The Army will demonstrate on Friday underwater technology that will be used over the following three weeks to gauge whether old, discarded munitions can be removed from relatively shallow waters off the Waianae Coast.

The Army, National Oceanic and Atmospheric Administration and ARA Inc., will brief the news media at Pearl Harbor about the start of the upcoming $2.5 million project at what’s known as “Ordnance Reef.”

During a three-week period, the Army will assess the feasibility of adapting remotely operated technology used by the oil exploration industry for the recovery of military munitions on the ocean floor.

At the same time, the Army will be assessing the feasibility of cutting munitions from coral concretions and then rendering the munitions harmless by cutting them open on a barge and using heat to break down chemical compounds.

The demonstration site is located more than one mile off-shore in waters between approximately 30 and 120 feet in depth. The Ordnance Reef site, known as HI-06, is two miles south of Waianae’s Pokai Bay and covers five square miles.

The Ordnance Reef project might cost up to $6 million and includes studying the long-term effects on marine life and regenerating coral reef in the area.

The Army expects to start with the demonstration project to see if munitions can be safely collected using remotely operated vehicles. Officials said the benefit of removing ordnance from coral would have to be weighed against the harm in cutting it out.

Waianae Coast residents demanded in 2007 that the military clean up thousands of tons of explosive and chemical munitions dumped in relatively shallow and deep waters off the Waianae Coast after World War II.

The Army said studies of the Ordnance Reef site concluded there was no “imminent or substantial threat” to human health or to the environment, from either the explosive hazards or a potential release of explosive compounds.

The assessment of the explosive risks found that the greatest risk is from deliberately disturbing the munitions.

An environmental assessment for the demonstration project is available at: http://www.ordnancereefhawaii.org/