The Board of Health of the Town of Shrewsbury (the Town) contracted GZA GeoEnvironmental, Inc. of Norwood, Massachusetts (GZA) to conduct a feasibility study for the restoration of Jordan Pond. Funding for this study was provided through a grant by the Commonwealth of Massachusetts through the Department of Environmental Management’s (DEM) Lakes and Ponds Program. The purpose of this two phase study is to examine the potential for the restoration and improvement of water quality and other conditions at Jordan Pond relative to human usage and aquatic habitat. Phase 1 involves basic data collection, modeling, and the preparation of a Pond Management Plan. Phase 2 will explore in detail proposed methodologies for in-Pond remedies and expected
outcomes.

Jordan Pond is a small (21-acre), shallow (9.3 feet maximum depth) pond located entirely within the Town of Shrewsbury. The contributory watershed to Jordan Pond is approximately 195 acres, consists largely (60 percent) of mid- to high-density residential property, with some commercial land use (10 percent), while the remainder (30 percent) is forested. Jordan Pond has historically been utilized as a recreational resource for swimming, boating, and fishing. Jordan Pond has a history of documented water quality impairments and management actions dating back over 50 years.

The two primary issues of concern at Jordan Pond are an overabundance of aquatic vegetation and bacteria concentrations, which exceed state swimming standards. GZA’s field investigations have confirmed the severity of these problems. The pond is subject to almost 100 percent coverage of the rooted aquatic plant Elodea Nuttallii (commonly known as waterweed), as well as significant blooms of Bluegreen algae. GZA’s limited water quality sampling also documented bacteria concentrations in the Pond, which exceed State swimming standards.

GZA’s analyses indicate that the nuisance aquatic vegetation problems at Jordan Pond are largely a result of excessive watershed nutrient loading from non-point sources such as lawn fertilization and that the bacterial concerns are likely due animal waste from waterfowl (direct to the pond) and domestic pets (indirect from stormwater). Prolific weed growth is also due to nutrients bound up in the Pond sediment, a long-term problem.

To address these root causes of the plant and bacteria impairments, GZA recommends that the Town of Shrewsbury and the Jordan Pond Watershed Association work with the residents of the Jordan Pond watershed to reduce the nutrient, contaminant, and solids loading to Jordan Pond. The recommended watershed controls include:

1. Expand existing public education, awareness, and outreach programs.
2. Develop additional programs as necessary, including informational brochures and
   signage around the Pond. Educational efforts should focus especially on turf
   management, pet waste disposal, garbage disposal use, and hazardous materials
   disposal.
3. Modify street sweeping and catch basin cleaning programs to operate on an annual
   cycle. Streets within the Jordan Pond watershed should be given high priority for
   maintenance in the spring so that much of the sand from winter applications can be
   removed before spring storms wash it into the Pond.
4. Enforce the ban on motorized vehicles on the trails adjacent to the Pond.
5. Relandscape the beach area to minimize erosion (see Section 10.20).
6. Hold workshops on turf management and consider the creation of a rebate system for the purchase of phosphorus-free fertilizers.
7. Stencil catch basins in the watershed.
8. Install “pooper-scooper” signage and enforce pet waste disposal regulations.
9. Install an in-line stormwater treatment device (e.g.: Stormceptor) at each of the two concrete discharge pipes at the northern end of the Pond.
   

GZA believes that these measures will help to reduce nutrient and bacteria loading into the Pond. However, given the urban nature of the watershed and the long history of problems, GZA believes it is unlikely that these measures will be successful in ensuring consistent compliance with State water quality standards for swimming. GZA therefore recommends that the Town strongly consider a permanent suspension of the use of Jordan Pond as a swimming facility. We recommend that the Town and residents instead focus on restoring the Pond for use in secondary contact recreation activities such as boating, fishing, walking, birdwatching, etc. This approach was discussed and agreed upon during the Project Kickoff Meeting.

In addition to ongoing nutrient loading from the watershed, GZA’s analyses indicate that the sediment in the Pond is also likely to be a significant source of nutrients that is driving plant growth in the Pond. Phosphorus-rich organic sediment was found to be an average of 5.4 feet thick over the entire pond and in excess of 12 feet thick in some locations. This sediment represents a source of nutrients, which will continue to facilitate heavy plant growth in the Pond even if inputs
from the watershed are curtailed. Additional, in-pond actions are therefore required. Three broad categories of in-pond actions are possible: 1) No Action; 2) Small-scale management actions (such as repeated herbicide applications and/or hydroraking); and 3) Intensive, large-scale management actions (such as dredging or water diversion).

A low-cost in-pond management option for Jordan Pond would be to continue with repeated annual herbicide/algaecide applications. An endothall-based treatment such as Hydrothol 191 is recommended. Hydrothol costs approximately $300 to $500 per acre treated, or $6,000 to $10,000 for complete coverage of Jordan Pond, excluding permitting costs. Herbicide treatment has been used with reasonable success in Jordan Pond in the past to control aquatic vegetation, but the benefits of such treatments are short-lived. Thus, annual or bi-annual (every other year) herbicide/algaecide treatments would be most effective. Mechanical aquatic plant control, such as hydroraking, is another small-scale, short-term management option, and may be useful in combination with herbicide/algaecide treatments. In the absence of more involved in-pond management techniques, herbicide/algaecide treatments are the recommended management option for Jordan Pond, but it should be recognized that this option will require continual retreatments and management efforts.

A more long-term (albeit more expensive) in-pond management program at Jordan Pond would need to deal with the sediment as an on-going source of nutrients in the Pond. Dredging is a potential option, but GZA believes that a process known as “reverse layering” which involves the placement of a clean sand layer over the top of the organic sediments represents a potentially less expensive alternative with comparable efficacy. GZA recommends that Phase 2 of this study, the Preferred Alternative Feasibility Study, focus upon the specific feasibility of implementing reverse layering at Jordan Pond.