The Maryland State House, Annapolis. Photo by Jeffrey Porter/ For The Washington Post.

The Senate approved but altered a bill to double the flush tax for most residents, used for Chesapeake Bay restoration efforts, to $60 from $30. Supporters said the increase is needed to cover a shortfall in bay cleanup funds. In a surprising last-minute motion, however, a Western Maryland Republican argued that residents who are not in the bay’s watershed should not have to pay the higher tax. Del. Maggie McIntosh (D-Baltimore) said the House will agree with the amendment.

Legislators appeared on the verge of giving final approval to Gov. Martin O’Malley’s (D) initiative to curb sprawl by limiting developments that rely on septic systems. Slightly different versions of the bill have already cleared both chambers, both including a compromise that will keep ultimate land use authority in local hands. The Senate will decide Monday whether to agree with minor amendments in the House version.

A bill that won final approval will make Maryland the first state to ban arsenic in chicken feed. Supporters argued the measure would protect public health and the environment; opponents said the ban was unnecessary because Pfizer suspended sales of roxarsone, the drug in question, last year after the Food and Drug Administration found low levels of inorganic arsenic in some chicken livers.

In a lighter development, Marylanders will be allowed to compete for cash and prizes in fantasy sports leagues under a bill explicitly exempting such activities from state anti-betting laws. Supporters of the legislation said Maryland law is ambiguous on the issue of pay-to-play fantasy football and other leagues, which federal law and most states allow. The bill passed both chambers with little opposition.

Lawmakers unanimously approved O’Malley’s initiative to put economic pressure on Iran because of its nuclear activities. The legislation will divest the state’s pension system from companies that do business in Iran and follows the lead of California and Florida, which took similar actions after President Obama signed the Comprehensive Iran Sanctions, Accountability, and Divestment Act of 2010.

Nonviolent offenders on parole or probation would be rewarded for staying out of trouble under a bill that won approval in the Senate. Compliance would result in reduced supervision time, which supporters said would lessen the burden on overtaxed parole and probation workers. Opponents tried unsuccessfully to extend an exclusion provision to all felonies, not just violent offenses. Another version of the bill already passed the House.

After a heated debate, the Senate rejected a bill that would have required electric and gas companies to provide customer account information on request by a supplier. The measure had received unanimous support from the House, but opponents in the Senate took issue with personal information being used for marketing.

Under two consumer protection measures that received near-unanimous approval from lawmakers, pet stores could have to reimburse costs for dogs that die or become ill soon after purchase, and the state’s beekeepers could bring suit against honey sellers that use cheap additives, such as high-fructose corn syrup, and don’t clearly label the extra ingredients on the front of the jar.