Superior officials outline options after emerald ash borer found in North End

Parks and recreation staff told the Superior Common Council on Aug. 20 that the emerald ash borer has been confirmed in the city's North End and recommended a range of options including selective tree treatment, staged removals and a public outreach campaign.

The council was shown maps and photographs of infested ash trees and given estimates of the scale and cost of response. "We confirmed a find of the bug in the North End on August 7," Parks and Recreation Administrator Morgan said during the presentation, noting quarantine rules that restrict movement of ash wood and firewood. Morgan said a 2009 tree survey shows about 3,000 public ash trees in streets, parks and the Nemadji Golf Course.

The presentation explained why action matters: ash trees provide ongoing, noncash public benefits (shade, stormwater uptake and air-pollutant removal). Morgan said an average 12-inch-diameter street ash in good condition is valued at about $1,470 per year in those services and estimated the city's 3,000 public ash deliver roughly $4 million in annual value while they remain healthy.

Morgan described options and tradeoffs: pesticide treatment that must be repeated (commonly every two years), staged removal of smaller or hazardous trees, and replacement planting. She summarized outside experiences: Milwaukee treats large numbers of public ash on a rotating schedule and pays roughly $35 per treated tree in-house; Minneapolis elected not to treat public trees and is removing them; Burnsville has been testing a different, lower-toxicity product. Morgan said the research does not yet prove a one-time cure or a point when treatments can stop.

On costs, Morgan gave order-of-magnitude figures and planning scenarios rather than firm bids. She said statewide averages put contracted removal at roughly $1 million to remove the city's 3,000 public ash and about $1.2 million to replace them if outsourced, and described a multi-year option that spreads removal, treatment and replacement across 2014'16 with sample annual budgets (roughly $300,000'$500,000 per year in the staff scenario). She noted Milwaukee's multi-year, in-house program costs about $1 million per year and compared that with an estimated $27 million cost to remove tens of thousands of ash there if done at once.

Morgan and the tree board described operational steps already in place: crews are removing only ash trees that meet an established criterion (about 50% canopy loss), trees that lean into roadways or homes, and ash with splitting bark; healthy ash are being left while the council considers policy. Morgan said crews had identified local hot spots (Nineteenth & Ogden; Seventeenth & John; Catlin Avenue; North 20th Street) and that the city is staging chip sites and working on wood-disposal arrangements.

Councilors asked for technical details and financial approaches. Councilor Olsen asked how the insecticide is applied; Morgan explained injections around the trunk or soil drench uptake and noted pesticide-ordinance limits for treatments in public rights of way. Councilor Finsland recommended scheduling a follow-up presentation; Clerk confirmed the item will return to the Aug. 20 agenda schedule for the Oct. 1 meeting for more information. Staff proposed a Committee of the Whole or Public Works review as options for more public-facing discussion.

Morgan said the Wisconsin Department of Natural Resources has circulated mortality projections showing a steep ramp-up in ash deaths a few years after initial infestation, and she noted that the city had arranged a conference call with Dr. Richard Hauer (University of Wisconsin-Stevens Point) to discuss treatment and valuation methodology.

The council did not adopt a citywide treatment or removal policy at the meeting. Instead, staff will return with additional cost-estimate scenarios, disposal options, and recommendations for council consideration at an upcoming meeting. Morgan said the tree board and staff will continue public outreach, door-hanger distributions and library informational meetings.

"We're leaving all of the healthy ash because we think you have some decisions to make," Morgan said, summarizing the staff approach to allow council deliberation. The council scheduled a follow-up presentation for Oct. 1 and directed staff to develop more detailed financial and operational options ahead of that meeting.

The council and staff also discussed coordination with Douglas County, which is managing timber-scale responses in its larger forest holdings and hosting a September meeting for the logging industry to address quarantine and transport issues. County cooperation may help with disposal and processing, but the city said urban and county forestry problems are operationally different and likely to require different responses.