Planning for Water Storage: Splash follows a two step process to determine the required minimum amount of water storage at our sites.  The first step is to calculate the minimum storage volume based on the population of the site, while the second step is to make sure that every piece of water and sanitation infrastructure at the site is connected to a sufficient volume of water.

The first step: For non-boarding/non-residential schools, Splash has determined that sites in Addis Ababa need a minimum of 3 days’ of water storage volume, whereas sites in Kathmandu need a minimum of 2 days’ storage, and sites in Kolkata need a minimum of 1 day’s storage.  A single day’s water storage requirement is defined as 9 liters per person per day for a non-boarding/non-residential school.  This leads to the calculation for Addis Ababa of 3 days’ storage multiplied by 9 liters/person multiplied by the total number of people at a site in one day.  Finally, the number you get through this multiplication is rounded up to the nearest 1,000 liters.  For example, a school site in Addis Ababa with 300 morning students, 500 afternoon students, 100 night students, and 40 total staff gives you a total population of 940.  The Addis Ababa WASH Infrastructure team would then multiply 940 persons by 9 L/person/day and then multiply by 3 days to get 25,380 liters.  The 25,380 liters is then rounded up to the next 1,000 L to get a final required minimum storage volume of 26,000 liters.  The above calculation would be done very similarly for school sites in Kolkata and Kathmandu, but the number of days of storage required in the calculation would be different.  

Many sites have existing storage tanks.  These existing storage tanks can contribute to meeting the required minimum storage volume only if they are functional or can be made functional by a reasonably minor repair such as a valve replacement, and if they are (or can be) connected by a pipe to taps, toilets, or other fixtures (barrels for pour-flushing do not count).  No existing tanks that are rusting, leaking, have an open-top, or have other holes in them can be used to contribute to meeting the required minimum storage volume.  Let’s assume the aforementioned Addis Ababa school site that needed 26,000 L already had two 5,000 L fiberglass tanks that were functional as well as an older 10,000 L metal tank with an open top, and five 200 L plastic barrels used for pour-flushing toilets.  We can count the two 5,000 L tanks towards meeting the required 26,000 L, but the metal tank should not be counted since it has an open top (big hole), and the plastic barrels should not be counted since they are not and cannot be connected to anything.  This would mean that Splash would need to install 16,000 liters of additional storage tanks at this site.  

For boarding (or residential) school sites and orphanages, the daily storage volume would increase to a much higher 20 L per resident plus 9 L per non-resident.  For hospitals, the daily storage volume is 50 L per bed, plus 10 L per daily outpatient, plus 10 L per daily staff.  

In order to define all of the daily storage volume minimums, Splash based these on the UNHCR’s Emergency Handbook’s Longer-Term Standards and included guidance from the Ethiopian and Indian national WASH guidelines.  The minimum standard of 9 L/person/day can be broken down in the following way:

• Drinking - 1 L
• Food prep - 0.5 L
• Handwashing - 1.5 L
• Cleaning toilet areas - 0.5 L
• Cleaning other rooms - 0.1 L
• Flushing toilets - 4 L
• Personal cleaning (includes MHM) - 1 L

Adding up all of the above yields 8.6 L/person/day which we then round up to 9 L/person/day.

As noted, the above total also includes all necessary water for menstrual hygiene management related personal cleaning.  This is based on the following assumptions and calculations:

• 5 days of flow per 30 day cycle (1/6)
• 5 school days per 7 days (5/7)
• Avg of 10 menstrual product changes during 5 days of flow (2/day of flow)
• 1 L of water required for cleaning during menstrual product change
• = (1/6)x(5/7)x2x1 = 0.24 L/school day/female student regardless of toilet type, rounded up to 0.25 L  

So, each female user above the age of 10 will need an additional 0.25 L per day for MHM.  This 0.25 L per day is accounted for in the rounding up from 8.6 L/person/day to 9 L/person/day.

 

The one exception to the 9 L/person/day standard is when a site must have pull-flush toilets (these are also known as cistern flush toilets).  Since these toilets can use between 6 and 10 L for every flush, we must increase the required minimum storage volume per person from 9 L to 17 L/person/day where cistern flush toilets are installed. Because of this very large increase in required storage volume, Splash should never install pull-flush / cistern flush toilets, and instead Splash should only be installing pour-flush toilets paired with a tap and bucket inside each stall for flushing.  Please see the Sanitation standards for more details.

 

The second step: The above minimum water storage amount is only the first step to determine how much storage volume Splash needs to install.  The second step is to consider where at the site is storage needed.   The following areas are the first places to make sure that there is sufficient water storage: Splash drinking stations, Splash handwashing stations, all functional sanitation facilities (for toilets and urinals), food preparation areas, and medical rooms.  Even if a site meets or exceeds the minimum storage volume based on the site population that was calculated in the first step, but the site does not have enough water storage volume connected to each of the pieces of infrastructure listed above, then Splash must provide more storage tanks to meet that demand.  The minimum volume is to provide at least 100 L per drinking tap, 150 L per handwashing tap, 75 L per dry/drop toilet stall, 300 L per pour-flush toilet stall, 25 L per urinal space, 300 L per shower stall, and 150 L per kitchen, janitor's, or medical room tap (all volumes are per day).  For  toilet stalls (both dry/drop and pour-flush) serving female users over the age of 10, an extra 20 L/day per toilet stall should be added.  For Addis Ababa, which needs at least 3 days of supply, we would multiply all of these numbers by 3.  For Kathmandu, which needs at least 2 days of supply, we would multiply the above numbers by 2.  Finally, for Kolkata, we would not multiply these numbers by anything since Kolkata only needs 1 day of supply as a reserve.

Because of this second step, we may often need to install more water storage volume at a site than the result that we got from the first step's population calculation.  This is okay, because it is critically important that every piece of infrastructure at a site is connected to enough water storage volume to ensure that the users at our sites have access to water.

The required volume of storage tanks that Splash must install at a site is always and only based on the above two steps.  Splash can never be finished at a site if the site does not meet the required minimum volume of water storage.  If there are physical space constraints that will not allow Splash to meet the required minimum storage volume at a site, then the local WASH Infrastructure Lead must contact the global WASH Infrastructure Manager about the situation.

Number of storage tanks: There must be enough water storage volume to allow for normal infrastructure functionality during the routine cleaning and maintenance of the largest water storage tank on the site.  At least 25% of the site's water storage volume requirement must be located outside of the single largest water storage tank on the site.  This 25% can be distributed across several smaller water storage tanks or centralized in single large secondary tank.

If a campus has physically separated grades or groups of students (such as a separate kindergarten area), then the above ratio and infrastructure calculations need to be applied to each physically separate group of students and staff on that campus separately.  

As with all Splash infrastructure implementations, all of the above minimum standard and ratio calculations are the lowest amount of storage that we must install at each site.  There may be unique circumstances and sites where the best solution is to install more water storage than the minimum calculations demand.  This is okay, and it is left up to the judgment of the local WASH Infrastructure Lead, with consultation from the Global WASH Infrastructure Lead, to make the judgment on how much additional water storage is needed to address each unique situation.

 

Installation of Storage: When installing water storage tanks at a site, we must always make sure that all of the Splash stations and functional sanitation infrastructure is connected to at least the minimum water storage volume set by the second step above.  Depending on the size and layout of a site, the water storage tanks can be distributed across a site, or they can be concentrated in one area.  This is left to the judgment of the local WASH Infrastructure Lead with consultation from the site leadership as long as all infrastructure is connected to sufficient water storage.  

If any existing water storage tanks need minor repairs, then these repairs should be made at the same time as the installation of new water storage tanks.

Water storage tank installation can happen during any phase of work: sanitation rehab, sanitation new construction, and/or water implementation.  It is the local water infrastructure manager's responsibility to make sure that each site in their city meets all of the above minimum volumes for water storage before the infrastructure work at a site can be marked as complete.

 

Demolition or Removal of Existing Irreparable, Leaking, or Dangerous Water Storage Tanks: If there are existing water storage tanks that are leaking, dangerous, or otherwise completely non-functional, the local Infrastructure Team must determine if these storage tanks can or should be repaired.  If any existing tanks are deemed irreparable, then the local Infrastructure Team must get signed and dated permission from the site management for the demolition or removal of those tanks.  It is Splash's (and the contractors that we hire) responsibility to have all debris, junk, and other waste from all demolition, rehab, and construction work removed from the school grounds and correctly disposed.