Why would a man build a house with 30 bathrooms? That's one of the questions swirling around secretive billionaire Ira Rennert and the $100-million mansion he's building in New York.

As we told you last night, Rennert owns Utah's controversial MagCorp plant, which is listed annually by E.P.A. as America's Number One Toxic Air Polluter.

Environment Specialist John Hollenhorst has part two of his series.

Who needs a house with 30 bathrooms? That's what the neighbors in New York want to know.

And Rennert's critics in Utah question whether that extravagance is misplaced when his plant in Tooele County needs a major cleanup.

They're building it, in the driving rain and fog of Long Island. And it will be big, big, big.

Magcorp owner Ira Rennert is spending a hundred-million dollars to build it. Angry neighbors are trying to stop it. They love to rattle off the mansion's vital statistics.

Joseph Dilworth, of Southampton, New York, says, "The principle structure is 66,000 square feet. If you add the ancillary structures, I think we're up to something like 108,000 square feet."

Sheila Hoffman-Bialek adds, "There're going to be two bowling alleys, three basketball courts."

And, "There's parking within the garage complex for in excess of over 100 automobiles," according to Dilworth.

"If you count the guards' rooms and everything, there's probably closer to 40 bedrooms and baths."))

Chip Ward, of Grantsville, says, "And it will be the largest private dwelling in the United States, beating even microsoft's Bill Gates for that honor."

The Long Island neighbors, whose homes are far from cheap, say the giant house will complete the destruction of the area's rural character.

Linda Bird Francke told us, "This is the just sort of the icing on the cake. I mean, it's so over the top that it rather amuses me."

Rennert's critics say the millionaire has an 'edifice complex.' But Rennert's defenders say those wealthy critics have 'palace envy.' In fact, critics don't really believe it's a house under construction.

There are many theories. Rennert is really building a museum. Or a school. Perhaps a retreat for Israeli politicians or even a religious study center for conservative Orthodox Jews.

Joe Zicherman, also of Southampton, explains, "That's not my issue. My concern is, much more what it is not. And it is not a one-family home. There's no question about it. It's not a one-family home."

In Utah, critics question Rennert's priority.. spending a fortune on a fabulous mansion, but not enough on controlling Magcorp's pollution.

Ward says, "When you succeed as much as Mr. Rennert has, you also have a responsibility and an obligation to reciprocate. Give something back. That's the essence of good citizenship. And on that score, Rennert has failed utterly."

As a matter of fact, Magcorp officials revealed this week they're tentatively planning to spend $55 million to upgrade the plant and make it a lot cleaner.