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300 Block 21st Street Sewer Design & Construction Phase Services
As part of the redevelopment of a property located in the City of Richmond, the existing combined sewer segment running through the development was abandoned in place by the developer. This resulted in abandonment of the granite box sewer upstream on the developer’s property. The City of Richmond requested that a diversion of the upstream flow be created by installing a new 24-inch pipe using jack and bore along an alley, connection of the new alignment into an existing 12-inch pipe by installing a new manhole, and replacement of the existing 12-inch pipe with a new 24-inch pipe using open cut. The project also included installation of a temporary bypass pumping system to divert upstream flows until the construction was complete.
ECE's tasks included--
In the Design Phase:
Preparing bid plans, specifications, and engineer’s estimate for the project
Performing hydraulic evaluation for the new pipes and preparing a memo which included bases of design for the new pipes
Conducting utility survey to include topographic, sub-utility, drainage and sanitary, and right-of-way survey
Conducting geotechnical investigations along the proposed new pipe alignment
Conducting dye-testing to verify lateral connections to the granite box sewer and upstream sewers
Providing bid assistance to the city, which included attending pre-bid meeting with the city and procurement, and contractor’s bid review and evaluation
In the Construction Phase:
Contractor’s submittal review for compliance with contract documents
Review and evaluation of contractor’s request for clarifications (RFCs) and providing written responses in accordance with contract requirements
Attending construction progress meetings and perform part-time inspections
Preparing record drawings
Baltimore City Urgent Needs
The City of Baltimore’s Sanitary Discharges of Unknown Origin Program is to identify, investigate and eliminate sanitary discharges in the city’s storm drain system. This program was started to comply with the EPA Consent Decree provisions.
A field crew tests storm drains at various locations within the city and identifies locations which test positive for the presence of ammonia (an indicator for sewage) in the water. Once a location is identified, ECE is tasked with investigating the area to identify the source and device solutions to eliminate the discharge.
During the investigation, ECE performs document research, coordinates CCTV and dye testing activities, performs CCTV video reviews, identifies sewer segments for lining, assists in drafting letters to the HCD (housing and community development) on behalf of the Wastewater engineering division is case of a plumbing code violation etc.
Brewery Byproduct Processing Facility
Environ-Civil Engineering, Ltd. (ECE) is sub-consulting for the Brewery Byproduct Processing Facility. The project involved designing a facility to accept, store and pump high strength brewery waste to various processes throughout the Wastewater Treatment Plant (WWTP). A Preliminary Engineering Report (PER) was developed to identify potential alternatives and to estimate the cost and benefits of the project.
The design included an unloading station with a bypass drain pipe. A 0.75 million gallons (MG) sludge storage tank was repurposed to be partitioned with a new concrete wall to create a -0.15 MG storage facility.
Mixers were sized and designed to be installed in the new storage tank to prevent settling. Progressive cavity pumps were sized and designed to pump the brewery byproduct waste to several final discharge locations: fermenter tank, digestion tanks or gravity thickening tanks. A 2,000 linear feet (LF) discharge pipe was designed to be routed through the existing tunnels to discharge to these locations.
City Lock River Crossing Inlet and Junction Chamber Improvements & Goodes Creek Gate Structure
Richmond's wastewater treatment plant (WWTP) serves approximately 58,000 customers in the city and is the largest of its kind in Virginia. Located along the south bank of the James River, the plant can treat up to 70 million gallons a day of sanitary sewage and stormwater before returning it to the river. The wastewater utility also operates and maintains 1,500 miles of sanitary sewer, pumping stations, 38 miles of intersecting sewer lines, and the Shockoe Retention Basin, a 44-million gallon stormwater reservoir used during heavy rains. The WWTP treats wastewater flows arriving from both the north and south sides of the James River, traveling beneath the river in some instances. The Twin 66s are a pair of 66-inch diameter concrete interceptors, traveling from Chapel Island on the north bank of the James River to the south bank of the James River at the WWTP. The Twin 66s have a large concrete Inlet Chamber, which collects flow before discharging into the Twin 66’s, and a large concrete Junction Chamber, which received flow from the Twin 66’s. The City Lock Project is for the structural additions to the existing Inlet and Junction Chambers. It also includes a new buried concrete gate structure and 72-inch sluice gate on the Lower Goodes Creek Interceptor along Brander Street.
The structural addition will provide access from grade to the Twin 66-inch siphons and the 96-inch Shockoe Interceptor for cleaning and maintenance. The project also includes design for a permanent all-weather access road from the Shockoe Retention Basin on Chapel Island to the location of the Inlet Structure near Richmond City Lock. The City of Richmond has requested that bid documents be compiled for the structure modifications and the new gate structure, including plans, specifications, and a project book for bidding general contractors. ECE was sub-contracted on as a sub-consultant whose tasks included design, drafting layout, sub consultant coordination, survey, geotechnical exploration and recommendations, field research, client meetings, and general project administration.
Conditions Assessment of Aerial Crossing Assets
Virginia Beach, VA
As a subcontractor, ECE conducted visual inspections and condition assessments of the City of Virginia Beach DPU’s 54 active water, sewer, and sewage force mains that cross over water bodies (aerial crossings). ECE completed digital forms presenting both the general characteristics of the crossings and the observed facility conditions along with recommendations. ECE’s project manager assisted with field efforts and co-authored the assessment report which documented the condition assessment criteria and results. This report included a summary of the field and desktop assessment methodologies, findings, remediation prioritization, recommendations, and feasibility level cost estimates for the recommended follow-up actions and capital improvements.
Field inspections involved visual inspections on foot where crossings are visible from land, and from boats where crossings are hung under roadway bridges spanning the waterways. Condition observations were recorded for piping, support structure, and general location-specific issues potentially affecting the crossing itself or access for remediation. Based on observations, field conditions, and/or record information, some crossings were identified for follow-up actions to further evaluate condition or criticality. Examples include non-destructive testing to assess wall thickness on older pipelines and desktop reviews of piping network to further assess risks by determining service bypass options if crossings were not available. Physical condition for each of the major components was rated based on a scale of 1 (excellent condition) to 5 (very poor condition). Desktop service-level criticality and risk assessments were also applied to address both service-specific and location-specific conditions for each crossing to develop a relative prioritization for crossing remediation. Criticality rating of 1 (low) to 3 (high) was assessed for each crossing based in part on proximity to critical users such as hospitals, schools, and resort/tourism areas. Other factors for criticality included pipe size and relative traffic ratings for the associated roadway. Relative risk was assessed by multiplying the physical condition rating by the criticality rating to provide a weighted risk value for each crossing and establish the prioritization. ECE’s efforts on this project were successfully completed within budget and schedule constraints. Added value was provided by applying forethought regarding endues of the final report documentation and preparing the final report as a living document for city operations personnel.
Baltimore County Consent Decree
Environ-Civil Engineering (ECE) is currently working on a project for the Baltimore County Department of Public Works (DPW). Consent Decree is a project proceeding by Baltimore County lodged with the United States Department of Justice (DOJ), the Environmental Protection Agency (EPA), Maryland Department of the Environment (MDE) about eliminating the current and historical sanitary sewer overflow (SSO) occurrence in 23 priority and non-priority Baltimore County sewersheds.
The Engineer assigned to this project responsibilities include: updating regular data, tracking communication between the county, and regulators, preparing a monthly report to the county, and annual/quarterly reports for review by EPA and MDE. Furthermore, he conducts overflow event investigations for DPW Bureau of Utilities of root cause analysis and preventative method recommendations.
The Project Manager assigned to this project provide a variety of different tasks, from managing the crew members to assisting in the development of the project. She manages the manhole inspection crew and manages the manhole media data for the end client. She also assigns the crew their work schedules, tracks their work for inconsistencies, and makes sure the equipment is in proper working condition. In addition, the Project Manager also manages their weekly data reports, Quality Assurance (QA)/Quality Control (QC) using the Manhole Assessment Certification Program (MACP) inspections for completeness and correctness, sending weekly completed work to the county. She collaborates with the client regarding assignments and responding and coming up with solutions to their inquiries.
ECE’s Crew Leader responsibilities include: locating and inspecting sewer manholes with a High-Density camera. He also files and logs progress reports of findings to the National Association of Sewer Service Companies (NASSCO) database. The Crew Leader also views the mapping of the Sewer Lines/Tunnels shoot photos for inspections to report in the Database logs.
The Field Technician tasks for this project are similar to the Crew Leader, he also responsible for the inspection of manholes throughout Baltimore County. He documents the defects and other structural issues utilizing a pole camera along with a “Toughbook” with NASSCO Pipeline Assessment Certification Program (PACP) certified software. Finally, he provides the guidance and supervision to other crew members.
DC Water Local Sewers Rehabilitation G100
The District of Columbia Water and Sewer Authority (DC Water) recently identified necessary improvements to its sewer collection system. They adopted the Sewer System Facilities Plan (Facilities Plan) produced by Engineering Program Management Consultant 3A (EPMC-3A) in June 2009. Rehabilitation projects for the sewer system were identified as Capital Improvement Program (CIP) projects in the Facilities Plan. The goal of the project is to address structural defects found through Closed Captioned TV (CCTV) inspections completed during the CIP development. The preliminary construction cost estimation is $13.0 million, which is expected to change per future revisions to the project plan.
ECE's tasks included:
Reviewed all available manhole inspection reports for manholes in the Northwest UPI Sewershed All inspection reports were reviewed for accuracy of NASSCO MACP coding to determine the appropriate rehabilitation method.
Performed field reconnaissance to identify and document potential neighborhood and traffic disruptions, verify existing conditions including photographs, and identify and document locations and requirements for contractor storage during construction.
Prepared cost estimates for the sewer and manhole rehabilitation based on a preliminary quantity take-off and estimated construction unit prices using a database of rehabilitation projects metropolitan area.
Prepared construction work plans to show all intended sewer rehabilitation work in the Northwest UPI Sewershed.
Prepared erosion and sediment control plans and details for use during the construction phase in the Northwest UPI Sewershed.
Completed a neighborhood site investigation to observe existing document potential vehicle and pedestrian traffic conflicts relative to proposed construction work limits.
All results and documents were provided in a technical report to DC Water.
ENR Facilities at Patapsco Wastewater Treatment Plant
ECE served as a sub-consultant on the construction management team for the Patapsco Wastewater Treatment Plant. Under this on-call contract, ECE provided both civil and mechanical inspection support.
ECE performed the inspections for subgrade preparations, installation of HPDE liners, and the installation of rebar mating to ensure that it was installed as per contract drawings and placement of concrete. The project included overseeing the installation of equipment, such as backwash pumps, main feeding pumps, backwash blowers, polymer units, polymer blending units, polymer tanks, thickened sludge tanks, thickened sludge pumps, aeration nozzles and drop legs for the DNF filters and mud wells. The Dissolved Air Floatation Thickening (DAFT) units, air compressors, skimmer units and associated piping for each unit. ECE observed and verified the installation of media for each filter in DNF and cell in BAF. ECE also observed the testing of all associated piping systems and testing for each unit, and weekly/monthly maintenance of each unit as performed by the contractor as per the manufacturer’s recommendations and owner’s manuals.
ECE reviewed all of the contract documents, maintained job site as-built records, field correspondence and memos, punch list maintenance, safety compliance assurance, field inspection, daily reports, maintenance logs, quantity takeoff, material logs, and delivery tickets, and attended all progress meetings. Using the construction drawings and specifications, ECE ensured that the construction contractor and trade workers adhered to the technical requirements of the contract documents.
The Hampton Gardens area is located from Greenway Lane to Oak Lane between Grove Avenue and Harlan Circle. The scope of the project includes sewer rehabilitation work to an abandoned 1,080 linear feet (LF) existing and 1 existing manhole in easements through homeowners’ yards and in the street, along with a new gravity sewer main and manholes. The following is a summary of the tasks performed in the project:
Environ-Civil Engineering (ECE) reviewed closed-circuit TV (CCTV) inspection videos of sewer line segments provided by the City of Richmond to make a final determination of the repair needs. ECE engineers identified and investigated the potential cross connections using CCTV inspection and dye testing. The engineers reviewed CCTV inspection videos of storm sewer main lines that run adjacent to sanitary sewer line segments to document the condition of the storm sewer mains. ECE’s engineers performed site visits to identify utilities and potential utility conflicts; summarized the observations made during the field investigation in a letter report as a supplement to the Hampton Gardens Report. The engineers prepared work assignments for rehabilitation work using the annual services cured-in-place pipe (CIPP) and open excavation contracts to correct the potential sources of cross connections being investigated. ECE’s engineers provided work assignment drawings and cost estimate for the open trench pipe replacement of line segments. The engineers designed the replacement of the existing sanitary sewer line with a new pipe to improve the pipeline’s alignment as recommended by the report. A field survey was performed to delineate property lines, identify potential utility conflicts and identify topographic features along the proposed sewer routes. ECE engineers observed the installation of approximately 1,100 LF of8-inch diameter sewer in a new alignment in Roslyn Road and Harlan Circle. The engineers also observed the installation of a total of 8 new manholes, 6 manholes along the new alignment. ECE engineers observed site and street restoration to include landscaping and traffic control; prepared field survey maps to show existing sanitary, storm, other utilities, and easements to property lines from the City’s GIS files and contours along the proposed sewer routes. ECE also prepared the cost estimates for project and provided construction phase services.
Hubner Building Waterproofing Design
Environ-Civil Engineering, (ECE) was contracted by the Maryland Department of General Services (MDGS) to provide engineering design and construction management services to stop water from infiltrating into the Hubner building during storm events. The services were provided in 5 phases: Phase I - Schematic/Conceptual Design; Phase II – Design Development; Phase III – Construction Document; Phase IV – Bidding Phase; and Phase V – Construction Phase. The description of the work performed is as follows:
Phase I - Schematic/Conceptual Design: Site visits were conducted to evaluate site conditions and obtain background information for input in the conceptual design process. All the existing as-built drawings for the site were reviewed and evaluated. Data gaps were identified and filled prior to the start of the conceptual design. Additional field tests were performed to identify infiltration routes to the inside of the building.
Phase II – Design Development: ECE prepared drawings and documents that comprised of Schematic Design Phase, including elevations and cross sections. A site development plan that showed the existing project structures, utilities, roads, sidewalks, grades, parking facility and pertinent structures in the vicinity of the project site was prepared by ECE. All calculations, proposed alterations and/or work were shown on the drawings.
Phase III – Construction Document: ECE prepared the design and construction documents which were produced and submitted at 50%, 90% and the 100% final phase to MDGS for review and approval. ECE attended two meetings during the design and construction phases of the project to discuss progress and schedule. An estimate of probable construction costs of the project and construction schedule were prepared and submitted to MDGS.
Phase IV – Bidding Phase: ECE attended a pre-bid meeting to provide clarifications on questions submitted that the general contractor asked on the construction document. ECE looked at the bid submitted to MDGS to analyze and compare with probable construction costs prepared by ECE.
Phase V – Construction Phase: The construction phase services provided by ECE included conducting pre-construction meetings, review of contractor submittals, review of construction schedules, review of design scope changes, responding to RFI’s and RFP’s, scheduling and attending progress meetings and site visits to discuss and resolve problems, preparation of construction progress reports and meeting minutes, review of construction contract change orders, review cost proposals and assisting the agency in negotiations, review of contractor payment requests, resolution of on-site issues and conflicts that were identified during construction and preparing a list of defects and omissions related to the work performed for the contractor. ECE prepared the punch list and performed the final work through to close out project.
Lakeside to Strawberry Hill SPS Flow Equalization Pipeline Project
Henrico County currently offers sanitary sewer service to approximately 91,600 customers and treats over 14,000 MG per year. The Flow Equalization Pipeline Project has been implemented in response to a Consent Decree for increased storage capacity prior to the Strawberry Hill pumping station and to provide redundancy and flexibility for maintenance and repair.
This project will provide 6 MG of additional sanitary sewer storage during wet weather conditions. The designed phase finished and construction phase began in fall of 2012. ECE is supporting the County of Henrico as a sub-consultant performing pipe calculation for a 114-inch diameter FRP (fiberglass reinforced pipe) interceptor to run parallel to an existing 72-inch interceptor in the southeastern portion of the County. In addition to pipe calculations for buoyancy control, ECE provided design for various concrete junction chambers; overall project management support; assistance with project coordination; and drafting support. Now that the construction phase has begun, ECE is providing construction inspection support, submittal reviews after bid and award, drafting assistance for record drawings, and general project close-out.
Little Patuxent Water Reclamation Plant Additions #6 & 7
Environ-Civil Engineering (ECE) was contracted to assist the Howard County Department of Public Works (DPW) in providing construction inspection services during extension #7 of the Little Patuxent Water Reclamation Plant located in Savage, Maryland. The project was implemented in two phases, Phase 1, consisted of the construction of anaerobic tanks. The work performed was related to the inspection of the anaerobic tanks constructed for the treatment system of waste received at the plant from a nearby Dairy company.
The components of second phase of the construction included:
- Replacement of the existing raw wastewater screens and conveyors
- Upgraded the facility to meet Code requirements; upgraded primary clarifier #1 and modified the yard piping.
- Construction of one new North process reactor similar to the existing units
- Modification of the existing East/West biological process reactors and constructing a new splitter box.
- Modification of the existing North biological process reactors.
- Construction of one new North final clarifier (clarifier 13).
- Replacement of the RAS and WAS pumps, piping and appurtenances in the existing North, East and West pipe galleries.
- Upgraded the New Auxiliary North pipe gallery with new RAS and WAS pumps, piping, and appurtenances.
- A new East/West Blower Building
- Replacement of two existing blowers in the North Blower building
- Rehabilitated the final existing clarifiers 2 through 5 where we replaced the sludge and scum collection mechanisms and replaced the in-board effluent launders.
- Construction of the new Denitrification filter complex including influent pumping station, clear well, mud well and the ultraviolet (UV) Disinfection facility.
Construction of the new Methanol storage and feeding system. Upgraded post aeration system with the membrane diffuser system and centrifugal blowers; new effluent flow metering vault. In addition, worked on the Alum feed upgrades; Hypochlorite feeding upgrades; upgraded one new high solids decanter centrifuge added to the dewatering building. ECE upgraded and expanded odor collection and treatment facilities for the dewatering and lime stabilization areas; miscellaneous piping modifications; miscellaneous electrical modifications and upgrades. The services that ECE provided included, but were not limited to, the following: participation in the weekly and monthly construction progress meetings; assisted the client with the preparation progress reports during construction; maintained effective public and political relations. ECE also assisted the client in the technical requirements of the contract documents, and provided the construction inspection services.
Rehabilitation Plan, Design, and Construction Phase Sewer Collection System (Sewershed Area 7-5 and 5-7)
This project consists of sewer rehabilitation projects in sewershed areas 5-7 and 7-5 in the City of Richmond, Virginia. Sewershed area 5-7 is bounded by Shadwell Road, Westmoreland Street, Cary Street and Hanover Avenue. Closed Circuit TV (CCTV) videos of approximately 16,200 LF of sanitary sewers and manholes were reviewed in this sewershed. Sewershed area 7-5 is bounded by Henrico Turnpike, Meadow Bridge Road, Gladstone Avenue and Brookland Park Boulevard. Closed Circuit TV (CCTV) videos of approximately 22,450 LF of sanitary sewers and manholes were reviewed in this sewershed. Excel spreadsheets with sewer line defect coding were prepared. Field inspections were performed to identify feasible alternatives for rehabilitation of sanitary sewers in these sewersheds. Suitable rehabilitation alternatives were recommended to the City along with cost estimates and detail plans for rehabilitation. ASTM F1216-07b standards were used to determine the Cured-In-Place Pipe (CIPP) lining thickness.
Richmond Riverfront Stormwater Watershed Master Plan
The City of Richmond wants to develop a Stormwater Master Plan for the entire city to identify and prioritize recommended capital improvement projects for mitigating flooding, strengthen or improve the stormwater infrastructure, prevent stream bank erosion and improve stream water quality. The City has identified and prioritized watersheds within the City and Riverfront Watershed is one of them.
The project is currently on-going. ECE’s responsibilities include:
- Delineating the watershed and subbasins using GIS
- Fieldwork after a storm event to observe the various types of stormwater infrastructure (inlets, culverts, ditches, etc.) within the watershed and identify potential improvements or problem areas.
- Typing up reports in a template as well as putting data into a PowerPoint presentation template to present to the City of Richmond for further evaluation.
Potential projects have been identified and will be presented to the City for its review. The City will then provide comments and the reports will be revised accordingly before action is taken.
Richmond Water Plant System Upgrade Phase II
The City of Richmond’s Water Treatment Plant (WTP) utilizes finished, potable water for many uses within the WTP itself. The existing plant water system continues to have numerous potential cross-connections. Plant water schematics identified many areas where potable (e.g. restrooms, emergency showers and eye washes) and non-potable (e.g. chemical dilution) uses are interconnected in the same piping system for both Plants 1 and 2. This project separated the potable and non-potable uses into two separate water supply systems. The work involved the design of upgrades to the PWS to separate potable uses from non-potable, eliminating cross-connections, and the work also involved the design of installation of water meters and backflow devices on PWS feeds to Plant buildings. The tasks included evaluation of the size/capacity of PWS needs, developed preliminary plan to separate the potable and non-potable PWS, preparation of sizing calculations, review of capacity and condition of existing piping to remain in service where appropriate and sizing new PWS piping. ECE designed the repair and removal of the 6-inch main to Loch Lomand Lane. Contract documents were provided in bid packages to allow the city to issue construction documents to Annual Services Contractors to complete the work in phases. Services during construction include inspection, answering contractor questions, and providing record drawings. ECE prepared record drawings based on mark-ups from each Annual Contractor.
Screenings and Grit Facility PER & Design
Environ-Civil Engineering, Ltd. (ECE) was asked to provide engineering services for the City of Richmond during the project called Screenings and Grit Facility Preliminary Engineering Report (PER).
ECE provided an Engineer, he assisted in composing a PER for the new Screenings and Grit Removal Facility at the Richmond Wastewater Treatment Plant (WWTP).
The project involves design of an improved screening and grit removal facility capable of handling 140 million gallons per day (MGD) during wet weather events. The PER presented several alternatives, required modifications to the existing WWTP and cost estimates for the upgrade.
Construction documents were developed for the new facility were designed along with a new odor control system to serve the facility. Modifications were required to connect the existing 96-inch force main from the Main Piping Station with the new facility. A new diversion chamber was designed to divert the flow from the 96-inch force main to the new facility. The existing diversion chamber was modified to serve as an emergency bypass overflow structure with fixed weirs. A 72-inch pipe was designed to convey the emergency bypass flow and to tie into the system just downstream of the new facility. Multi-rake screens were designed in isolated channels to remove screenings and to discharge to trucks on the ground floor. Vortex grit removal units were sized and designed to remove grit which would be pumped to the top floor, classified and removed. An odor control facility was designed to treat the odorous air from the new facility. The design included biological towers, odor control fans and duct work.
SOD Run WWTP Upgrade
Harford County Department of Public Works obtained Construction Management services to oversee the construction on various capital improvement projects. Environ-Civil Engineering (ECE) was part of the construction management team on the Sod Run WWTP ENR Upgrade project. ECE provided inspection and monitoring services of the general contractor’s daily work activities as well as third party inspectors, for concrete, rebar, and soils inspections for expansion and rehabilitation of plant process reactors and clarifiers.
ECE’s inspector prepared and maintained a daily construction inspection report/log documentation of field activities which included: the status of existing tasks, commencement of new tasks, inventory of major equipment on the site, tests performed, problems and errors in the field, items not conforming to project documents etc.
ECE’s inspector documented and verified site work on a daily basis such as materials, location, dimensions, quality etc. to ensure conformance with the project documents. Additionally, the inspector scheduled and coordinated all quality assurance testing on the site including third party testing. Using Primavera CM-13 software, the inspector reviewed and checked RFI’s and submittals.
ECE’s inspector scheduled third party inspectors for soils inspections and concrete testing. ECE’s Inspector compiled daily report work activity.
Whitcomb Court Sewer Improvement Project
Richmond's wastewater treatment plant (WWTP) serves approximately 58,000 customers in the city and is the largest of its kind in the state of Virginia. The treatment plant is located along the south bank of the James River. The plant can treat up to 70 million gallons a day of sanitary sewage and stormwater before returning it to the river. The wastewater treatment plant also operates and maintains 1,500 miles of sanitary sewer, pumping stations, 38 miles of intersecting sewer lines, and the Shockoe Retention Basin, a 44-million gallon stormwater reservoir which is used during heavy rains.
The Whitcomb Court Sewer Improvement project is a residential gravity sewer replacement project within the City of Richmond. The project includes the abandonment of 1230 linear feet of the existing 12-inch diameter sewer. The removal of the Shockoe Creek Crossing (a portion of aerial sewer which crosses the Shockoe Creek), and the installation of approximately 1775 linear feet of a 12 inch-diameter ductile iron sewer in a new alignment in Sussex Street, from Hospital Street to Carmine Street. The project also includes new manholes and associated tie-ins to existing sewers. The replacement sewer will intercept the existing sewer behind the Richmond redevelopment and housing authority (RRHA) Building on Carmine Street and will run generally south in the existing roadway. The City of Richmond has requested that bid documents be compiled for the new sewer, including plans, specifications, and a project book for bidding by general contractors. The project tasks include design, drafting layout, sub consultant coordination, survey, geotechnical exploration and recommendations, field research, client meetings, and general project administration. Environ-Civil Engineering (ECE) is involved in all aspects of the project and will be providing construction administration services after Award. Currently, ECE is at the 90% design stage and proceeding with final design efforts. The RFQ process by the City Procurement department has been started and is anticipated to be complete by March of 2013. Final Design is anticipated to be completed by April of 2013. Award of Contract and Construction is anticipated for fall of 2013.
WSSC BOA Hydraulic Modeling Study of Sewer Basins
Washington Sanitary suburban Commission (WSSC) complied with a consent decree (CD) that required that a system-wide fully-dynamic sanitary sewer system model be developed. The sewer system models developed under this contract will be applied in subsequent studies to prepare sewer system repair, replacement, and rehabilitation plans.
ECE was subcontracted to develop Dynamic Hydraulic Sewer Models for WSSC using InfoWorks CS software. WSSC provides public water supply and sanitary sewer service to approximately one million residents in Montgomery and Prince George’s Counties comprising the northern, western, and southern suburbs of Washington, DC. The primary objective of the study is to use the model to determine the existing and long-term capacity of the Commission’s wastewater collection system. Rainfall, population projections, manholes, pipes and wastewater pumping station data were analyzed in GIS and the collection system network was modeled using InfoWorks CS software. The model was run to evaluate the future dry weather flow and wet weather flow (for standardized storms). The results of the study were documented in a report submitted to WSSC. ECE performed the following steps to develop the model: Initial Data Assessment, GIS Sewer System Data Processing, and import of Data into the Model. This stage also identified and documented the critical data such as pump station information, flow diversions and standard operating procedures required to perform the modeling. The data imported was verified and validated to identify and remove duplicates, and to identify pipes and manholes with missing data to check the network against available record drawings to correct and/or fill in the missing data. Area estimates were prepared from aerial photographs using GIS tools like Arc MAP. Verification, Validation and Calibration of the Network, Dry Weather Flow Analysis, Simulations of Design Storms, Wet Weather Flow Analysis, and Capacity Analysis as well as a Final Basin Modeling Report was prepared.
Under this BOA, there have been currently 18 task orders that covered areas such as WSSC sewer basin facility plans, capacity reevaluations of wastewater pumping stations and model networks, recalibrations of model networks, modeling support, and analysis for new developments. Four of the eighteen tasks are on-going. Tasks were performed within budget and on-time.