Hawaii drivers arrested on a repeat DUI offense would have to agree to stop drinking alcohol for at least 90 days and wear an ankle bracelet that would alert a private company if they have a drink if they want to be released from jail on bail, under a bill that has so far this year sailed through the Legislature.

The DUI offenders would also have to pay for the device, which could cost about $360 per month and emits a light buzzing sound every 30 minutes as it checks the skin for alcohol excretions, according to the leading manufacturer of the ankle monitor.

The bill is being championed by the Honolulu prosecutor and a Denver-based company called SCRAM Systems, which makes the ankle bracelets. The measure has passed the full House and three Senate committees. It will likely go to conference committee, where select House and Senate members review the bill — one of the final steps before a bill can gain final passage in the Legislature.

While House Bill 306 is being touted as a new way to crack down on drunken driving, which in 2015 was a factor in about 51 motor vehicle deaths in Hawaii, it’s sparked opposition from a pair of unlikely allies: the Public Defender and Mothers Against Drunk Driving Hawaii.

Hawaii’s Office of the Public Defender argues that the bill is unfair to low-income residents who could find themselves sitting in jail for a prolonged period of time if they can’t afford the cost of the devices or aren’t able to stop drinking because of alcohol addiction.

“If you got the money, you are only going to spend a few minutes in jail, but if you don’t you could spend a lot longer. That is our objection,” said Tim Ho, chief deputy public defender. “It carves out two categories of defendants: those that have money and those that don’t.”

Drunken drivers could have the costs waived if they are determined to be indigent, but Ho said the bill doesn’t spell out how that would be determined, and that the high cost of the devices could be prohibitive for not just indigent residents, but lower- and middle-class residents on tight budgets.

The bill is also being opposed by Mothers Against Drunk Driving Hawaii, commonly known as MADD, which usually sides with prosecutors when it comes to measures targeting drunken drivers.

“It’s very awkward for us to go against the prosecutor’s office,” said Arkie Koehl of MADD Hawaii, a member of the group’s national board of directors. “We don’t feel comfortable about it at all.”

Koehl said that MADD Hawaii has a number of concerns about the alcohol-monitoring devices, including their cost. If they are mandated, they could also edge out ignition interlock devices, which require repeat offenders to do a blow test for their vehicle to start.

The ignition interlock devices cost about $3 a day. The ankle bracelets could cost about $12 a day, in addition to an installation fee that could be as high as $100, according to information from SCRAM.

The SCRAM ankle bracelets also can’t be submerged in water, so the person couldn’t take a bath or go swimming. If they are damaged, this could add to their costs.

If the device is submerged in water, “it will be flagged as an attempt to defeat the device and will be handled in the same manner as a tamper or obstruction,” according to SCRAM’s website. “You will also be financially liable for any damages caused by submerging or damaging the SCRAM CAM Bracelet.”

Koehl, as well as the public defender’s office, said it’s unlikely that drivers would want to pay for the ignition devices if they are mandated to wear and pay for the ankle bracelets.

The ankle bracelets can’t stop a person from driving if they are drunk, noted Koehl.

Since the ignition interlock devices began being used in Hawaii, vehicle fatalities have declined by about 23 percent, according to MADD Hawaii — progress that the group doesn’t want to see reversed.

The bill has “been pushed through committee after committee. Each time, we have been getting more and more upset about it,” said Koehl. “Each time, there has never been a proper discussion about how it would work with the ignition interlock.”

Koehl also said that MADD Hawaii is upset that the bill wasn’t first vetted by the state’s Impaired Driving Task Force, which is administered by the state Department of Transportation.

While the state Transportation Department initially supported the bill, officials later said in testimony that they too have concerns about the measure that remain unresolved. Both MADD and the Transportation Department are recommending that the bill be deferred until next year.

Honolulu Prosecutor Keith Kaneshiro, who asked that the bill be introduced, declined an interview request. But in written responses to questions, staff from his office said that the idea for the measure came after Kaneshiro met with SCRAM officials, at their request, late last year.

Kaneshiro’s office notes that there are about 1,000 arrests for repeat drunken driving annually.

“Not only would this save lives, but it would generally assist in making our community a safer place to live and work,” his office wrote in testimony supporting the bill.

SCRAM has also testified in favor of the bill and hired well-known Honolulu lobbyist Bob Toyofuku.

Mindy Huddleston, director of industry and government monitoring for the company, said that nationally there is a trend within the courts to order sobriety in drunken-driving cases.

“Courts have been permitted to order sobriety for years, but unless you can continually test for it, you don’t know if that person is sober during that period,” she said. “This is the only way you can ensure they are being sober.”

The company’s tracking system is monitoring about 21,000 people throughout the country on any given day, according to the company. The data from the bracelets go to the company’s monitoring system in Denver.

The bill is written so that one company would receive the contract to administer the devices. Huddleston said SCRAM does not intend to bid on the contract, but has been in contact with a service provider that is expected to bid if the bill passes. That company, which she declined to name, is expected to purchase the ankle bracelets from SCRAM.