AP: An environmental group says it has filed a Public Information Act request with Maryland’s Department of the Environment for records about a Berlin chicken farm it says is polluting waterways. The Waterkeeper Alliance has threatened to sue the Hudson Farm and Perdue Farms, which buys chickens from the farm. State officials said last month that a mound photographed by the group on the Berlin farm was treated sewage sludge, not poultry manure. MDE spokeswoman Dawn Stoltzfus says …