How Did The Dirt Get So Dirty?

Sources of NYC Environmental Impacts

Have unanticipated delays or cost overruns occurred on your project as a result of previously
unidentified impacts in the subsurface? In many cases, the source of the contaminants is
unknown, and many ask the same question, “Where does the contamination come from”? This
is an interesting question because many may not have given it much thought. We react to the
knowledge of contamination, but often do not consider how it got there and the potential
sources, whether the source(s) originates from the site, from off site, or both.
New York was once the center of manufacturing and commerce in the country and just about
anything and everything was produced, stored, or transported from sources right here. As a
result, all types of historical contaminants may be present beneath the pavement and buildings
in New York City, but most contamination stems from the everyday materials required in running
a city.
Coal Tar
Before the widespread use of natural gas, coal gas was used to light and heat the five boroughs.
Coal gas was produced by numerous plants around the City that burned coal in the absence of
oxygen. This process produced a useful gas that lit the homes and streets of New York but left
behind a toxic coal tar waste. The waste coal tar was more often than not disposed of improperly.
These former coal gasification plants were scattered throughout the City and operated from the
1800s through the 1950s, until they were ultimately consolidated by the major utilities. From this
example a key point emerges: we often think of environmental contamination as being linked to
a singular event—a spill, pipeline burst, a disaster. However, although these exist, the most
common source of contamination isn’t a singular environmental catastrophe, it is the fallout from
meeting our everyday needs. With coal gas, the all-encompassing need for heating and lighting
was the impetus resulting in a large footprint of toxic coal gas-related waste throughout the City.
Below are some similarly common contaminants throughout the City and their links to common
daily needs of New York.
Lead, a great health concern, comes not only from coal ash and atmospheric deposition, but also
from the former use of tetraethyl lead added as an anti-knock agent to gasoline and from lead
paint. Leaded gasoline emissions from vehicles left lead behind in soils all over the City and lead
paint was extensively used for decades. Banned for indoor use in 1976, lead paint remains in old
buildings and finds its way into soils from demolished buildings and flaking from outdoor
Coal Ash
Coal was utilized throughout the City in abundant quantities for heating and power. Vast
quantities of coal were burned in furnaces in New York for more than a century leaving behind
huge amounts of coal ash as residue. In the 1950s, the daytime skies in the City were often dark
or cloudy from so much coal smoke. Much of this waste was used as fill material throughout the
city or simply dumped. To save money, it was moved to fill in depressions and wetlands. Coal ash
contains heavy metals such as arsenic, cadmium, mercury, chromium, selenium, nickel, and lead,
and polycyclic aromatic hydrocarbons (PAHs). Coal ash is found on many sites in the City. We see
it in many soils/fill throughout the City.
Chlorinated solvents like tetrachloroethene (PCE) and trichloroethene (TCE) are regularly found
in soils and groundwater. Potential sources include metal finishing, automotive repair, as they
work great to remove oils, and from ordinary dry-cleaning operations. While disposal has been
controlled since the 1970s through the Resource Conservation and Recovery (RCRA) Act, their
long-term, widespread use left large amounts in the environment, where untreated they
breakdown very slowly. Discharges of PCE and TCE to the ground surface or through illegal or
improper handling penetrated concrete and asphalt and into the underlying soils and
Underground / Aboveground Storage Tanks
And then there are the ubiquitous underground storage tanks (USTs) and aboveground storage
tanks (ASTs). These held vast quantities of fuel oil for heating, gasoline, and all manner of solvents
and other chemicals. USTs/ASTs have increased failure rate with age due to corrosion, improper
installation, and differential settlement, resulting in leakage. The number of registered and
unregistered USTs and ASTs in the City is uncountable, and we find undocumented USTs on
almost every site—don’t rely on your Phase I to list them all. Historical discharges from storage
tanks have caused extensive impacts trough out the City.
Some of this may be known to you, but did you know NYC used to be home to many copper
smelters back in the day. Copper ore, containing impurities, was smelted here to process the ore
into metal. This gave rise to atmospheric deposition of heavy metals such as arsenic and
selenium. And what of the spent ore after processing? Often it was used to fill wetland areas
where copper and arsenic, among other metals, may be found in the fill.
Classification, Investigation and Remediation
Throughout the City these contaminants led to the many properties being classified as “E”
Designation and or Brownfield properties. Resolving issues with the “E” Designation and
Brownfield programs has become our specialty. FLS has found historical impacts on Brownfield
and industrial sites throughout the City, and has successfully worked with regulators to resolve
these issues. FLS has combined our knowledge of history and expertise in environmental
investigation to navigate our clients through the complexity of these programs.
Identifying these impacts in the soil, groundwater, and soil vapor adds complexity to conceptual
site modeling and the development of remedial scenarios. Our innovative approaches to
investigating these properties has led to quick approvals with regulatory agencies. Remedial
strategies include statistically based sampling approaches that better identify the location and
extent of contamination, while typically reducing the contaminant extent, and treatment plans
that more accurately target the contamination and have fewer surprises. These include more
surgical excavation and/or in situ injections.
For over 40 years FLS personnel have successfully handled our clients’ issues in a timely and cost-effective manner, assuring our clients of the proper case closures and successful re-development
or repurposing of their projects. Our innovative approaches have saved our clients millions in
redevelopment costs.
If you have any questions regarding our services, please give us a call at 212-675-3225.