A bill designed to streamline the process under which severely mentally ill people can be ordered to get outpatient psychiatric help got final approval from lawmakers Tuesday.

The measure now heads to the governor.

A host of advocates, including those who work with chronically homeless people, supported Senate Bill 310, saying it’s meant to help people who can’t help themselves.

They also argue the existing involuntary outpatient law is rarely used because it’s vague and overly broad.

"It was very cumbersome," said Connie Mitchell, executive director of the Institute for Human Services, a homeless service nonprofit organization.

Mitchell said the new measure will allow providers to serve the most difficult cases.

Severely mentally ill people are "literally dying" on the streets, she said. "My hope is that this will very much facilitate a lot more access to treatment."

The measure got unanimous support from both the full House and the Senate on Tuesday.

Even before the bill was passed by both chambers, advocates were talking about its implementation.

Barring a veto by the governor, the law would go into effect Jan. 1.

The delay was aimed at giving the courts time to determine how the outpatient orders would be handled.

Marya Grambs, executive director of Mental Health America of Hawaii, said service providers have been gearing up in anticipation of the measure’s passage and are ready to step in.

She said the bill is ultimately meant to help severely mentally ill people who are "using the system in a cyclical way" — going in and out of hospitals.

"These are people who don’t know they’re ill," Grambs said. "We think we’re going to save lives" with this bill.

Under the proposal, any "interested party," from a relative to a case manager, would be able to file a petition with Family Court alleging a person meets the criteria for treatment.

The court could order someone to undergo treatment if that person has a mental illness, likely has an inability to "live safely in the community," has a history of inpatient mental health treatment or of presenting a danger to themselves or others, and has a history of "lack of adherence" to beneficial treatment.

The existing definition of those eligible for involuntary outpatient services does not include the "lack of adherence" requirement or the provision that they are unlikely to "live safely" in the community.

(The bill also scraps the term "involuntary outpatient," instead opting for "assisted community treatment.")

Grambs said that, most important, SB 310 would allow law enforcement or other authorized parties to transport those who fail to comply with treatment orders to a mental health program in hopes of getting them to comply.

A person who continues to refuse treatment and does not pose a harm to himself or others will be released. But advocates hope that putting the mentally ill through the process will nudge a large number of them to agree to stick to treatment.

Those committed to a hospital for being a danger to themselves or others already can be forced to take medication with a court order.

Advocates say it’s difficult to say how many people would fall under the new measure in its first year. Estimates range from the low 20s to the mid-50s.

At least 41 states have involuntary community treatment statutes, according to Mark Mitchell, mental health branch administrator at the state Department of Public Safety.

The proposed changes to Hawaii’s law would bring it in line with what other states use, Mitchell has said in testimony.

There was little opposition to the version of the measure approved Tuesday, though the Office of the Public Defender did oppose it, saying it impinged on individual rights.

State Rep. Della Au Belatti, chairwoman of the House Health Committee, said on the House floor Tuesday that SB 310 was the result of a lot of discussion — and compromise — among providers, civil liberties advocates and state officials.

The measure, she said, "really represents a step forward in how we can help our mentally ill residents in this state," she said. "The bill … we’ve delivered is something that we can all be proud of."