Dear UNH Extension Team, I’m a homeowner in North Hampton, and I’m reaching out for assistance regarding a Japanese knotweed contamination issue that I’ve identified on my property. I’m looking for expert guidance on containment and eradication before this becomes a larger ecological threat. Earlier this month, I had approximately 135 yards of topsoil delivered and spread across a 15,000 square foot area. Within two weeks, I began identifying Japanese knotweed shoots emerging from that soil. Every shoot has been manually removed and incinerated on-site in a controlled fire pit, and I am actively patrolling the entire zone daily. The soil was spread shallowly—generally no more than 2–3 inches deep—and was laid primarily over compacted fill. I want to note that the topsoil was spread primarily over fill that was delivered to the same location last fall—approximately 8 truckloads (~128 yards) in total. The purpose of the topsoil was to stabilize the fill and support grass growth across the newly graded area. While I have not observed knotweed emerging from the fill itself, I am concerned that rhizome fragments may be present beneath the topsoil and could remain dormant longer. Most of the fill is now covered, but there are a few areas where it remains exposed. I continue to monitor both layers closely. Of particular concern is the fact that my property directly borders over 110 acres of protected conservation land, including forest and marshland that ultimately drains into the Winnicutt River. Beyond that lies a much larger contiguous area—possibly 1,000+ acres of wetland and undeveloped habitat—that includes the wellfields for Hampton Waterworks, which supplies drinking water to both North Hampton and Hampton. Given the sensitivity of the area and its ecological and public water value, it’s essential that this infestation be addressed before it spreads beyond control. I’m seeking the following: A consultation with someone experienced in knotweed identification and containment Guidance on best practices for surveillance and eradication under these conditions Information on what responsibilities I may have under state policy Clarification on whether the supplier must be reported, and how such cases are typically handled I have photographic and video documentation, including images of the rhizomes and shoots. I’m not looking to escalate this unnecessarily, but I want to ensure that I’m doing everything possible to contain the problem before it becomes unmanageable—both for my land and the surrounding ecosystem. Thank you for any help or direction you can provide. Sincerely, Janice Kierstead<personal data hidden> North Hampton, NH