If he meant Thrugg Lake, New Jersey, then you can walk on that. It's a man-made job set atop an old landfill formerly used by a nickel-plating company, a nitrates factory and a lead foundry. The variety, amount and quality of pollutants leeched from the ground give the water a slightly tougher consistency than very old jello.
Of course, you shouldn't smoke a joint on your hike. Open flame sources tend to make the water explode. But if the breeze isn't sufficient to dilute the rather heady vapors, you can rent an oxygen mask from Fred, the Almost-Recovered Wino. He's near the disused bait shop and can also show you how to mount and use this important and complex bit of equipment safely. On his day.
You can also walk the lake at night without fear of tripping over ripples. The water (as also the surrounding vegetation) is autoluminous.