BP Exploration Alaska and Hilcorp Alaska have agreed to pay fines after spilling oil and waste on the North Slope.Listen nowCleanup personnel wipe oil from well piping on May 4, 2014 where a BP Exploration Alaska pipe ruptured and contaminated nearby tundra. (Photo by Don Fritz/ADEC)The Environmental Protection Agency announced the companies will pay $130,000 in federal penalties.According to the EPA, the Clean Water Act violations by both companies affected Arctic wetlands that support wildlife like caribou, ptarmigan and geese.EPA spokesman Mark MacIntyre said the North Slope is one of the harshest environments where companies operate in Alaska. It’s also one of the most ecologically sensitive.“We know that the tundra is kind of like a big sponge and is completely overlaying water that drains off and runs to various tributaries to rivers and then rivers to the sea,” he said.Hilcorp had a breach in a production line in its Milne Point field. The leaky pipeline caused nearly 10,000 gallons of crude oil and water to spill onto about an acre of land. The company will pay $100,000 to the EPA.BP will pay $30,000 in federal penalties for spilling 700 gallons of waste onto 33 acres of tundra and gravel pad. That spill was caused by a frozen rupture in one of the company’s lines in Prudhoe Bay.Piping showing oil from the BP spill in Prudhoe Bay on May 2, 2014 in Alaska. (Photo by John Ebel, ADEC)MacIntyre said spill cleanup on the North Slope can be complicated by winter weather. Hilcorp response crews had to struggle through blizzard conditions while BP workers had to remove acres of contaminated snow.“A lot of times, frankly these spills happen at the worst time of the year, when it’s the coldest, when it’s the darkest, when (it) really puts people at risk in terms of responding and trying to fix things when they spill,” MacIntyre said. “So it’s really in nobody’s interest to have anything spill.”Neither company agreed to interviews about the incidents. Both sent prepared statements.Hilcorp spokeswoman Lori Nelson said it is proud of its response to the spill and inspected other similar pipeline sections as a result of the incident. While BP spokeswoman Dawn Patience said the company has worked to strengthen safety and risk management.EPA relies on the companies to report spills. After the agency notifies a company it is considering a fine, MacIntyre says the companies can weigh-in.“They come in and negotiate with us and we end up with a final penalty,” he said.Each case is resolved differently. Sometimes the money goes to the state, sometimes to the federal government. In BP’s case, the company will pay $30,000 in penalties directly to a federal fund that is used to pay for cleanup when spills occur and the responsible party is either unknown, or refuses to pay.BP also settled its case with the Alaska Department of Environmental Conservation after its spill. It will pay the state $100,000.Hilcorp could still face further fines from its Milne Point spill. A spokeswoman from DEC said the state is investigating the incident and its case is still open.Both companies have reported dozens of spills in Alaska since 2014, but most of the discharges are minute amounts of fuel or oilfield chemicals.