The Agency of Agriculture, Food and Markets has filed a final update to farm water quality rules that went into effect Friday. But some environmental groups say the rules don’t go far enough to address pollution from existing on-farm tile drains.
The new rules, which were required by the state’s 2016 Clean Water Act, address runoff of phosphorus and other nutrients from water flowing out of on-farm “subsurface tile drainage,” or tile drains.
Tile drains are systems of pipes installed under crop fields to quickly drain wet fields. While tile drains, installed since the 1800s, have helped farmers grow crops in fields that otherwise would have been too soggy to use, scientists now know that the drains can provide another path for nutrient laden water to make its way into nearby water bodies. The impact of tile drains on water quality varies, and relates to whether a field has high phosphorus levels from manure or other fertilizers.
A joint report from the Agency of Agriculture and the Agency of Natural Resources states that tile drains “can be a significant contributor to the overall phosphorus load in heavily agricultural watersheds.” Excess phosphorus is the main cause of the cyanobacteria blooms that have plagued Lake Carmi and parts of Lake Champlain, leading to the Environmental Protection Agency mandates that the surrounding watersheds lower phosphorus pollution going into the lakes.
The Agency of Agriculture initially filed the rule amendment with the Legislative Committee on Administrative Rules on August 21. The legislative body voted to approve the rule earlier this month following three committee hearings on the subject.
The rule updates include:
— manure stacks cannot be within 100 feet of a tile drain.
— combined animal feeding areas cannot be built over tile drains.
— no new surface inlets, which are pipes that lead directly from the top layer of a field to an outlet, can be installed.
— rodent guards must be put on new drains installed after the first of the year and other nutrient management practices.
— additional manure and nutrient application requirements in fields with tile drains that have high phosphorus levels.
Vermont Natural Resources Council, Conservation Law Foundation and the Lake Champlain Committee do not feel the rule amendment goes far enough, said Jon Groveman, policy and water program director for VNRC. He said that while the Agency has taken “some steps” to reduce nutrient pollution from new tile drains, the groups do not feel the updates do enough to address existing tile drains.
Groveman said a “meaningful rule” would have required farmers to report where existing drains are and stop discharges.
“If we’re going to clean up our waters, this is weak, weak sauce,” he said. “We don’t think this meets the spirit of what the Legislature intended.”
During legislative committee testimony this September, Laura DiPietro, director of the water quality division for AAFM, responded that eliminating old surface inlets was impractical and unsafe.
“The old systems were never designed thinking about pulling them out one day, and infrastructure and other things have been built around those items,” said DiPietro. “So making just a blanket statement to say ‘eliminate or remove,’ the impact of that could be dire in some instances, causing flooding or other challenges to (nearby) homes.”
The groups are considering appealing the rules, but Groveman said that the legislative committee’s vote in favor of the amendment would make it challenging to win in court.
