Centre tightens effluent discharge norms for sugar mills

The government has notified stricter environment standards for sugar industries across the country in order to minimise water pollution. The ministry of environment, forest and climate change had, on 14 January, notified the standards in the Gazette of India.

The new guidelines limit the specific level of waste-water discharge to ''200 litre per tonne of cane crushed'', as against the earlier limit of ''400 litre per tonne cane crushed''.

This, according to the ministry, will ultimately result in less consumption of raw water at operational level. The final treated effluent discharge has been restricted to 100 litre per tonne of cane crushed and waste water from spray pond overflow, or cooling tower blow down has been restricted to 100 litre per tonne of cane crushed.

In order to improve operational efficiency and improve treated effluent recycling practices, only a single outlet point from a unit will be allowed. Further, this single outlet/ discharge point will be brought under the ''24x7 online monitoring'' protocol.

The number of effluent quality parameters to be monitored for ascertaining compliance has now been increased to six – ie, pH, bio-chemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS) and oil and grease (O&G).

Earlier, the notified parameters were only BOD and TSS.

The emission limits for particulate matter from stack has been limited to 150 milligramme per normal cubic metre.

The notified standards also contain a protocol for 'treated effluent irrigation' and 'waste-water conservation and pollution control management', wherein treated effluent loading rates (in cubic meter per hectare per day) have been mentioned for different soil textures.

The waste water conservation and pollution control management mandates that individual units will establish cooling arrangement and polishing tank for recycling excess condensate water to process sections, or utilities, or allied units.

The effluent treatment plant (ETP) will also be stabilised one month prior to the start of crushing season and will continue to operate up to one month after the end of crushing season. The protocol has also made it obligatory for the industry to install flow-meters at all water abstraction points so that fresh water usage can be minimised.

Further, the industrial units have been permitted to store treated effluent in a seepage proof lined pond, having 15 days holding capacity.

The revised standards, if fully implemented, will lead to improved operational performance of sugar industries through implementation of wastewater discharge standards and waste water conservation and pollution control management protocol. It will also help the CPCB and state pollution control boards (SPCBs) / pollution control committees (PCCs) in implementing specific measures to be adopted in sugar industries, with the aim of reducing consumption of fresh water usage, checking operational efficiency and enhancing compliance.

The new standards, which have been recommended by the Central Pollution Control Board (CPCB), after consultations with industries and other stakeholders, as well as seeking comments from general public, are to be implemented from the date of notification.

The Indian Sugar Mills Association (ISMA) welcomed the ministry's move stating that these are urgently needed, but may take time to implement as some mills continue to use old technology.