Dartmouth College — Occom Pond restoration

Partner archive · Ecosystem restoration

100-year campus pond restored to full ecological health in two years — validated by university biology department.

Dartmouth College — Occom Pond restoration · Hanover, New Hampshire, USA · 10 September 2024

The challenge

Located adjacent to the Hanover Country Club golf course with no buffer zones, the pond was subject to continuous fertiliser and pesticide runoff — driving persistent eutrophication, recurring algal blooms, fish kills, and hydrogen sulphide odours. Decades of sludge had accumulated on the bottom.

The approach

A year-long MICROBE-LIFT® programme targeting shoreline, open water and bottom sediment — with the goal of reducing bottom solids, eliminating odours, controlling algal growth and improving water quality and clarity. Treatment ran May through October each year from 2006 to 2008.

Results

Confirmed by Biology Dept

Ecosystem restoration

Zero (entire programme)

Fish kills

Eliminated

Algal blooms

Eliminated

Odours (H₂S)

Despite 8–9 inches of above-average rainfall during Phase 1 — continuously reintroducing nutrients — the programme achieved significant bottom sediment reduction, complete odour elimination and zero algal blooms every treatment year. Full ecosystem restoration was confirmed by the Dartmouth Biology Department by end of 2007 — two years into a programme originally designed for five. Approved by the NH Department of Environmental Services. This remains one of ELI's most thoroughly documented open-water cases.