City staff presented an update on July 14 on the poplar tree plantation established near Highway 6 to assist with wastewater treatment and nitrogen uptake, saying the site is being harvested, chipped and prepared for soil amendment and replanting.

The nut graf: The plantation was originally intended as a biological land-application system tied to Chehalis’s treatment-plant discharge strategy; staff told the council the plantation has reached the end of its effective life and requires harvesting, significant soil preparation and irrigation replacement to function again as designed.

At the meeting a staff presenter reviewed the site history and technical background: the plantation was planted in 2003 as a hybrid-poplar system intended to take up large amounts of nitrogen from treated wastewater during low river-flow months, as an alternative discharge option spelled out in the earlier Total Maximum Daily Load (TMDL) and MPDES (NPDES) permit negotiations. Staff said the plantation’s design capacity is about 3,500,000 gallons and that the site contains roughly 11 units and about 8,800 trees planted originally; the site area remaining to harvest was described as roughly 40 acres.

Staff described a three-phase plan: harvesting (already under way, with trees being chipped on site), soil amendment and reforestation. The presenter said contractor harvesting costs are roughly $15,000 and current pulp-market returns are low (approximately $22 per ton), and that the city used in-house chipping to reduce expenses by an estimated $2,500–$3,000. For soil preparation staff cited contractor pricing of about $60,000 to rotovate, grind stumps 4–10 inches below grade and produce a workable planting surface. Staff also described irrigation piping on site — about 60,000 linear feet — and estimated replacement cost roughly $1.00–$1.25 per foot; staff said that irrigation is important because earlier mortality in one unit appeared linked to lack of reliable irrigation during the first three years after planting.

To reduce long-term maintenance, staff said the city plans to plant “whips” (4–6 foot poles) rather than small saplings; staff gave unit cost estimates of about $1.50 per whip (saplings estimated at $0.75–$1.25 each) and said that planting larger whips should reduce weed-control labor. Staff also said replanting with a GPS-guided contractor would preserve the original 14-by-14 spacing and that upgrading irrigation would allow periodic flooding of units to aid weed control.

Staff noted policy and regulatory context: the original TMDL negotiation and the 2000 consent decree among point dischargers shaped the system’s development; staff said they will discuss permit terms with the Washington State Department of Ecology as the city seeks a new permit and to clarify when and how discharges can move between the river and the tree farm.

Council members asked operational and financial questions about tonnage yield from the chip operation, safety during harvesting on Highway 6 frontage and the possibility of selling logs to local processors. Staff said some frontage trees were harvested for safety reasons and acknowledged there were some traffic accidents despite traffic control measures; staff also said they will follow up on a question about expected tons of chips and provide that figure to council staff.

Ending: No final policy vote was requested; council received the staff update and staff said they will continue permitting conversations with Ecology and return with additional cost and tonnage details as they become available.