Aceh salinated wells

Wells in tsunami hit areas in Aceh have been polluted with salt water. We are planning to clean them and would like to receive confirmation if the proposed method of cleaning is appropriate.

Background information

People in the tsunami affected villages in Banda Aceh are fed up with living in camps and want to go home. Home is often no more than the foundations of what is left of their house, a pile of wood and a contaminated well.

The aim is to set up two well-pump teams to empty 50 wells in 10 days in an area of 80 square km. The water from these wells will be used for washing clothes and for sanitation. Drinking water will arrive in water tankers. On the whole, local people know about water and hygiene but because there is a lack of facilities, diarrhoea and infectious diseases are constant threats.

The teams, which consist of local staff, will go to the villages/places were people are busy rebuilding. They will empty wells, build emergency latrines, install temporary drinking water tanks, and drive in drinking water and materials to construct public toilets in the houses, schools and health centres.

Approach to follow

The following approach is proposed:

•  GPS positioning of the wells (distance to the sea, rivers etc.) hoping that this method will separate the usable wells from the unusable ones (too much salt). This will help set priorities by distinguishing those tsunami affected villages which can be saved and which ones cannot (because economic resources and water sources have been destroyed and dunes washed away).
•  Centrally located wells are a priority. A minimum of one or two clean wells per village should be feasible. Boreholes are not yet being considered.
•  Each team requires a pick-up truck with a motor pump, two men and a self-built PVC sprayer / fire hose.
•  First they pump out the well, take a sample of the water, store it in a bottle and label it. It takes one to two hours to get rid of most of the salty water.
•  At the same time one person goes down the well to dig out the mud and to remove the ferrous deposit on the shaft of the well.
•  When the water starts to rise again in the well, this relatively clean water will be sprayed back onto the well walls under great force from the home-made fire hose.
•  This water will be pumped out again hoping that the amount of salt has decreased. A second bottle will be filled with water from the well.
•  It will be allowed to refill again, this time without any intervention.
•  Salinity tests and monitoring will be done.
•  After a week a third sample will be taken from the well.

Planning

This process will take 14 days. The aim is to install in each location a drinking water tank of 3000 litres, topped up by a daily visit from a water truck, four latrines and one clean well.

Rebuilding central facilities will take longer and will be tackled in the next phase of the aid programme. More relief organisations are coming into the area, but they need at least two weeks to assess the situation before giving effective support. In general, too many of the relief organisations have remained in Banda Aceh and it is only now that they are realising that there are many other areas destroyed by the tsunami where action needs to be taken. At the moment Médecins sans Frontières is the only organisation working on water and sanitation issues.

Confirmation of approach

We want to reconfirm and approve from IRC’s point of view the actions you have already been taking. Emptying and cleaning the wells seems to be the only solution. We have been checking some literature (a.o. Salinity and shallow wells [1]), but there does not seem to be another solution.

Centers for Disease Control and Prevention (CDC) is saying:
 "After wells have been properly cleaned out and they begin to refill with water from the aquifer, much of the increase in salinity (saltiness) should subside. Shallow wells may be more affected than deeper wells because of the higher loading of saltwater in the upper layer of soil. Although recovery of shallow wells may be slower than that of deeper wells, the salinity of shallow wells should lessen over time."

We hope your experience with de-salination of the wells is more hopefull and positive. To be sure we are adding the entire CDC article [2], because it contains information on how to disinfect the well after de-salination.

See also two related articles mentioned below.

Notes

[1] Woodhouse, M. (1995). Salinity and shallow wells : a view from the field. In: Nash, H. ; McCall, G.J.H. ; Groundwater Quality in Developing Countries. Groundwater quality. (AGID special publication series. The geosciences in international development; no. 17). London, UK : Chapman and Hall. P. 105-108: 1 fig., 3 tab. [Not available online]

[2] Tsunamis: water quality. Part of the CDC Emergency Preparedness and Response web page, providing information on disinfecting wells. Centers for Disease Control and Prevention,

Related articles

•  Asia: tsunami has contaminated groundwater says UNEP study, Source Weekly, 10 Mar 2005;
•  Jetting: rapid drinking water supply for tsunami victims, Source Weekly, 24 Feb 2005;
•  Water well disinfection (2005), an emergency well disinfection guide for people who have no expertise in wells and scarce equipment. By the National Ground Water Association.

Practical tip from the field

See user comment on 'Cleaning of wells' below.

Latest Update (3 Oct 2011)

Another user comment on 'post tsunami well cleaning', also below, warned us that it is important to understand the geological environment in which the wells are situated. More information on new cleaning methods and geological environments can be found in the following notes:

• Cleaning and disinfecting wells in emergencies - technical note No. 1 on drinking water, sanitation and hygiene in emergencies by WHO and WEDC, downloadable.
• Cleaning wells after seawater flooding - technical note No. 15 on drinking water, sanitation and hygiene in emergencies by WHO and WEDC, downloadable.
• Deep impact: why post-tsunami wells need a measured approach, article by Lucy Lytton from 2008. This article is available for a charge from the journal ICE

-----------------------------

Date: Feb 2004 (updated 3 October 2011)

This response has been provided by the WELL Resource Centre Network with funding from the UK Department for International Development (DFID).