Site restoration construction completed: June 2013.
Krejci Dump Site Clean-up Regrading and Restoration, Cuyahoga Valley National Park
Project Description The Krejci dump site historically received thousands of tons of industrial waste and was classified as a CERCLA/Superfund hazardous waste disposal site. The U.S. Department of Interior/National Park Service (NPS), who originally purchased the property, ultimately assumed the remediation oversight role from U.S. EPA. NPS retained EQ to remediate the site and restore it to “pristine” natural conditions.
Project Approach During the remedial phase of the project, EQ retained NTH Consultants, Ltd. (NTH) to assist with environmental sampling using a multi-incremental sampling approach to help assess whether contaminated soils were adequately removed. NTH also assisted with various geotechnical matters. NTH has been most involved with engineering for several activities to complete the restoration. NTH worked with the NPS for EQ along with a multidisciplinary team of engineers, biologists, ecologists, geologists, and environmental scientists.
Design activities completed by NTH have included:
Preparation of site restoration/regrading engineering drawings and an accompanying narrative document;
Hydrologic modeling using HEC-RAS software, with input including 60 years of historic climatological data;
Using hydrologic model output to perform long-term erosion predictions in support of the engineered regrading features;
Designing wetland features by incorporating findings of the HEC-RAS hydrologic modeling and hand calculations which simulated discharge features from the wetlands;
Designing check dams and other rock features with locally-mined siltstone to protect steep ravines and rock protection features.
During construction, NTH worked with EQ and the NPS to perform the following construction management activities:
Reviewing submittals erosion control rock materials, and seed mixes
Tracking soil erosion control placement, rock quantities, soil quantities, and regraded surface grades
Address changes during construction including redesign of a variety of ravine and wetland features
Preparing daily field reports to document the aforementioned construction elements
Overseeing site-survey activities and reviewing final grade surveys versus the design
Overseeing soil compaction and soil moisture data;
Completing daily field reports
NTH is on call to respond to engineering-related issues that may arise during the post-construction monitoring of the restoration features such as rock-check structures and the engineered wetlands.
Results To document the construction, NTH prepared a construction documentation report including a compilation of the as-built survey, the daily reports, soil compaction records, erosion control/seeding records, and other data. The report was submitted to the NPS to demonstrate that the project was completed in accordance with the restoration design documents approved by the NPS.