The director of the Office of Public Health Engineering, Albert Montague, 67, runs a six-person staff within the Department of Health and Mental Hygiene charged with assessing the water quality of 19 of the city’s beaches. The Bronx native sat down in June to talk to The New York Sun’s Hana Alberts about how he monitors the city’s water, how the agency decides whether a beach should be closed to the public, and how the quality of New York’s water has improved in recent years.

Q. What is the role of your agency?

A. We have the responsibility of overseeing the water quality of the beaches of the city of New York, as well as the pools, and that entails having to go literally out there every week and monitor the water quality of those beaches that are under our purview.

The sampling starts a month before Memorial Day. There’s a lot of work to be done in a short period of time.

What are the standard levels of bacteria and how do you measure deviations?

We’re establishing a baseline of what the water quality is. If you had one value and just looked at that one value, and used that as the mechanism of managing water quality, you really are presuming something based on one data point, and it may not be realistic of what’s happening. What if a bird came by and did its thing and you picked up that sample and used it to reflect the water quality? We’re taking several samples at one beach to make sure.

What are the circumstances under which a beach should be closed because of water quality issues?

Overall, before we’re going to close a beach, we want to make sure that it is the appropriate measure to take, we want to see repetitive exceedances to make sure that something has changed, that people swimming there would be at higher risk.

If we were to see an exceedance today, okay, we come back tomorrow, then we say, we have to make bloody sure. We’ll do two or three or four samples to get results – you see three, it’s no good, you’re going to go into advisory mode, and then investigate it further. Then we start talking to other entities to see what is awry.

It’s not based on one sample and we walk away. The public must be served.

For last year, there were no closures. We had no elevated levels that exceeded the levels [appropriate] for the public beaches.

I’ve heard that the runoff from summer storms into the rivers changes the quality of the water. How and why does that happen, and how does it affect your job and the openings or closings of city beaches?

If you have a car, and you drive it on a road, and you put on your brakes, or you have a cat that goes and does its thing on the street, that is all part of the contamination process of storm-water runoff. We have models that can predict, based on a rainfall event, whether a beach’s water quality could be compromised. Those models give us the means by which we can institute what is called a wet weather advisory. They are really prophylactic.

In comparison to other bodies of water, are the ones in New York City more or less clean? Speaking from your 40 years of experience in the field, is there anything that makes them unique?

The problems of water quality that societies face are entirely due to the society itself. If you were to call New Jersey’s Department of Environmental Protection, you would find that we have actually done an excellent job of providing the New York City public as a whole with water quality that is frankly better than one would expect.

There have been beaches in New Jersey that closed recently because of problems with levels of bacteria.

I’ve been with the city for a short time compared to other places I’ve been, and I have to tell you, in light of all of my years of experience, the water, the estuary itself, is a heck of a lot cleaner now than it was 30, and 40, and 50 years ago. In the ’40s and ’50s, you really couldn’t fish in the harbor. And even in the ’60s and the ’70s, it was not the best place to fish. The fish are coming back.

Since the passage of the Water Pollution Control Act of 1972 and the billions that have gone into the development of our infrastructure for sewage treatment, and the better management of storm-water runoff, it’s made a huge difference in the water quality in cities like New York and Philadelphia.

I’m not going to go out there and tell you to swim there every day. I can’t guarantee that what I told you holds true for every mile of the Hudson. But there is a far better opportunity to have enjoyment than any time in the past, and an awareness by the public and by local and state officials is key.

ALBERT MONTAGUE

* Born in the Bronx.

* Professor at the School of Engineering, Temple University in Philadelphia, for 27 years.

* Served in the New York City Department of Environmental Protection from 1961-70.

* Earned a B.E. in civil engineering at New York University; an M.S. in civil engineering at New York University; and a PhD in Environmental Sciences at Rutgers University.

* Retired from the U.S. Environmental Protection Agency after 32 years of service.

* Served in New York Air National Guard as an aircraft mechanic.