Saturday, January 15, 2011

Nebbi Wells a Success!

Hello all!

Here's a summary how things turned out with the wells in Paidha, Nebbi District on the border of Congo: (it's a little technical, but perhaps nice change of pace from the normal blog diction)

Well #1 named “God Given” by the local community

Location: Two hills (10 minute walk) away from Sister’s Cathedral, a site chosen by her trusted Brother for good community access.

Diameter: 5”

Total Depth: 33’

Pump set at 31’ (12” above gravel pack)

Feet of water: 12

Notes: We had the well down to 39 feet, but made the mistake of pumping out the well to try to reduce hydrolock that was causing us to lose loads out of the auger. Ended up collapsing the well to 33’, and at the time our 6” casing hadn’t arrived, so we set the pump at 31’. Lesson learned. After two days of pumping, the water has clarified, but is still slightly cloudy from sand particles. The well cannot be pumped dry.

Well #2 (not yet named)

Location: Down the hill from Sister’s Cathedral, located in a cassava field owned by Sister. It’s about 150 feet away, uphill from the open water stream.

Diameter: 6” to 45’, then 5” to 53’

Total Depth: 53’

Pump set at 48’

Feet of water: 25

Notes: Drilled with 6” to 45’, tried to get 6” casing down, but had to widen hole with bailing wire tied around auger. Finally drove 6” casing down to 45 feet (with an upside down table, 1000lbs of gravel pack, and Bitek and I jumping on top- photo coming…) Set 4” casing down to 52’, then put 6” large gravel, followed by 2’3” gravel pack, bringing the level to the 50’3” depth mark. Set the pump a bit high because we had 4” of sediment settle in the well overnight, and wanted to play it safe (we also have 25 feet of water in good aquifer, and don’t anticipate being able to pump it dry. After pumping for a few hours, the clay cleared, and only the cloudiness from the sand particles remains. Due to time constraints, we weren’t able to measure recharge rate. This is the location on which Sister plans to build a medical clinic, so we’re hoping that this well may clarify with time, and perhaps even support a solar pump sometime in the future.

Local youngsters helping out with the pipes

Brick and concrete foundation

We sure learned a ton about the fine art of working delicately in unstable layers, and about the importance (and challenge!) of using 6” casing. We’ve gone with a taller tripod, and 20-24 feet tubing sections for quicker transitions (and also due to a dearth of viable square to round end pieces!)

After pouring bleach, and leaving the first well for two days, the locals have already begun using the well. It has not cleared entirely of sand yet, but is already so much more pure than the muddy stream that it’s the best option, and the community is happy with it. We expect the water to become completely clear within a week or so, but regardless, the water should be free of the typhoid and other diseases currently wreaking havoc on the community members’ health.

Still thirsty?... a couple of videos:

Pumping Water...

Down Through the Layers...

A well deserved rest.

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