S&ME was the prime consultant for assessing and remediating site contamination. In planning site development, the owner, the North Carolina Department of Cultural Resources (NCDCR), retained the architectural services of BJAC. In turn, BJAC and NCDCR relied on S&ME to guide the project through a maze of state and national environmental regulations, thus paving the way for development of a property fraught with hazardous constituents, including metals, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and asbestos.

Role of Other Consultants

No other consulting firms were involved in assessment and remediation.

Original or Innovative Application of New or Existing Techniques

The former Barbour Boat Works (BBW) occupies a 5.8-acre site along the banks of the Trent River in New Bern, North Carolina. The property once consisted of wetlands and shallow waters of the Trent River, which over years was filled in to create a land mass by using fill soils and residue, saw dust, and wastes from past industrial activities. The BBW site was used primarily as an industrial and commercial sawmill and later, for boat production, sales, and a commercial marine maintenance yard.

The land was donated to NCDCR by the heirs of the land owner. NCDCR was unaware of the magnitude of soil and groundwater contamination as well as the complexity of environmental regulatory requirements bestowed upon them.

Challenges faced by S&ME, the architect, and the owner included 1) a complexity of regulatory oversight from both state and federal agencies regarding site contamination and, 2) obtaining the necessary approvals to proceed with construction, including a Coastal Area Management Act (CAMA) Major Permit for remediation next to the river.

The sources and types of environmental contamination, and the limited funds available to ‘fix’ the site before developing a Silver LEED (a green public facility) presented S&ME with many challenges, for example the removal of subsurface and underwater structures embedded in contaminated soil and sediments. We also needed to remove contaminated soil and landfill debris so that artificially-made wetlands could be constructed along the riverfront, and for protection for short-term exposure of construction workers, the public and the ecosystem of the Trent River.

The regulatory agencies included the NC Coastal Zone Management, the NC Division of Water Quality (DWQ), The NC Division of Waste Management (DWM), and the NC Fish and Wildlife Commission. S&ME also had to address concerns from federal agencies such as the US Army Corps of Engineers (USACE) and USEPA Region 4. In all some eight agencies were involved. Integrating the cooperation of each of these regulatory agencies to achieve consensus on a wide array of remedial actions, demolition, and construction was paramount to the project’s success.

Three primary stages of the project were:

1. Preparing the site for demolition

2. Identifying contamination in the soil groundwater and sediments

3. Devising a remediation plan to protect human health and the environment while keeping costs down

In stage one, S&ME assessed and designed removal of asbestos containing materials in 15 dilapidated structures and specified the removal of PCB transformers scattered throughout the property. We completed each task under budget. Once these materials were removed, demolition of aboveground structures took place, clearing the first hurdle for development.

In the second stage S&ME identified areas of concern for contamination. We made a detailed assessment of soil, groundwater and Trent River sediments. S&ME was confronted with a massive array of soil contamination volatile organic compounds (VOCs), PAHs, pesticides, PCBs, metals and hexivalent chrome throughout much of the property. Shallow groundwater was contaminated with PAHs and hazardous metals exceeding state remediation standards. River sediments were also polluted with PAHs, arsenic and copper.

In stage three, S&ME evaluated several alternatives before devising a program that remediated hot spots of soil contamination by removing smaller areas or capping larger areas with a geosynthetic clay layer. However, contaminated groundwater and sediments posed a much larger cost problem – on the order of to $8 to $12 million. The project may have been derailed for years if such monies were needed to satisfy the State’s Inactive Hazardous Sites Branch (IHSB) requirements.

S&ME had to find alternatives. To gain better assurances for alternative remedial solutions for sediments, S&ME recommended an additional assessment of the river and an assessment of the risk to the benthic (lowest level ecological region of a body of water) ecosystem not only at the BBW site, but the adjacent upstream, downstream and across stream. Our findings concluded

PAHs and metals were present in sediments throughout the area and were not concentrated at just the BBW site. Moreover, the benthic organism community was more diverse (i.e., healthier) adjacent to the site than in the other areas. S&ME concluded, with consensus from the regulatory community to leave the river sediments alone, because the metals were bound to sediment (i.e., unavailable for biotic uptake), and the benthic community would suffer adverse effects from active remediation (i.e., dredging). S&ME’s innovative approach, using an ecological assessment and risk evaluation, saved the project $3.25 million.

Groundwater remediation also threatened the project’s budget due to costs. Stage three, included an additional six month hydrogeological study gathering data at unprecedented detail on groundwater potentiometry and identifying hydraulic influences of the river’s tide changes and rainfall. S&ME’s goal was to determine if groundwater will transport contaminants to the river, potentially exposing the public and the Trent River ecosystem to hazardous metals and PAHs.

S&ME installed 15 monitor wells and a stream gauge fitted with pressure transducers. Over six months, groundwater elevation data was gathered once every 15 minutes in each well and at the stream gauge generating approximately 17,900± data points per well for a total of over 286,400

data points. These were evaluated statistically to evaluate the cause effect relationship of tide changes in the river to groundwater flow potential with exceptional detail. S&ME also gathered hourly rainfall data from a weather station to statistically evaluate the influence of rainwater infiltration on groundwater flow potential.

With this high-resolution dataset, S&ME identified that the river’s water level is the predominant influence on the on-site groundwater levels with minor influences from precipitation. The relationship between the Trent River water level and on-site groundwater gradients showed little overall movement of groundwater with accompanying migration of contaminants of concern (COCs) across the site. Site groundwater gradients are consistently low but are apparently variable as to direction. The gradients rapidly diminish and even reverse as a reflection of changes in the river water level. Although there may be a minor groundwater discharge into the river, most of the movement appears to be confined to short distances in circuitous patterns.

S&ME concluded that COCs are relatively immobile, and the COCs dissolved in the groundwater are not likely to significantly seep to the river. Rather, the transport of dissolved COCs is likely to cycle in concert with a slight back-and-forth movement of site groundwater. Monitored Natural Attenuation (MNA) is a viable alternative to active remediation. The MNA alternative saved the project an estimated $1 million to $5 million compared to more typical active groundwater remediation. IHSB accepted our approach, allowing the project to proceed in a timely, cost-effective manner.

Future Value to the Engineering Profession

S&ME incorporated risk assessment and an unprecedented detailed groundwater / surface water hydraulic assessment to devise cost effective remediation enabling a development project to proceed while keeping costs down. S&ME also coupled our engineering evaluation for remediation with insightful use of a benthic study and ecological assessment for a property situated in an environmentally exposed area, the New Bern waterfront.

Future assessment and remediation projects may benefit from high-resolution assessment techniques and risk assessment methods to devise perceptive remediation alternatives.

Social, Economic and Sustainable Design Considerations

The NC History Center is a $60.5 million project. This state development is a Silver Award LEED site that was once an industrial wasteland burdened with hazardous materials, plus soil, groundwater and sediment contamination.

Innovative use of existing technologies and methods enabled the project to proceed without budgetary hindrances. The Grand Opening of the new Tryon Palace facility is planned for October 22 and 23, 2010, opening a wonderful piece of New Bern’s waterfront for the public to safely enjoy for generations to come.

Complexity

The technical complexities of assessing and evaluating contamination in multiple environmental media had complicated, difficult regulatory hurdles to clear. S&ME coordinated the gaining concurrence from state and federal regulatory agencies in a Coastal Zone Management county.

This required an extensive, collaborative effort from all parties involved. Without this cooperation, the project would have suffered longtime delays.

Exceeding Client/Owner Needs

S&ME worked closely with the prime architect BJAC and the owner, Tryon Palace / NCDCR to find intricate remedial solutions that would not financially hinder the project’s timeline. To meet client/owner needs, S&ME complied with rigorous project deadlines, imposed by grant restrictions for creation of the manmade wetlands, and with contractor-imposed construction schedules. An NCDCR Capital Projects Office engineer said, “S&ME, Inc performed exceptionally well in their long-term involvement…at the former Barbour Boatworks site, from early clean-up efforts to the expertise required to make the fine museum opening in October 2010 a reality.” The end result…Tryon Palace’s new waterfront super fun place for all to enjoy.

Broker Breeze
Wilmington, NC

Recently, WRAR selected S&ME, Inc. to provide the Special Inspections and Testing Services on the new WRAR building on Sir Tyler Drive.

S&ME also offers free consultations to REALTORS® with questions regarding particular sites or a project. Typical questions involve environmental issues such as: CAMA Permits, Wetlands, Septic Tank Permits, Underground Storage Tanks, Contaminated Soils, etc.

They can advise you on the most practical and cost effective solutions. Speaking with one of their Environmental Consultants or Engineers can many times save you &/or your client a lot of time and money. S&ME encourages you to call them about issues you’re having regarding : (1) Environmental or Natural Resources Issues (2) Soil Science/Geotechnical Engineering (3) Construction Testing QA/QC or Special Inspections Services.

For more information on S&ME, Inc., please visit: http://www.smeinc.com.

Brasier has headed the program committee and served as a Board liaison to the Sponsorship committee.  She has been a member of CREW for more than eight years.

She also serves on the planning committee for the June 2011 conference of the North Carolina Economic Developers Association (NCEDA), which will be held in Asheville, NC.

Also, a private contractor S&ME, hired by the Division of Waste Management, is expected to begin its own $38,962 assessment on the site beginning in the first week of October and running no later than Dec. 20. The assessment is to include groundwater sampling, vapor sampling and removal of electric capacitors.

S&ME also provided construction materials testing and special inspection services for this project. These services included field density testing on the backfill placed for the below-grade cast-in-place concrete walls; reinforcing steel inspections for the foundations, walls, and slabs; and full-time observations during concrete placement, structural steel and precast concrete connection evaluations, and sprayed-on-fireproofing evaluations.

S&ME provided drilled shaft construction inspection services including load capacity evaluations (in the field). Providing our services in this manner allowed many of the drilled shafts to be constructed to a shallower depth that ultimately led to about $100,000 in savings to the owner. In addition, S&ME provided reinforcing steel (rebar) inspections that allowed the contractor to proceed with drilled shaft concrete placements without having to wait on the local building inspector. This was discussed and agreed upon with the inspector on the first day of the project- the inspector was well aware of S&ME’s capabilities and thoroughness of our inspections. We also had in-progress field reports available for the inspectors review when he did visit the site, and he was pleased. S&ME also provided rebar inspections for other structural concrete areas when the structural engineer’s representative could not be present. S&ME also provided proof load observations for a tie-back wall retaining wall and concrete testing of shotcrete that covered the wall; fill and backfill testing; asphalt pavement testing; monitoring utility construction during road crossings/closings at night and during weekends; structural precast plant inspections and field welding inspections of precast concrete panels.

S&ME’s services for this project included testing and observation on the soils, concrete, masonry, structural and reinforcing steel, and asphalt.

S&ME’s engineering technicians performed proofrolling of subgrade soils in structural and pavement areas, soil density testing to confirm required compaction, visual soil classifications to confirm suitability of fill material, laboratory proctor tests for maximum dry density, optimum moisture content.

S&ME’s engineering technicians performed the following services for the masonry construction: monitored the placement of reinforcement, monitored the placement of grout in the cells, fabricated masonry grout prisms, monitored temperature and batch times, and performed compressive strength testing of grout prisms.

S&ME performed the following services on the structural steel: observation and visual weld inspections to verify torque on bolted connections and observation of reinforcing steel.

S&ME’s engineering technicians performed the following activities for the concrete construction: monitored the placement of concrete, performed slump testing, air content testing, unit weight testing, fabricated concrete cylinders, monitored concrete temperature and batch times, and compressive strength testing of concrete cylinders

Construction of the two parking decks was underway when S&ME was asked to perform Special Inspections and construction materials testing for the project. Another independent testing firm had worked through construction of the drilled piers foundation phase of the project. S&ME took over the testing and Special Inspections work at the time the elevated slab placements began. Our services covered the remainder of the elevated post-tension concrete slabs, columns, pour strips, structural steel, and exterior façade for the parking deck structures. In addition, we managed the resolution of outstanding discrepancies observed and documented by the other independent testing firm related to the parking deck elevated floor slabs placed prior to our work on the project.

Special Inspections were performed in accordance with Chapter 17 of the International Building Code to determine compliance with the contract drawings and specifications. Specific responsibilities included reviewing specifications and drawings, determining required inspections and results, reviewing qualifications of assigned project staff, reviewing the S&ME Special Inspection Electronic Reporting Database, and resolution of discrepancies identified.

The design plan included onsite and offsite mitigation areas. Approximately 1,320 feet of perennial stream was created on site. Shear stresses were calculated for the design channel and tested for compatibility with the shale bed material left by the site grading conditions. Approximately 525 feet of perennial channel, 850 feet of intermittent channel, and 6.7 acres of wetland were created at the offsite mitigation area. Due to the TVA  power lines traversing overhead the planting plan was developed from desirable native herbaceous plants that would be planted in the constructed low marsh areas under the power lines, since larger woody species would be problematic.

The onsite mitigation area was completed in the spring of 2005 and the offsite mitigation area was completed in the spring of 2006. S&ME is currently providing the annual monitoring for both mitigation sites. To date, both mitigation sites are meeting their design goals.

S&ME performed extensive subsurface explorations and comprehensive geotechnical analyses necessary to 1) estimate settlements due to the 400-kip to 700-kip structural loads and the weight of up to 12 ft of new fill, 2) evaluate the site soils for the 2000 International Building Code design earthquake, 3) estimate the risks of seismically-generated liquefaction, 4) provide foundation design alternatives, 5) address site preparation and earthwork issues, and 6) provide parameters for the design of below-grade walls.

S&ME provided an innovative foundation design for the hotel that included ground improvement in the building area to densify the site soils and significantly improve conditions for the consideration of shallow foundations. The ground modification method recommended and implemented was vibro-replacement, or the installation of sub-surface stone columns. By performing vibro-replacement at this site, the site soils were densified making the settlement due to the building loads an acceptable level and significantly reducing risks to the enormous hotel and conference center complex during an earthquake. The soils were pre-loaded with the planned fill and settlements were monitored. After sufficient settlement due to the weight of the fill occurred, then building construction could begin. S&ME designed a shallow foundation system for the hotel structures, as opposed to a costly deep foundation system. The use of vibro-replacement and shallow foundations instead of deep foundations is estimated to have provided a positive economic impact for the owner exceeding $1 million.