Project Specifics

The Ryerson Creek Outfall (RCO) is the last remaining subarea in the Muskegon Lake, Michigan Area of Concern (AOC). Once the identified Beneficial Use Impairment (BUI) of the RCO (Degradation of Benthos) is addressed the Muskegon Lake AOC can be delisted. The project included a multi-phase pre-design investigation, feasibility study (FS), and remedial design (RD) to implement the recommended mitigation approach. The FS/RD and remedial action is being conducted as an EPA Great Lakes National Program Office (GLNPO) cost share partnership with our client and the Michigan Department of Environment, Great lakes, and Energy (EGLE). Additionally, GLNPO used the U.S. Army Corps of Engineers (USACE) as technical support.

Geosyntec Scope of Services

Geosyntec completed a FS for mitigating the Degradation of Benthos BUI. The recommended alternative included dredging of impacted sediment and replacement with sand with benthic substrate to promote recolinization. The FS included evaluation of dredging techniques and sediment management. Sediment was removed, dewatered, and conditioned prior to landfilling. The identified dredging technique was mechanical dredging with an evironmental clamshell bucket, gravity dewatering, and conditioning with an amendment such as Portland cement. Mechanical dredging was identified in part because of the limited water content of the removed sediment.

Geosyntec completed the RD of the FS recommended approach and in addition to sediment removal and processing and cover installation, the design included restoration of wetland areas disturbed during the remedial contraction. Muskegon Lake is connected to Lake Michigan and thus subject to the variation in water level seen within the Great Lakes which presented a challenge for the restoration design.

Geosyntec worked hand-in-hand with GLNPO and EGLE as a project partner and with USACE throughout the investigation and RD process, at times daily. Through this interaction we were able to identify and design a project that met GLNPO and EGLE requirements and could be implemented within the available funding. To complete the work and make the project a reality, Geosyntec contributed a limited amount of engineering design services; which allowed GLNPO and EGLE to match our contribution. Additionally, Geosyntec was responsible for applying for and obtaining joint EGLE/USACE wetland permits for both the PDI and remediation.

Notable Accomplishments

In addition to the technical aspects of the project, collaborating as a project partnership allowed Geosyntec to work as one team with EPA GLNPO and Michigan EGLE. The partnership prepared the Quality Assurance Project Plan, Field Sampling Plan, FS, and the RD. The result was a remedy acceptable to all parties, that could be implemented within the available funding, and has been substantially completed.

What is a Quick Qual?