The Lyme-Old Lyme Board of Education is moving forward with a plan to build a more than $2 million artificial turf athletic field, a project school officials say will conserve groundwater without placing a burden on taxpayers. For the past two decades, the district has typically funneled 1 percent of its annual budget into the fund to help finance larger projects and avoid budget increases or the need to bond, he said. The fund balance is currently $1.7 million, but officials expect it to increase to more than $2.5 million by next year — enough to pay to install the field. The district hired Milone & Macbroom for $23,800 in October to begin designing the field. The board and the firm will now complete the design before seeking bids for the work.