D&K engineers, through an assignment for on-call Soil Conservation services with NRCS, designed a retention structure and disposal field for 2,000-gallons-per-day of milking center wastewater. The retention structure consists of a multi-chamber reinforced concrete tank with a Clearspan fabric structure cover and was designed to be accessible by standard farming equipment for removal of accumulated sediment, fat cake, and sludge. D&K engineers designed disposal of wastewater utilizing a Presby Advance Environmental System (AES) subsurface disposal field, including 2,500 ft of AES piping. The wastewater disposal system includes gravity and forced mains for transferring wastewater. The existing manhole pump station was reused to serve as a new retention structure and the existing sediment basin and disposal lagoon were retained as an emergency back-up system.
Sugar River, NRCS NH
D&K engineers, through an assignment for on-call Soil Conservation services with NRCS, performed site investigation, design, permitting support, and construction observation for river bank stabilization and installation of a shallow wildlife pond on and adjacent to the Sugar River. Riverbank stabilization included the use of natural sub-angular boulders to armor the toe of slope, while providing pockets of shelter for aquatic organisms. Riparian vegetation was restored on the upper bank. Project was completed under the Wildlife Habitat Incentives Program (WHIP).
The pond was designed and built with zones of varied depth and vegetation. A rounded L-shape was designed to blend naturally into the landscape and avoid an adjacent wetland. Wetland delineation was performed for avoidance, minimization, permitting, and mitigation purposes. A landscape plan was developed to help stabilize and restore the riverbank and to provide native vegetation that provided wildlife value at the pond. The scope of services included field survey, wetland delineation, soil test pits, hydraulic modeling, plans, specifications, cost estimate, permitting support, construction quality assurance guidance, and an operation and maintenance plan.
Upper Pike Stream Crossing, NRCS NH
D&K, through an on-call contract for Soil Conservation services, designed a fish friendly and cost-effective, 38-ft-span bridge suitable for logging trucks. The new bridge replaced an undersized 7-ft culvert that was a barrier to fish passage and was contributing to channel instability due to upstream deposition and downstream scour. The design of the bridge abutments consisted of stacked concrete waste blocks set back from the channel to reduce scour potential. Large angular riprap was used to further protect the abutments from scour, but was concealed by native cobbles and boulders. The bridge superstructure consisted of pre-engineered steel framing with timber decking. Total construction cost was less than $50,000 and the entire construction sequence, from removal of the old culvert to final seeding and mulching, was completed in only five days. Project was completed under the Wildlife Habitat Incentives Program (WHIP).
DuBois & King’s water resources and structural engineers provided the following services:
Survey
Wetland delineations
Stream geomorphic assessment
Fish passage evaluation
Natural channel restoration
Hydrologic and hydraulic analysis
Evaluation of alternatives for bridge and culvert design
Evaluation of alignment alternatives using computer simulated truck turning movements
Coordinated abutment design with superstructure manufacturer
Analyzed and designed substructure for internal and external stability
Permitting
Construction documents
Cost estimates
On-site engineering support during construction
Beaver Brook Dam & Crossing, NRCS NH
Under D&K’s on-call contract for Soil Conservation services, the firm performed site investigation, design, and construction inspection services for the rehabilitation design of the Beaver Brook Dam, which required replacement of the principal spillway, outlet structure, and provided for vehicular crossing. The new spillway includes a precast concrete riser and outlet pipe. The new vehicular crossing is a 15-ft-wide, precast box culvert recessed into the streambed. An oversized “halo” style trash-rack was designed in recognition of historic beaver debris problems. The scope of services included: review of site information and NHDES Dam Bureau files, site reconnaissance and field survey, geotechnical investigation and laboratory testing of embankment material overview, wetlands delineation, preparation of supporting documentation for NHDES, Dam Reconstruction and Dredge and Fill Permit applications, a hydrologic study of contributing watersheds and spillway hydraulics, preliminary and final design drawings of improvements to spillway and vehicular crossing, preliminary and final construction cost estimates, bid and construction phase services, and an Operations & Maintenance Plan (O&M Manual). Wetlands in the project area were delineated, GPS’d, and analyzed for potential impacts associated with the project.
Paul Levesque Shallow Water Management for Wildlife, NRCS
Under D&K’s on-call contract with NRCS for Planning, Design, & Implementing Conservation Practices, D&K performed site investigation, design, preparation of plans and specifications, and construction inspection for a shallow water management for wildlife pond. The purpose of the project was to provide open water areas on agricultural fields and moist soil areas to facilitate waterfowl resting and feeding and to provide habitat for reptiles and amphibians and other aquatic species, which serve as important prey species for waterfowl, raptors, herons, and other wildlife.
The planned practice is Shallow Water Management for Wildlife and the facility is a shallow water pond designed in general accordance with Standard 646 Shallow Water Management for Wildlife. The pond has ¼-acre of surface area with a maximum depth of 4-ft and required a total excavation of approximately 1,320-cy. The periphery has a curvilinear outline that blends with the natural topography of the site. The depth of water varies from several inches to a maximum of 4-ft. The pond hydrology is fed by a high ground water table and associated discharge.
D&K’s Certified Wetland Scientist worked closely with the NRCS District Biologist on the project relative to geometry, location, planting plan, and selection of seed mixes and plantings. D&K conducted a site visit; delineated wetlands within the area; reviewed hydrology; conducted a topographic survey; and prepared preliminary and final design plans, technical specifications, and cost estimates. The project was completed under NRCS’ Wildlife Habitat Incentives Program (WHIP).