INDIANAPOLIS (AP) — Ambiguous water quality rules at issue in last year's uproar over a new water permit for BP's Whiting oil refinery will be clarified and approved by December, Indiana's top environmental regulator said Friday.

Environmentalists who attended a meeting Friday on the so-called "antidegradation" rule, however, said they were surprised that the new rule wasn't ready for review yet.

Gary environmental activist Lee Botts said she and her colleagues expected that the draft rule would be released Friday. Botts, 80, made the nearly 3-hour trip to Indianapolis to attend the meeting, which ran 50 minutes.

"It's a long trip. Next time, we'll ask for confirmation that we're really going to have something to talk about," she said.

The Indiana Department of Environmental Management has been working for months on the revised rule, which comes into play in water permit requests for new or increased pollutant discharges into waterways.

Unlike the current rule, which covers only northern Indiana's rivers and streams that are part of the Great Lakes watershed, the new rule will cover all of the state's waterways, said IDEM Commissioner Tom Easterly.

Easterly said he and his staff didn't want to present the draft rule at the meeting because it wasn't ready for review by environmentalists, industry and municipal officials who are closely following the issue.

"The language wasn't clear. It has to be understandable to me before I'll send it out. Otherwise we're going to be spend time arguing over misunderstandings instead of what the language says," he said.

Aside from Botts, four other activists who attended the meeting expressed disappointment that the meeting amounted to state officials presenting background on the rule and a timeline for their goal of getting the new rule approved by December.

"All these people drove, in the snow, to get to this meeting because we thought there would be something important for us to discuss, and there wasn't," said Rae Schnapp, the Hoosier Environmental Council's water policy specialist.

Schnapp questioned whether IDEM will be able to get the new rule in place by year's end.

"They said they were going to be aggressive, but they're already behind schedule," she said.

IDEM spokeswoman Amy Hartsock said the agency "did not a promise a draft of the rule at this meeting" and that the agency will issue the draft when it is ready.

James Barnes, the former dean of Indiana University's School of Public and Environmental Affairs, released a report in December on his analysis of the regulatory process Indiana used to approve a new wastewater permit for BP's Whiting refinery.

He concluded that the permit — which allowing the refinery to increase its pollution discharges into Lake Michigan — fully complied with federal and state laws — despite protests raised in other states that reached the floor of Congress.

But his report blamed the uproar over the permit largely on the state's antidegradation rules, which he called inconsistent and incomplete. In particular, Barnes said Indiana currently has two sets of antidegradation rules for Great Lakes waters.

One of those are for high-value waters that are part of the Great Lakes system, while the second applies to higher-quality waterways.

Barnes found that the rules for the high-value waters require an analysis that looks at the steps that could be taken to minimize or prevent effects on water quality. But he found that the second set of regulations — the one that applied in the case of BP's permit — has no such requirement.

That, Barnes concluded, made it difficult for activists and the public to determine if the pollution increases the permit would allow were truly necessary and that BP had examined all possible ways to cut the pollution discharges.

In August, two months after the permit was approved, BP announced that it would either find a way to stay within the limits set in its previous discharge permit or drop the expansion plans for the refinery about 20 miles southeast of Chicago.