Page 319 - Industrial Wastewater Treatment, Recycling and Reuse

Urban Wastewater Treatment 293

Table 7.4 Hydrologic water balance of India (http://www.nih.ernet.in/rbis/india_
information/Water%C2%A0Budget.htm)
Inflow Outflow
Term Value Term Value
P 400 E T 278
20 126
I s Q s
4 20
I g Q g
Total 424 Total 424
10
3
All components in (10 )m per year.
Source: Hydrology and Water Resources System for India.
groundwater aquifers. Septic tanks constitute one of the most common forms
of urban sanitation facilities in India. The major parts of urban India have not
been connected to a municipal sewer system, which makes people dependent
on the conventional individual septic tank. Access to improved sanitation in
urban India has increased, but the management of on-site sanitation systems,
such as septic tanks, remains a neglected component of urban sanitation and
wastewater management. Sewage generated lacking treatment facilities con-
tributes to 80% of the pollution of the national surface waters (CSE, 2011,
2012). Based on water pollution, five different classes of water quality have
been identified. Data show that, from an Indian river 45,000 km in length,
6000 km had a BOD 3.27 above 3 mg/L, making the water unfit for drinking.
Matters relating to sewage treatment as well as the drinking and industrial
water supply are dealt with at the state level while the municipal authorities
of cities are responsible for providing these services. Currently, only the net-
worked sewage systems are targeted for treatment, while the vast nonpoint
source discharges go undetected and untreated. Therefore, the pollution loads
in rivers are highly variable, depending on the season, modulated by rainfall,
sewage, and solid waste management practices in towns and cities, and types of
industry in the proximity. While the regulatory mechanisms have been out-
lined, uncontrolled industrial discharges contribute to heavy environmental
pollution and potential health hazards (Rawat et al., 2009). Hence the order
of the day would be to reassess and redesign the whole urban wastewater treat-
ment system with a perspective to recycling and reuse for industrial and other
domestic applications.

7.2.7 Urban Sewage Quality and Quantity
3
The total water requirement for the industries was around 11 km /year for
the base year 1996–1997. It was observed that the pulp and paper, integrated