rain comes I will repeat the tests using bleach strengths of 1x (5.8 ml bleach per drum), 1.5 x, 2x, 2.5x, 3x maybe up through 5x (29 ml per drum). With this info we can generate dosing charts and be ready to go.

Very satisfying - all in a days work.

Lastly, a big hello to everyone in South Korea reading this - I hope you are enjoying it and hope the English slang expressions I use are not too confusing. Yell if you need help.

Partially Explained

As I laid in out in yesterdays posting I have (so far) taken samples from the barrel with no bleach, 5.8 ml of bleach and 58 ml of bleach; currently the barrel has been dosed up to the max of 580 ml of bleach and it is equilibrating. I tested the samples of the first three doses with the high sensitivity/low threshold dipsticks from dialysis. My prediction was that it would be pointless to even test the maximal dose as the threshold should be met or exceeded by the third sample (58 ml or ten times our predicted dose). The samples behaved as predicted.

The level that dose our calculation was predicted to produce was 2.5 mg/L; this batch again shows it somewhere in the range of 0.02 - 0.05 mg/L or 1/100th of expected. When the bleach dose was increased tenfold (58 ml in the barrel) the threshold of the test strips, 0.2 mg/L, was exceeded (as predicted). I bet that using different scaled strips it would fall somewhere in then range of 0.2-0.5 mg/L. The whole thing is off by 100 fold and I have a feeling it has something to do with the base assumption of the bleach strength expressed as a % (ie, 8.25%). Our calculations are based on the assumption that 8.25% means 8.25 grams of Sodium hypochlorite in 100 grams of water. This may be an incorrect assumption. However, in the absence of a better explanation the new empiric value rules and it would work out to something on the order of either ~ cups of 8.25% or ~3 cups of 5.25% bleach per 55 gallon drum.

I will finish up the last set of samples (580 ml - which should yield the target range of 2.5 mg/L) and cart them up to Frank for definitive testing. I also have a 4 gallon tank (blue) of untreated rainwater for him to use in anything he sees fit.

If anyone reading this finds it tedious, I apologize. Just thought you might want to know...

More Glitch

I have not been able to reconcile the discrepancy between the negative results obtained from the rainwater samples and our calculations. I checked with Frank and he ran the samples promptly.To try to get better insight into the problem I went down to the dialysis unit and spoke with Joey Schoonmaker, the water technician for the unit. He is, literally, a walking encyclopedia with regards to the water treatment system in the dialysis unit. He provided me with a pretty quick and in-depth overview of how the water is processed before it is safely utilized in the dialysis process for patients. Unlike our need for chlorination theirs is the exact opposite - they want no chlorine in the water being used for dialysis so they test for chlorine residuals at the lowest end of the spectrum. Still, the test strips they use could be used to at least let me know if our dosing discrepancy was a fluke or a reproducible error. Unfortunately, it appears to be the latter.

Joey gave me a handful of test strips to bring home and I set up a counter top chemistry lab.

 In the photo below the actual unused test strip is at the lower left and the chart for interpreting values is in the center of the photo. If you can make out the markings, from left to right, as the colored ovals progress from yellow to blue, the values go from 0 to 0.2 mg/L. The World Health Organization set 2.5 mg/L as the target level for chlorine residuals in treated water.

 

The fact that these test strips are off by one full order of magnitude does not render them useless. For starters, I can mix a batch of rainwater on a smaller scale to the same concentration as I would in the barrel, just scaling back the amount I add proportional to the size of the batch I am making then test. If our calculations are correct, and there are no other errors in either our assumptions or our methods, then the sample should overshoot the test strip and it should turn it dark blue. Bad if we are doing dialysis; good if we are disinfecting water for drinking purposes. So, following this reasoning, I mixed up a fresh batch of water, using a TB syringe to add 0.15 ml of 8.25% bleach to 2.65 L of water. This mixture is actually rather rich and should produce a chlorine level of between 4 and 5 mg/L. After letting it stand for a few minutes I

lowered in the dipstick, swirled it a bit, drew it out and read the results. Take a look.

The reading should be a robust blue of a shade equal to, or darker, than the last oval on the right. As you can see, it clearly is not. It reads right on 0.05 mg/L. What is interesting about this error is that it is numerically correct, only that it is off by two orders of magnitude (factor of 100x). This leads me to believe that somewhere in the calculations is a unit conversion error, but I will be damned if I can find it. I have re-run the numbers more than once and don't see it.

On the up side, though, is that I have a plan for tomorrow. I will first add 5.8 ml of bleach to the barrel and take samples; then I will add another 52 ml (for a total of 58 ml) or 10 times as much and take samples; then finally, I will add 520 ml of bleach (for a total of ~580 ml of bleach) or 100 times as much and again sample. If it is simply a unit conversion error in our calculations this should reveal it. I am, however, leery about this as it would entail adding a liter of bleach to every 55 gallon drum. This seems to fly in the face of more conventional doses that I have found online at the WHO and other websites that start with 1% stock solutions and add amounts on the order of 20 ml to a 45 gallon drum. Something just is not adding up and we need to rectify it quickly.

Glitch

Okay. On Tuesday I reported here on the sample chlorination using rainwater that I did last Saturday. I traded emails with Frank Sokolowski who ran the samples and none of them showed any chlorine residual at all (neither free nor total). It's a good thing I refilled the barrel on yesterdays rainfall as we definitely need to do it again. Here is the error analysis I submitted to Frank.

Error Analysis – Potential Sources

1.       I have rechecked our calculations to make sure there are no unit conversion errors. I can find none and both of our calculations were performed independently and agree.

2.       The bleach I used was of uncertain age. It certainly wasn’t new. Loss of efficacy? Seems unlikely, but I will buy new bleach.

3.       Chlorine consumption/decomposition due to delay in testing? I don’t know when you did the testing and how long the samples sat. Chip Kilduff can shed some light on the time dependent aspect of chlorine degradation.

4.       Routine chlorine demand of rainwater at my house exceeds our calculations. Again, Chip is our resource.

 So, the plan is to repeat the procedure on Sunday with a bottle of new bleach and bring the samples directly up to Frank for prompt testing to eliminate those factors. I will also bring up a 4 gallon tank of untreated rainwater for Frank to use. I'll make a point to throw in some photos then. We shall see.

On another note, the blogs administrative area includes a statistics section that provides me with various breakdowns of readership. Over the past two weeks there has been a bit of a surge in views from South Korea and Japan. Now, I have no idea why folks over there would have any interest in this blog but I certainly want to reach out and say "annyeonghaseo" and "kon'nichiwa". God bless Google Translate, that's all I can say. Thanks for reading and I hope I don't bore you. Who knows, maybe you need this for some class project or something.

Rainwater Samples

So it finally rained last week. Even though it was not a downpour I was amazed at how quickly the barrel filled. It really is an excellent example of how large the volume of rain runoff is from a non-absorptive surface (the problem with flooding from shopping mall parking lots, etc). So, anyway, it probably filled somewhere around Tuesday or Wednesday. Saturday morning I siphoned off 5 samples of unchlorinated rainwater to use as the control blank (always use an odd number so there is no chance of a "tie") for background chlorine levels or for microbial cultures. Then it was time for bleach. Now, we based the majority of our calculations on what we thought was the most common strength of commercial bleach, sodium hypochlorite 5.25%. The store shelves now also carry "concentrated" bleach of 8.25%. We did do a table of calculations using this strength just in case. So, on Saturday morning, I look under my cabinet at my bleach - all of it is 8.25%. Figuring I really want to do this as close as to what we will be doing down in Panama I went down to Hannaford to try to find some 5.25% stuff. Good luck with that - every last bottle was 8.25%. Oh well, you gottta work with what you got, so, back home. I drained the barrel down exactly to the 55 gallon mark and added the bleach. The volume of bleach is quite minuscule - 5.8 ml or slightly more than a half a teaspoon full - and you don't just squirt it in directly. The correct procedure is to siphon off a half gallon or so from the barrel then add the 5.8 ml of bleach to that, thoroughly shake it around, then add that solution to the main barrel. All of this was done just so; I left it to sit for 45 minutes then went out and stirred it for several minutes with a broomstick and let it sit for 45 more minutes. Finally, 5 more samples were drawn off, capped and placed in specimen bags. Delivered to Mike Saturday night, then went to the hockey game. Yesterday, I drained and rinsed the barrel and set it up again to wait for the next rain in case we need to repeat the test.

Now, all we do is wait for the results which I will post as soon as I get my hot little hands on them. Fascinating stuff, huh? Science really is like this.

The New Team

As I previously wrote, the preliminary team was Me (Assistant Construction Lead) and Chip Kilduff (Quality Assurance Lead) as mentors, with Mike Kubista as student project lead and 4 students to be added. The final lineup has been announced and here's how it looks:

Mariana Cintron - Translator
Elizabeth Kwon - PMEL Lead
Mike Kubista - Construction Lead
Tim Andrews - Assistant Construction Lead
Frank Sokolowski - Education Lead

January 4th is less than two months away. For me it means getting through the holidays and taking the extra on-call so I can be away for much of January. Much less packing as most of my stuff from last year was neatly stored away for easy use; all the first aid kit was restocked. For the students it means the last 6 weeks of the semester with finals and all of the stuff that comes with being a student.

On the plus side, I am going back a veteran and have a much clearer view of the things I would like to do. The scope of the project is smaller and should require a little less of the hands on that I gave last year. I want to take lots more photos and get them posted up to the blog really quickly this time - none of this after the fact stuff. I really want to spend more time with the people in the community and get to know them better and have a little fun with them. I would like to try to get them to understand the value of clean drinking water and improved hygiene but I don't have a clear plan for that as of yet. We should definitely challenge them to volleyball.

It is gently raining out now and the experimental tank is slowly filling - hopefully by the morning it will be full and I can dose it with bleach and mix. We'll see how good those paper calculations turn out!

The Hurley Rainwater Research Center

Last week it occurred to me that, while we have carefully done the calculations to determine the amount of bleach to be added to each 55 gallon drum to achieve a level of chlorine that will kill bacteria yet not leave an unpleasant taste (WHO  recommends 2.5 mg/liter, US EPA less than 4 mg/liter) it might be nice to see if our calculations are on the mark. Not only would it validate our calculations it would give us experience using the system and doing real-world chlorine residual tests. I ran it by the major honchos (Mike, Frank and Chip) and all thought it was a pretty good idea. Chip also added that different water sources pose different chlorine demands depending on level of bacterial contamination. I figured I was in a pretty good position to at least do a rainwater sample as my downgutters are equipped with diverters for rain barrels. Borrowing an empty 55 gallon drum from dialysis (and thoroughly rinsing it out) the Hurley Rainfall Research Center was born. Following the next sizable rain the protocol states to add 9.1 ml of regular strength (5.25%) commercial bleach to the barrel.

Now, to wait for the next rain event. Unfortunately, according to the National Weather Service we are looking clear for the next 5-7 days. I'm sure it will rain sometime between now and January.

Footwear, found.

I knew they had to exist somewhere. Of course, LL Bean. Bean Signature Maine 10" Hunting Boots. Standard "Duck Shoe" bottoms with a lightweight waxed canvas upper. I think they should be perfect.

I love that the upper can be completely folded down into the body of the shoe so it doesn't kill me for space in my duffel bag. They lace up nice and securely so that the mud won't pull them off and hopefully, my feet will stay dry. The basic design dates to 1912 so there's over 100 years of experience here.

Snakes and Lanterns

Had dinner with Chip and his wife, my former classmate Marie and her fiance Steven, and Gail up at New World Bistro in Albany followed by hockey at RPI. Nice night and good chance to talk to Chip about the trip and the plans going forward. Both of us have been heavily involved in most of the development aspects of the project, but there was one place in which we diverged a bit. As a newcomer to this type of thing I am a bit compulsive about doing everything according to the book. As a veteran, Chip is able to be a little less rigid than I. In reviewing the 525 document prior to it's submission I read every word of every page. OK, not such a big deal, 65 pages more or less. Executive summary of the project to date, rationale for expansion of water treatment, plans for implementation, design drawings, reams of calculations, budget for trip, so on and so forth. Not exactly Hemingway but, if it's in that document and I sign off on, it's the same as if I wrote it. Except one little hitch: The 525 itself does not include the HASP. Yes, the HASP,  the "Health And Safety Plan" document. This one is 92 or so pages. It includes the designation of a H & S officer, the location of the nearest hospital from the Island (as well as the length of time it would take to get there), an inventory of any dangerous equipment or materials to be used, necessary protective equipment ("PPE's" or "PeePees" as I was taught), the suggested vaccines we should get (most of which I disagreed with) and other things relevant to our safety. All of this jazz occupied 30 or so pages. The other 60 pages was a compendium of the venomous reptiles, insect and fish that have ever been found in, or around, Panama. Each page had a color photo of the offending creature, its habits, its habitats, the type of venom it inflicts, and how gruesome one's death will be after the bite or sting. It reminded me of two things. The first were those really neat, old-fashioned books about exotic animals in faraway places I used to read as a kid, the ones where the photographs were pretty scarce and were referred to as "Color Plates". Remember those? Cobras, Coral Snakes, Banded Kraits (rhymes with 'kites'), Pacific Sea Snakes and of course Fer-De-Lances.

The second is the old joke about the cowboy who gets bit on a certain part of his anatomy by a rattlesnake. The punchline is "Tex, yer gonna die". I told it to the students on the island last year. Figure it out for yourself. Anyway, Panama sure seems loaded with poisonous creatures.

On a different note, one of the big draws about a trip like this is that it is a wonderful excuse to buy a few new pieces of travel gear. This sort of a camping trip on steroids (and snake venom). This years new gadget is the "Lighthouse 250" solar charged lantern put out by GoalZero, the folks who make the portable solar panel and storage battery that I use.

The lantern is a pair of independently controlled LEDs, one in front, one in back with variable brightness. Charging time by solar is 7-10 hours; lighting time is 2.5 - 48 hours depending on level of brightness. It can also be used to charge small devices such as cell phones via USB, and can, itself, be charged from a USB source. Lastly, it has a hand crank, so if all else fails, just turn that crank for a bit.

It is quite compact, as you can see, quite lightweight, and has these nifty fold out legs so you can set it up on a table or night stand. There is also a top handle so it can be hung from overhead if needed. Now, this may strike some as silly or overkill, but I will remind you that there is NO electricity there and we will be there in January. One of the little details of life at lower latitudes is that the sun goes down directly over the horizon with very little twilight time. The sun sets right around 6pm and it is dark fast. This is right around the time we take our dinner and eating by light of a small headlamp (tough to use a knife and a fork while holding a flashlight)  is not as charming as one might expect. It also may help me avoid some of those venomous snakes mentioned in the HASP on the path to the latrine at night. I am really stoked to use this baby!

Admit it...you want one.

Current Plans

So, as it stands, we have preliminary approval to return for implementation of  the addition of a pair of 55 gallon drums to the current pair of 600 gallon tanks. This allows the 55 gallon drums to be dosed with pre-measured amounts of chlorine (in the form of liquid bleach) to achieve the correct concentration to disinfect yet not leave an unpleasant taste in the water. (This cannot be done in the 600 gallon tanks as they are continuously being either filled by incoming rainwater or drained for utilization and there is no steady-state volume to dose). The physical scope of this project is smaller than last years but will be coupled with a more intensive community outreach and education component.

The  lineup of the returning team is not yet finalized; Mike is in the process of making those decision but will consist of two mentor engineers and five student engineers. I am one of the mentors; unfortunately Scott has scheduling conflicts (we are hopefully working on a well drilling project in Haiti later in the winter or early spring) and cannot go. For a few days it did not look as though any of the other mentors involved in the project were available and I am too junior to suffice on my own. Fortunately my long time mentor and professor, Chip Kilduff, was able to sign on. I am really looking forward to this! On the student side, Mike is definitely there and there are four students to be chosen. Very exciting!

We have spoken with Ambrosio and placed our order for the lumber necessary for the stands - realize that there is no milled lumber on the island - it is all hand cut by chainsaw by Ambrosio and other men in the community. Imagine working with 2 x 4 s all hand cut, yet amazingly true. We also have our shopping lists ready for the necessary hardware from Maderas Richards on Isla Colon. One of the hard lessons we learned last time was that the nispero wood on the island is so hard and dense that regular nails bend and screws shear their heads off even when pre-drilled; we will bring our own supply of heavy gauge timberlock screws with us. I also want to schedule a little tutorial time with Kyle before the trip to make sure I am good on my use of PVC, in particular, the flanges of the spigots where they seal to the sides of the drums. The fact that we were there once before doing construction is a huge advantage and I hope to avoid many of the small problems that dogged us last year. Which brings me to the topic of footwear.

Last January during the installation it rained. I mean it really, seriously rained. Every day. Which turned the work site to a morass (yes, I used the word morass in a sentence) of mud. And, let me just say here, this was no ordinary mud. It was mud on 'roids. The base soil is a dense clay which, when wetted, produces an extremely thick and sticky paste that will easily suck a conventional sneaker or work shoe off of ones foot. At one point last year Kyle became so frustrated that he elected to work shoeless but paid for it with a laceration on the bottom of his foot.Two schools of thought emerged as to what would work best: 1) conventional big old rubber wellingtons, or 2) perforated slip-ons like Crocs. Both of these have their merits and their drawbacks and I am still inclined to try to find other choices. I will develop this topic further as travel time approaches and I will need to make my decision. It will also be a good place to discuss other good gadgets for such and expedition. Stay tuned.