LAVALETTE, N.J. (CBSNewYork/AP) — New Jersey lawmakers are concerned over potential health risks posed by a giant brown silt plume that was released into Barnegat Bay last week.

The plume was spotted Wednesday by a drone from Seaside Park’s public works department, reported.

READ MORE: Gov. Cuomo Agrees To Attorney General James' Demand For Legal Referral To Investigate Sexual Harassment Allegations

“Some folks did notice that they were swimming in what they thought was gunk and they didn’t really know what it was,” Britta Wenzel, executive director of the group Save Barnegat Bay, told 1010 WINS.

It spanned more than six blocks just south of the Mathis-Tunney Bridge in Seaside Heights.

“Three blocks in one direction is the children’s swimming beach and three blocks in the other direction is the Seaside Park Yacht Club so it’s a very heavily used recreational spot with folks on paddleboards, swimming, crabbing, fishing, doing all the things that people do in the Barnegat Bay in the summertime,” Wenzel said.

READ MORE: Jersey City Police Investigating Fatal Shooting At Shopping Center

State officials said the discharge does not pose a public health risk.

But Senate and Assembly environment committees want an explanation how the plume occurred and whether a flood abatement project is to blame.

The plume came from one of nine pumping stations along Route 35 from Bay Head to Seaside Park. The pumps are part of a $200 million infrastructure upgrade stemming from the damage from Superstorm Sandy in 2012.

“We believe the plume was silt coming from these pumping stations and then the force of the water hit the bottom floor of the bay and turned up even more sediments,” Wenzel said.

MORE NEWS: COVID Vaccine: Johnson & Johnson Shots Expected This Week, Fauci Urges Americans Not To Be Discouraged By Efficacy

(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)