A government witness in a trial to determine civil penalties against BP for the 2010 Gulf of Mexico oil spill says the disaster hurt a wide array of industries over a broad geographic area.

Charles Mason also testified Thursday that the harm was only modestly countered by BP’s spending and investment in the region.

U.S. Justice Department attorneys are pushing for the maximum $13.7 million Clean Water Act penalty for BP: $4,300 for each of the 3.19 million barrels of oil that presiding U.S. District Judge Carl Barbier has ruled were discharged as a result of the disaster. BP says the figure should be less, arguing that it already faces $42 billion in costs associated with the spill.

Cross-examining Mason, BP attorneys suggested his analysis failed to consider BP’s positive effect on the community, through the claims process and as a major employer.

BP lawyers also said the analysis lacked data and focused primarily on effects on tourism in Mississippi and Florida.

Oil from BP’s Macondo well spewed into the Gulf for 87 days following the April 20, 2010, explosion of the Deepwater Horizon offshore rig, which killed 11 workers.

What is expected to be a three-week trial on Clean Water Act penalties opened Tuesday. Barring a settlement, a ruling is not expected until April at the earliest.

In addition to environmental, social and economic effects on the Gulf, Barbier also is considering evidence on how a large penalty would financially affect BP Exploration and Production, the BP PLC affiliate that operated the well. Also at issue is whether possible financial assistance for BP Exploration and Production from other BP entities should be a factor in the penalty decision.