It follows concerns about the Gaywood River, one of only about 200 chalk streams in the world.
A court is shown police video footage of Mr Hill's arrest in the school car park.
Gregory Clarke is facing charges of harassment against a teacher and resisting arrest.
Work on some 250 homes in Hunstanton and Gaywood has been affected and council costs have risen.
Demolishing it to build a care home would destroy a town's heritage, a conservation group warns.
Mattheus Viera, 11, "would have survived" if started on a sepsis pathway sooner, coroner says.
The Environment Agency believes it has identified potential sources of the pollution.
Gregory Hill, who changed school name to Harry Kane Junior during World Cup, appears in court.
Inspectors find a junior school "failed to spot and act upon serious and significant concerns".
