The Baltimore City Department of Public Works (DPW) is converting open-air drinking water lakes to buried tanks to help preserve the city’s drinking water system and comply with federal Safe Drinking Water Act regulations. Stiver Engineering provided a custom shoring pit with support frame, plans for pipe supports and pipe hangers for large diameter steel pipe. We also provided the review of pipe plugs and the design of thrust restraint steel frames for large diameter pipe plug testing. Stiver Engineering performed bi-monthly slope stability reviews for the tank executions which were 430 ft. diameter and 50 ft. deep. We also provided excavation plans in rock material at critical locations for the installation of the influent pipes and the tank foundations. We reviewed rock borings and provided a trench safety plan. DPW is investing in safer and more secure drinking water with underground tanks.
As part of a major infrastructure project at the Schoharie Reservoir in Gilboa, New York, Stiver Engineering provided a variety of services for a low-level outlet designed to release water downstream into Schoharie Creek to facilitate dam maintenance and emergency response, mitigate flood risk, and enhance downstream habitat for fish and wildlife. The work includes construction of a 9.5-foot diameter micro-tunnel at a depth of 160 feet. Stiver provided designs for the gate shaft as well as analysis of the steel jacking frame for the tunnel machine and steel pipe. We also provided trench safety designs, thrust block designs, steel pipe casing designs, anchor bolt attachment designs, and a structural review of the Herrenknecht tunnel launch seal and pipe break frames, among other services.
Division 1 of this Project consists of, but is not limited to, the following: raw water pump station including passive intake screen, intake line, wetwell, two (2) vertical turbine pumps and space for a third pump, bridge crane, and potassium permanganate feed system; cast-in-place concrete 2.5 MGD pretreatment facilities including two-stage rapid mix, two-stage flocculation, high rate sedimentation using plate settlers, and hoseless sludge collectors; 2.5 MGD (expandable to 5.0 MGD membrane filtration facility including membrane filtration treatment modules, CIP system, neutralization system, onsite hypochlorite generation system, chemical feed systems, control room, lab, restrooms, locker room, offices, break room, finished water pumping facilities (two (2) vertical turbine pumps and space for a third pump); finished water storage consisting of a 75-foot-diameter by 30-foot tall 1.0-MG pre-stressed concrete storage tank; plant control system (PCS) consisting of field mounted instruments and control devices, non-proprietary distributed control system utilizing personal computers (PCs) and programmable logic controllers (PLCs); all related site work, piping, electrical, and any other activities incidental to the completion of this Project. Division 2 of this Project consists of, but is not limited to, approximately 8,975 linear feet of 20-inch ductile iron raw water transmission main from the new Lake Hartwell Raw Water Intake on Durham Road to the existing 20-inch main on South Carolina State Highway 59 near the intersection with Fair Play Boulevard in Fair Play, South Carolina, including all related equipment and appurtenances, connections to existing waterlines and facilities, erosion control, grassing, and any other activities incidental to the completion of this Project. No additional specifications were given.
Stiver Engineering was retained by the contractor to provide structural engineering services for the design of the caisson (raw water pump station). The caisson is 16 ft. diameter by 50 ft. deep. The contractor successfully sunk the caisson in wet sand. Stiver Engineering designed the reinforced concrete caisson to be sunk and sealed underwater. This is a technique that we spent many years learning from working with contractors while sinking caissons in the saturated sandy soils of South Texas.
The purpose of the Luce Bayou Interbasin Transfer Project is to provide additional surface water supplies to end users that utilize water from Lake Houston. Additional surface water supplies will be transferred from the Trinity River to Lake Houston via the Luce Bayou Interbasin Transfer Project to meet the increased demand for surface water. There are currently no conveyance facilities to provide raw Trinity River water to the Northeast Water Purification Plant, which treats water from Lake Houston. The Northeast Water Purification Plant is vital in providing treated surface water to City of Houston customers and previous studies have shown that Lake Houston and Northeast Water Purification Plant cannot meet future demands at their current capacity. Transfer of additional raw water supplies to Lake Houston and future expansion of treatment capacity at the Northeast Water Purification Plant is required to allow for the mandatory conversion from groundwater to surface water. The Luce Bayou Interbasin Transfer Project will provide the additional raw water resources necessary to satisfy these demands. The City of Houston, Texas holds permits to divert raw water at a maximum rate of 775 cubic feet per second (approximately 500 million gallons per day) from the Capers Ridge site to Lake Houston.
The Luce Bayou Interbasin Transfer Project includes the Capers Ridge Pump Station located on the Trinity River in Liberty County, 3 miles of dual 96 inch diameter pipelines, and 23.5 miles of earthen canal system. The pump station will be located on the Trinity River. The pipeline will extend west southwest approximately 3 miles along a geological ridge (Capers Ridge). The pipeline will then outfall into the sedimentation basin at the start of the canal. The canal will outfall into the lower reaches of Luce Bayou, which flows into the northeastern corner of Lake Houston.
Stiver Engineering was retained by the contractor to provide construction consulting through a cofferdam design for the construction of the Capers Ridge Pump Station. Stiver Engineering also provided excavation plans for the installation of the proposed dual 96 inch diameter outlet piping.
Stiver Engineering was retained to provide a contractor in Austin, Texas with a caisson design for the proposed Canyon Lake intake structure. The structure was designed to be 20 feet in diameter and 135 feet deep, and it was constructed by blasting through 135 feet of limestone.
Stiver Engineering provided structural design by designing for the wall and bottom slab of the caisson, which consisted of rock bolts, wire mesh, and shotcrete. We also provided a reinforced concrete design for the bottom slab.