DUNCKLEE & DUNHAM


ENVIRONMENTAL CONSULTANTS

 

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Soil and Ground Water Remedial Systems

 

Dr. Trexler and our senior staff have designed, installed, and operated ground water remediation systems including air sparge systems; pump and treat systems with granular activated carbon, air strippers or ion exchange units; dual-phase extraction methods; injection of oxidants and biological enhancers for in-situ remediation; and natural attenuation.

Duncklee & Dunham has developed corrective action plans using underground injection of chemicals to oxidize VOCs or carbon sources to enhance the biological breakdown of the VOCs.  Chemicals such as steam or base catalyzed sodium persulfate, hydrogen peroxide, Fenton's Reagent, potassium and sodium permanganate, and slow release oxygen compounds are used to oxidize and/or biodegrade the organic compound.  The biological process of anaerobic reductive dechlorination can be enhanced by the addition of carbon sources such as lactate or emulsified vegetable oils.

Mr. Dunham has permitting and is currently managing the remediation of a ground water plume site in Delaware contaminated by methyl tertiary butyl ether (MTBE) and other oxygenates found in gasoline by injecting sodium persulfate and steam.  In Virginia, Mr. Dunham has also designed and permitted an injection program to enhance the indigenous microorganisms and increase their breakdown of dissolved nitrate contamination.

Dr. Trexler has designed and permitted an underground injection program for a North Carolina site using hydrogen peroxide and persulfate to remediate two landfill trenches containing chlorinated VOCs.  The two trenches represent the source area for a 1,000-foot long plume contaminated by PCE, trichloroethene, and the dichloroethenes.  Underground injection is also being used in the contaminated plume to enhance the ongoing reductive dechlorination process.

Mr. Duncklee currently has permitted and is operating:

·        a chemical oxidation process for removing tetrachloroethene (PCE) from ground water using potassium permanganate at a site in Asheboro, North Carolina,

·        a petroleum contaminated site using slow release oxygen compounds in Rowan County, North Carolina,

·        the use of base catalyzed persulfate to remediate a dissolved gasoline ground water plume at a site in Raleigh, North Carolina, and

·        a chemical oxidation process for removing dissolved chloroform using steam catalyzed sodium persulfate for a project in Rabun, Georgia. (see images below)

Mr. Duncklee is a past member of Interstate Technology & Regulatory Council (ITRC), In-Situ Chemical Oxidation (ISCO) team.  The ITRC promotes innovative technologies.  The ISCO team promotes the use of chemical oxidizers and helps establish standard procedures for using chemical oxidizers effectively and safely. 

Our staff has obtained numerous agency approvals for natural attenuation soil and ground water corrective action plans (CAPs).  Natural or passive attenuation CAP rules are most suitable where concentrations of contaminants in ground water are moderate to low or where there is moderate to low exposure to sensitive receptors.  For petroleum UST sites, regulations typically require the removal of free product, and then the State program sets the cleanup level for the dissolved constituents. 

The passive CAP includes the removal of the primary source of the release (a leaking UST for example).  Next, secondary sources such as contaminated soils are controlled by removal, soil vapor extraction, or other methods.  A ground water monitoring well network is installed and sampled to monitor the compounds of concern over time.  The natural processes of biodegradation and natural attenuation will reduce levels of petroleum hydrocarbons as well as chlorinated solvents under the proper conditions.

Mr. Duncklee has obtained EPA Region 4 approval of monitored natural attenuation for a CERCLA regulated site in eastern North Carolina with a chlorinated solvent plume.  Having received EPA and NC DENR approval of the Remedial Design/Remedial Action work plan in early 2000, this project is currently in the monitoring phase.

In North Carolina, the senior staff is involved with sites under the passive CAP regulations.  In 1996, Mr. Duncklee obtained what is believed to have been only the second DENR approval of a 106 (l) CAP for a site with ground water impacted with chlorinated hydrocarbons. 

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Persulfate Injection Pilot Test Chloroform Ground Water Plume

Georgia Site

IMAGES TO THE RIGHT ARE THE CROSS SECTION VIEWS OF THE IMAGES ON THE LEFT.

CLICK ON AN IMAGE FOR A LARGER VIEW.


Pre Injection

                            


Six Months Post Injection

                            


Eighteen Months Post Injection

                            


 

 
 
Latest News at Duncklee & Dunham
 

May  2011

Daphne Jones, Senior Geologist, and Clark Wipfield, Staff Geologist, took the National Association of State Board of Geology (ASBOG) exam on March 4, 2011. These standardized examinations are currently used by 30 states to test for professional geologist (P.G.) licensure. On May 5th, Ms. Jones was notified that she passed the Fundamentals of Geology and Practice of Geology exams, and qualifies to become a P.G. in the state of North Carolina. Mr. Wipfield passed the Fundamentals of Geology exam, and is now a registered Geologist-In-Training for North Carolina.

May  2011

The Brownfields Services Group completed additional Phase II work in Greenville, NC under the City's EPA Brownfields Petroleum Assessment Grant in early May. Work included pulling five hydraulic lifts in a former tire service center. Soil samples were collected under the lifts to determine if the site could be clean closed. Lifts are considered underground storage tanks (USTs) in North Carolina, and work is conducted under the DENR UST Section's guidelines. While lifts could be pulled in order to sample underneath them, over excavation as allowed by the UST Section is considered remediation and cannot be funded under an assessment grant. If the soil samples collected exceed the levels for clean closure, the non-profit foundation that is redeveloping the site as a regional science museum will be responsible for further excavation and sampling to reach closure levels.

February  2011

REC Team staff members met to discuss the findings of a January 2011 technical training session with DENR IHSB REC Program regulators in their Raleigh office. Items of discussion included the addition of phosphorous to the Appendix 1 list in A.7.1.1.3 and new requirements for hexavalent chromium soil testing. In order to stay current and provide a consistent work product, Duncklee & Dunham sends an RSM to each technical event held in the Raleigh DENR office. Upon returning, the results are discussed with other RSMs in the company. The meeting notes are placed in our corporate REC Program Notebook for future reference.

November  2010

Duncklee & Dunham's Brownfields Services Group was awarded the environmental consulting contract with the County of Wayne, North Carolina to implement their hazardous and petroleum EPA Brownfields Assessment Grants ($400,000). The County of Wayne was one of the four North Carolina assessment grants awarded in 2010, along with Charlotte ($400,000), Wilson and Whiteville (both $200,000 grants). All municipalities in the county (e.g. Goldsboro, Mt. Olive, Pikeville) are eligible to use the assessment funds. Our firm is also currently performing similar brownfields assessment activities under EPA grants awarded to Wilson and Greenville, North Carolina.

September 2010

Duncklee & Dunham is pleased to announce Richard A. Kolb, PG has joined our staff as a Senior Geologist/Senior Project Manager.  Rick adds a wealth of expertise in the performance of Phase I Environmental Site Assessments, the design and implementation of all types of soil or groundwater assessments, and in technical writing and review of environmental documents.  His project experience includes the performance or review of over 3,000 Phase I ESA across the US, Puerto Rico, and Mexico.  He has given several Due Diligence presentations to the NC Bar Association and currently serves as the Engineering/Consultant representative on the NC Department of Commerce’s Certified Sites Steering Committee.

August  2010

Rodak Engineering has merged into Duncklee & Dunham.  As a result, Duncklee & Dunham now offers engineering services such as air pollution control design and permitting, stormwater design permitting and monitoring, wastewater system design, point of entry treatment system design and construction, soil and groundwater treatment system design, and environmental compliance auditing and management system support.  For more information about our engineering services, please contact Andy Rodak, PE at andy@dunckleedunham.com .

May 2010

Duncklee & Dunham has been a NC DENR Registered Environmental Consultant (REC) since 1998 and has three DENR approved Registered Site Managers (RSMs) under the REC Program. Duncklee & Dunham RSMs are managing four active REC site projects involving metal, chlorinated solvent, and nutrient contamination in soil and ground water.

February  2010

Dave Duncklee, Tom Dunham, Daphne Jones, Bryson Trexler, and Andy Rodak of Duncklee & Dunham recently attended the 2010 Southeastern In Situ Soil and Groundwater Remediation Conference to maintain our edge in In Situ Chemical Oxidation (ISCO), In Situ Chemical Reduction (ISCR),  and bioaugmentation technologies. The technical presentations, as well as interfacing with other consultants, scientists, and regulators, proved to be valuable.
 


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     Cary, NC 27518

 

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