LYNN – A school bus company owner is not protesting a federal environmental agency fine against his firm for excessive idling, but John McCarthy disputed federal claims that a bus lot in Lynn was among those cited by federal officials.The Environmental Protection Agency on Monday announced it fined bus operator NRT $33,000 for excessive idling in bus lots, including one in Lynn, by company drivers. The agency?s statement said the company violated state-set limits enforced by the federal government on how long a bus can remain stationary with its engine running.?Diesel exhaust is a serious health concern. Reducing idling helps protect children?s health,” an agency press release quoted EPA regional administrator Curt Spalding as saying.Based in Methuen, NRT?s operations include a public school bus lot off Liberty Street in Lynn.The EPA statement indicated a federal inspector earlier this year “observed NRT school buses idling for extended periods of time” in lots in Lowell, Lynn, Wilmington and Methuen.McCarthy called the Lynn lot?s inclusion in the list “inaccurate.”But EPA spokesman David Deegan said the agency “definitely has documentation” of idling occurring in the Lynn lot. Deegan praised NRT?s response to idling concerns presented to the company by federal officials as part of the fine and settlement with NRT.NRT agreed under the settlement, according to the statement, to make drivers aware of idling limits, post anti-idling signs and require managers to check company lots for idling buses.?NRT is very responsive about doing the right thing and moving forward,” Deegan said.McCarthy called the federal fine and agreement “all in all, a good decision by the EPA,” and said the fine amount reflects efforts the company to ensure its drivers obey idling limits. He said company representatives discussed with federal officials difficult situations bus drivers face in obeying the limits.He said drivers are aware of excessive idling rules but said they must also ensure buses are warm enough for students. Maintaining a 56 degree temperature or removing ice from windows can require more idling.?They don?t take into consideration our obligation to the students,” McCarthy said.NRT will install block heaters in 200 buses, according to the statement. McCarthy said the heaters warm up buses prior to students boarding the vehicles.An idling school bus consumes about a half-gallon of diesel fuel an hour and diesel exhaust can cause or aggravate, according to the statement, health problems such as asthma in children.?Taking easy and common-sense steps to avoid excessive idling helps to save fuel and money, and reduces unnecessary air pollution including greenhouse gases that contribute to climate change,” the statement quoted Spalding as saying.