Q.Read the given passage carefully and answer the questions that follow : Water Pollution Industries produce several undesirable products including industrial wastes, polluted waste water, poisonous gases, chemical residuals, numerous heavy metals, dust, smoke, etc. Most of the industrial wastes are disposed off in running water or lakes. Consequently, poisonous elements reach the reservoirs, rivers and other water bodies, which destroy the bio-system of these waters. Major water polluting industries are leather, pulp and paper, textiles and chemicals. (19.1) Explain how industries are the major contributor of water pollution in India. (19.2) Suggest the way for minimising water pollution. (19.3) Mention two rivers of India which are highly polluted.

Urban Waste Management Issues: Industrial Water Pollution

(19.1) How industries are the major contributor of water pollution in India

Industries generate a wide array of undesirable by-products during manufacturing processes. These include industrial wastes, polluted wastewater, chemical residuals, numerous heavy metals, and other toxic substances. The primary problem arises because most industrial units dispose of these wastes directly into running water bodies or lakes without adequate treatment.

When poisonous elements and chemical residues enter reservoirs, rivers, and other water bodies, they destroy the delicate bio-systems that sustain aquatic life. The contamination disrupts ecological balance, kills fish and other organisms, and renders water unsafe for human consumption or agricultural use.

Among the industrial sectors, leather, pulp and paper, textiles, and chemicals stand out as the major water polluting industries. Each of these sectors uses large volumes of water in production and discharges effluents laden with toxic chemicals, dyes, acids, and heavy metals.

(19.2) Ways for minimising water pollution

Several measures can reduce industrial water pollution:

• Treatment of effluents: Industries must install effluent treatment plants to remove toxic substances before discharge.
• Recycling and reuse: Water used in industrial processes should be recycled wherever possible to reduce both consumption and waste.
• Adoption of cleaner technologies: Switching to production methods that generate less waste and use fewer hazardous chemicals. …

How Industries Drive Water Pollution in India

India's rapid industrialisation has come at a steep environmental cost, and nowhere is this more visible than in the contamination of rivers, lakes and groundwater. The passage identifies a grim inventory of industrial by-products—chemical residues, heavy metals like mercury and lead, dyes, acids, and organic waste—that flow unchecked into water systems. What makes industrial pollution particularly destructive is its chemical persistence: unlike organic sewage, many industrial pollutants do not break down naturally and accumulate in sediments and living organisms.

The leather industry, concentrated in states like Tamil Nadu and Uttar Pradesh, uses chromium salts in tanning; these chromium compounds are highly toxic and carcinogenic. Pulp and paper mills discharge lignin, chlorinated compounds and suspended solids that deplete dissolved oxygen, suffocating fish and other aquatic life. Textile units release azo dyes and bleaching agents, some of which are mutagenic. Chemical plants add a cocktail of solvents, acids and synthetic compounds. When all these effluents enter a river, they do not simply dilute—they interact, often becoming more toxic, and they travel downstream, affecting millions who depend on that water for drinking, irrigation and fishing.

A river's capacity to self-purify—its ability to break down organic matter through microbial action—is overwhelmed when industrial loads are added to urban sewage. The result is eutrophication (excessive nutrient enrichment leading to algal blooms), oxygen depletion, and the collapse of fish populations. Downstream communities face waterborne diseases, and farmers irrigating with polluted water introduce toxins into the food chain.

Minimising Water Pollution: Practical Pathways

Tackling industrial water pollution requires a combination of regulatory muscle, technological upgrades and economic incentives.

Effluent Treatment and Zero Liquid Discharge

Every industrial unit must install and operate effluent treatment plants (ETPs) that remove or neutralise pollutants before discharge. The most ambitious approach is zero liquid discharge (ZLD), where all wastewater is treated and recycled within the factory, leaving no effluent to enter natural water bodies. This is already mandated for industries in water-scarce regions and along critically polluted river stretches.

Cleaner Production Technologies

Shifting to less toxic inputs—vegetable tanning agents instead of chromium, water-based dyes, closed-loop cooling systems—reduces pollution at source. Process modifications that lower water consumption and chemical use not only cut effluent volume but often improve cost efficiency.

Stricter Enforcement and Monitoring

Pollution control boards must conduct surprise inspections, levy heavy fines for violations, and in extreme cases, shut down repeat offenders. Real-time online monitoring of effluent quality, already piloted in some states, removes the scope for tampering and ensures accountability.

Economic Instruments

A polluter-pays principle—charging industries for the volume and toxicity of their discharge—creates a financial incentive to clean up. Conversely, subsidies or tax breaks for adopting green technologies can accelerate the transition.

Public Awareness and Community Vigilance

Local communities living along polluted rivers are the first to suffer. Empowering them with information and legal tools to report violations turns citizens into watchdogs, complementing official enforcement. …