India, Jan. 29 -- The Aam Aadmi Party (AAP) has alleged that the Bharatiya Janata Party (BJP)-led Haryana government is poisoning the Yamuna's waters, triggering a fresh flashpoint in the acrid Delhi elections campaign. But the claim has also turned the spotlight on a real problem - severely excessive ammonia levels in the Yamuna, especially in its stretch through the National Capital Region (NCR).

Data and records from state agencies suggest that though Haryana does release water laden with ammonia into Delhi to an extent, this is largely due to systemic chinks in the region's drainage networks and not a deliberate ploy. Further, while the Yamuna is polluted when it enters the Capital from the north, it leaves the city in significantly ...