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The effluents from the systems of Block D were discharged into
a canal and the effluents from the other blocks
were discharged into two different ponds. The canal had flowing
water and looked in relatively better condition
than the other water bodies. The condition of the ponds, particularly the pond that received wastewater from the
system of Block C was very poor; many open latrines were on the banks, and heavy eutrophication was noticed.
Wastewater from dye, ceramic, glass and other industries were being discharged into both the canal and the ponds.
It was reported that fish were dying in the ponds and canal, and people expressed concern about it, but it is not
clear as to exactly why the fish were dying.
In addition to conducting a wastewater
analysis of the biogas based sewerage system, another analysis of the
raw wastewater in pit latrines that were not connected to biogas based sewerage systems was also conducted.
In total, one pit latrine from every block except Block A was tested. As shown in Table 6.4, the BOD and CODCr
ranged from 1200 mg/l to 4000 mg/l, and 2270 mg/l to 8670 mg/l, respectively. It clearly indicated that the organic
concentration of the pit contents varied significantly, partially due to the state of decomposition.
Table 6.4:
Results of the chemical
analysis of the raw wastewater from pit latrines that are not connected to
biogas
based sewerage
system.
In the case of Japan, the average generation of the human waste alone (without flushing or washing water) is
0.0014
m 3 /person/day, and the average quality is shown in Table 6.5 (Japan Waste Management Association, 1978).
It is assumed that the BOD concentration of the
wastewater in the pit latrines of Bauniabad is approximately 10
times more diluted than the human waste in Japan, and this is evident when comparing Tables 6.4 and 6.5. This
may
be due to the use of a large amount
of water for flushing
and washing
after
defecation.
Assuming
that the
amount
of human waste alone (without
flushing or washing
water) per
person
per day in Bauniabad
is
almost the
same as Japan, it is estimated that about 0.63 m 3 /day (=0.0014 m 3 /person/day x 4.5 person/family x 100 family) of
human
waste is flowing
into
one of the biogas chambers in Bauniabad, which have an approximate volume of 11
m 3
. From
this amount
of waste
going into each of the biogas chambers,
it can be
assumed
that the retention time
can
be
calculated to be
approximately
17 days (=11 m 3 /0.63 m 3 /day), which is clearly insufficient for proper anaerobic
digestion.
Furthermore,
the large amount of the flushing and washing water that is going into each of the biogas
chambers also contributes to making the retention time much shorter than 17 days.
Table 6.5: The quality of human waste in Japan.
6.5 Community Participation
The
community participated
in the sanitation
component
of
the project
through the
Environmental
Health
Committee
and through respective
biogas
committees.
The
operation
and maintenance
of the lesser
complicated
elements
of the system, as
well as its cost
sharing,
were done
by the users
through
biogas committees;
one Biogas
Committee was formed for every system during 1997-2000. Through major coordination during the planning and
installation of the options, these Committees were able to maintain close links with the Environmental Health
Committee. However, recently these types of committees are not being formed, and previously formed committees
are not functioning, leading concerned citizens to directly conduct negotiations concerning the operation and
maintenance
of
the system with
Plan International.
Due to this reason, the discussions on a possible solution of
the recent problems concerning the systems are facing various kinds of delays and coordination gaps. It may be
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