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] 90
A B
et ter
W
or ld
should be defined taking into account the varying rainfall
and soil types of the agro-ecoregion, with budgetary allo-
cations for different interventions as needed rather than
imposing a system of fixed allocations across the country.
There is also need to consider climatic variability including
frequency of extreme events while designing a water harvest-
ing protocol. Earlier studies have demonstrated the benefits of
low-cost water harvesting structures throughout the topose-
quence, which benefited a greater number of farmers than
the construction of masonry check dams would have done.
19
The risks of raw wastewater irrigation
A global municipal wastewater discharge of about 330
million m
3
per year can potentially irrigate 40 million
hectares
20
, or 15% of all irrigated lands. Globally, about 5 to
20 million hectares of land is being irrigated with raw waste-
water
21
which is about 2 to 7% of the total irrigated area.
However, inappropriate reuse of untreated wastewater is unsafe
for farmers’ as well as consumers’ health.
22
Farmers, oblivious
to the potential harm of raw wastewater on human and soil
health, utilize it for irrigation during the dry summer months.
Location
Units Capacity (m
3
day-1)
Collaboration partner/s
ICRISAT, Telangana
1
28
ICRISAT
SAB Miller, Telangana
1
50
ICRISAT, SAB Miller
Kothapally, Telangana
2
35
ICRISAT
Bhanur, Telangana
1
56
ICRISAT, NGO, Asian Paints
Nagolpally, Telangana
1
30
ICRISAT, NGO, Govt. of India
Sangareddy, Telangana
1
10
ICRISAT, NGO
Mahboobnagar, Telangana
1
10
ICRISAT, RECL, NGO
Jhanshi, Uttar Pradesh
1
2
ICRISAT, CAFRI, NGO, Govt. of India
Kurnool, Andhra Pradesh
1
51
ICRISAT, NGO, Power Grid Corp
Kolar, Karnataka
1
10
ICRISAT, NGO, Coca-cola
Chikkaballapur, Karnataka
3
80
ICRISAT, Govt. of Karnataka
Chikkmangalur, Karnataka
6
180
ICRISAT, Govt. of Karnataka
Bijapur, Karnataka
2
90
ICRISAT, GoK, Power Grid Corp
Bellary, Karnataka
2
64
ICRISAT, NGO, JSW Foundation
Tumkur, Karnataka
8
160
ICRISAT, Govt. of Karnataka
SI No.
Parameter
Unit
Inlet
Outlet
Removal Efficiency (%)
1
Calcium
mg/L
95.69
88.45
7.6
2
Chemical oxygen demand
mg/L
96
21.1
78
3
Chloride
mg/L
174
166
4.6
4
Electrical conductivity
ms/cm
2.39
2.12
—
5
Potassium
mg/L
58.89
58.72
0.3
6
Magnesium
mg/L
35.23
32.82
6.8
7
Sodium
mg/L
239
197
17.6
8
Inorganic nitrogen
mg/L
18
3.96
85
9
pH at 25°C
—
7.98
8.78
—
10
Phosphate
mg/L
1.88
1.17
37.8
11
Sulphate
mg/L
2.83
0.48
83
12
Total dissolved solids
mg/L
2019.50
1432
29.1
13
Total alkalinity
(mg/L as CaCO3)
406
315
22
14
Total hardness
(mg/L as CaCO3)
410
340
17
15
Sodium absorption ratio
—
5.3
4.5
—
Table 1: Details of the constructed wetlands implemented at field scale
CAFRI: Central Agroforestry Research Institute; RECL: Rural Electrification Corporation Limited
Table 2: Wastewater treatment efficiency of the constructed wetland at SAB Miller, Sangareddy
Source: ICRISAT