BIOGRAPHICAL SKETCH

Timothy J. Mayotte, Ph.D., P.E.

Owner/President

General

Tim Mayotte is the President of Mayotte Design & Engineering, P.C. (MD&E) based in Lansing, Michigan.  MD&E is a civil and environmental engineering consultancy that was formed in 2002 and assists commercial and industrial clientele across the US.  MD&E offers a variety of services, specializing in the design and engineering of treatment solutions for wastewater and contaminated environmental media.

Prior to forming MD&E, Dr. Mayotte was a Principal Engineer for MWH Americas specializing in the characterization and remediation of sites impacted with petroleum hydrocarbons and chlorinated solvents.  He holds degrees in geophysics, hydrogeology, and environmental engineering, and is a Registered Professional Engineer and Certified Professional Geologist with over 19 years of experience in environmental consulting.  Dr. Mayotte’s expertise is in fluid flow and transport modeling, and the design/optimization of biological and physicochemical treatment systems. 

As a Principal Engineer with MWH, Dr. Mayotte was responsible for providing technical and management support for special projects, including investigations and remedial actions associated with subsurface impacts by chlorinated organic compounds and dense non-aqueous phase liquids (DNAPLs).  Dr. Mayotte also participated in a multi-disciplinary research program focused on developing biostimulation and bioaugmentation strategies for in-situ remediation of plumes of groundwater contamination consisting of mixtures of chlorinated solvents and heavy metals. The research, conducted in collaboration with investigators from Michigan State University, Stanford University, and the National Science Foundation’s Center for Microbial Ecology, was also focused on improving the understanding of factors affecting microbial kinetics in the subsurface and optimization of numerical models to evaluate the natural attenuation of organic contaminants in aquifer systems.

Prior to joining MWH, Dr. Mayotte founded and was Manager of the Michigan Operations of Golder Associates Inc., which grew to include 30 engineers and scientists within offices in Lansing and Dearborn.  In addition to developing and managing clientele and a diverse range of services during his tenure with Golder, Dr. Mayotte served as a member of the design team for a bioaugmentation process that employs alkaline niche adjustment and controlled inoculation of aquifer materials with Pseudomonas sp. strain KC to rapidly mineralize carbon tetrachloride.  In this role, Dr. Mayotte worked closely with researchers from Michigan State University and the NSF Center for Microbial Ecology to design and execute a succession of bench- and field-scale demonstrations of the technology. 

Dr. Mayotte has also managed successful applications of bioenhancement techniques to cleanup chlorinated solvents, BTEX and PNAHs, including a Superfund Innovative Technology Evaluation (SITE) demonstration of the SVVS® process at the Electro-Voice site in Buchanan, Michigan.  He has conducted numerous presentations and seminars on environmental remediation topics, including serving as an instructor of remediation applications and design for Western Michigan University’s Hydrogeology Field Camp during 1995-97.

During the tenure of his career, Dr. Mayotte has completed projects in: Arizona; California; Connecticut; Illinois; Indiana; Iowa; Massachusetts; Michigan; Mississippi; Nevada; New Jersey; Ohio; Tennessee; Texas; Vermont; West Virginia; Wisconsin; Wyoming; British Columbia; Ontario; Quebec; Brazil; China; the Czech Republic; and Italy.

Wastewater and Storm Water Engineering

Dr. Mayotte experiences have included applications of the following process technologies/unit operations for treatment of industrial wastewater and contaminated groundwater:

• Activated sludge for pharmaceutical wastewater treatment.
  

• Advanced chemical oxidation for groundwater and automotive components manufacturing wastewater containing heavy metals.
  

• Use of aerated lagoons for pharmaceutical wastewater treatment.
  

• Packed-column aeration towers for treatment of chlorinated aliphatic and petroleum hydrocarbons in leachate and groundwater.
  

• Granular activated carbon for treatment of groundwater containing VOCs, BTEX and SVOCs.
  

• Ion exchange for treatment of nickel and chromium impacted plating wastewater.
  

• Emulsion breaking by pH adjustment of coolant-impacted storm and groundwater.
  

• Powdered activated carbon for removal of PCBs in wastewater containing machining oils and coolants.
  

• Equalization of groundwater and wastewater treatment influents.
  

• Coagulation/flocculation/precipitation of aluminum-containing process wastewater and metals-impacted groundwater.
  

• Up-flow anaerobic sludge blanket treatment of pharmaceutical process wastewater.
  

• UV/photolysis of PCB-, VOC- and TMB-impacted groundwater.
  

Through these experiences, Dr. Mayotte has developed numerous hydraulic profiles and volumetric and mass flux balances for groundwater and industrial wastewater treatment systems comprised of multiple unit operations.

Dr. Mayotte also managed a nationwide compliance auditing and infrastructure evaluation program for Ford Motor Company Dealership Development facilities throughout the US.  He and other program participants were routinely required to evaluate drainage and wastewater treatment systems at these facilities, including the inspection of drainage patterns, the appropriateness and conditions of drains, the conditions of subgrade conveyances, and the sizing and operational integrity of subgrade (gravity driven) sand and oil/water separators.  Conveyance inspections typically included: simple water balances; smoke testing; or track-mounted video taping of drainage lines to identify the locations of breaches, clogs or potentially problematic areas.  

In-Situ Remediation Research & Development

Dr. Mayotte’s research and development activities have focused on the following in-situ biological and physicochemical remediation topics and issues:

• Evaluation of geochemical, contaminant transformation, and genetic data collected from soil and groundwater samples to determine the mechanisms and rates of natural attenuation in aquifer systems contaminated with chlorinated solvents.
  

• Laboratory-based enrichment of microbial cultures capable of the complete dechlorination (halorespiration) of PCE and TCE using native microflora extracted from aquifer materials impacted by these chlorinated solvents.
  

• Design of hydraulic delivery strategies to promote even distribution of enrichment cultures into aquifer materials.
  

• Genetic fingerprinting of microbial strains that express dehalogenation activity and key auxiliary members of enrichment cultures.
  

• Geochemical and genetic tracking of the fate and activity of dehalogenators and auxiliary members within impacted aquifer materials following inoculation with dehalogenating enrichment cultures.
  

• Biological and geochemical manipulation of the oxidation-reduction potential of aquifer systems to promote beneficial biotransformation and complexation/fixation processes for the in-situ remediation of certain organic pollutants and toxic metals, respectively.
  

• Extraction of DNA from soil and/or groundwater and polymerase chain reaction (PCR)-based analyses of variable regions of the gene that encodes a portion of ribosomal RNA unique to microbial strains capable of reductively dechlorinating chlorinated solvents by halorespiration.
  

• Detection and quantification of community members that often serve an essential mutualistic role with halorespirors to facilitate dechlorination of compounds such as PCE and TCE.
  

• Non-specific profiling of the community structure within dehalogenating enrichment cultures and correlative examination of the structure of post-inoculation aquifer microbial communities to evaluate the performance of in-situ bioaugmentation strategies.
  

• Bench-scale evaluation and full-scale design of in-situ redox manipulation (chemical) strategies to remediate hexavalent chromium (Cr6+) in unsaturated soils and oxidized groundwater.
  

Transport and Fate of Heavy Metals

Throughout his career, Dr. Mayotte has provided peer and expert evaluation of hydrodynamic and geochemical data to elucidate the fate and transport of heavy metals in a variety of soil types and conditions.  These efforts included integrating solid- and liquid-phase physicochemical measurements such as soil mineralogy, aqueous redox chemistry, organic content, alkalinity and pH to develop technically justifiable conclusions regarding the speciation and mobility of metals such as arsenic, barium, chromium, lead and nickel.  These assessments involved evaluating the transport of lead impacts associated with:

• The release of tetraalkyllead and related organometallic lead anti-knock additives in gasoline;
  

• Lead-charged leachate from buried paint sludges;
  

• Lead oxides and sulfates from smelting and foundry activities; and
  

• Leakage of discarded lead/acid batteries.
  

Technical input included recommendation of analytical methodologies to determine the mass fractions of lead and other metals: 1) surface-bound or adsorbed to hydroxides and carbonates; 2) occluded or precipitated as salts or oxides; 3) complexed with organic material; and 4) mineral-associated.

Mayotte

Design &

Engineering