HOPATCONG — More water tests and a flyover look at Lake Hopatcong led the state Department of Environmental Protection to keep an indefinite ban on most water activity because of a harmful algal bloom.

The DEP posted warnings about having contact with the water in New Jersey's largest lake after more than 30 reports of harmful algal bloom at the North Jersey lake since June 17, including incidents of mild skin rashes.

Exposure to HAB also may cause allergy-like reactions, flu-like symptoms, gastroenteritis, respiratory irritation and eye irritation.

Some people and businesses around the lake are not heeding the warnings.

David Gedicke of Lake's End Marina told the Morristown Daily Record that people are still swimming and enjoying the lake without any ill effects. Gedicke said as long one doesn't go swimming it's still OK for boating, sunbathing and fishing.

What did the DEP's latest testing find?

Cell counts for the cyanobacteria that is causing the bloom remain above the New Jersey Health Advisory Guidance levels. The levels are the highest below the surface.

What does the bloom look like from the air?

The DEP said that while the interior portions of the lake appeared to be clearer than last week, water sampling showed continued elevated levels of cyanobacteria. This means that the water may appear free of a surface bloom but dangerous bacteria can still be present below the surface.

What is banned?

Swimming and watersports such jet-skiing, water-skiing, paddle-boarding, canoeing or kayaking. The DEP advises not to drink the water or eat fish caught in the lake.

Is there anything I can do in Lake Hopatcong?

The DEP said that "passive boating that does not involve bodily contact with lake water" is allowed.  The other facilities at Hopatcong State Park are still open.

How long will the ban last?

The testing and aerial surveillance of the lake will continue and until the cell counts for cyanobacteria is at or below acceptable levels. That could take weeks or all summer.

The DEP has a similar ban at the Spruce Run Recreation Area in Clinton because of HAB.

Contact reporter Dan Alexander at Dan.Alexander@townsquaremedia.com or via Twitter @DanAlexanderNJ