Yamuna sludge, drain water behind ammonia spikes: CPCB

CPCB has found that sludge accumulation in Wazirabad pondage and nitrogen-rich drain water are causing recurring ammonia spikes in the Yamuna, disrupting Delhi's water supply. The board warned that one-time dredging won't fix the problem and that nitrogen levels in drains must first be brought within acceptable limits for lasting improvement.