The CPCB identified sludge accumulation and nitrogen-rich wastewater as key factors behind the. Accumulated sludge in the Yamuna bed at Wazirabad may be contributing to ammonia spikes that have caused recent disruptions in Delhi’s water supply, preliminary findings of a Central Pollution. NEW DELHI: A prolonged disruption in water supply is unfolding across the national capital, leaving thousands of households struggling without regular access and fuelling concerns that the.