Conversations on Conservation
“Breaking the Ice – Impacts of
Road Salt”
Hosted by
Westchester County Parks
Department
Westchester County Center
January 27, 2006
Town
of Bedford Conservation Advisory Board
Angelo
Spillo – Director of
Pace University Environmental Center
This
is the fifth of our morning cafes and it was put together by a number of
people. We have an ongoing committee made up of people from Westchester Parks and Planning, Friends of Westchester County
Parks, The FCWC, The Nature Conservancy and Teatown Lake Reservation.
When
we first discussed the topic of salt, it was early in the season and I said to
myself, I don’t think this is going to go over very well because every one has
already purchased their salt and it’s late in the season and we probably won’t
get a big turnout. I was wrong because I guess we hit on a timely and
interesting topic. I would like to introduce our next speaker. He is the
Commissioner of Public Works for White Plains and also the city engineer. He over sees a number of public works bureaus
for the city and implements energy saving projects within the city.
Joseph (Bud) Nicoletti (Commissioner of Public Works of White
Plains and City Engineer)
I
am here to present the issues. It’s hard to think about the summer’s clear
roads in the middle of a snow storm. If you are a public works official to
think as if it were summer time. If you see snow coming down, you throw salt
on, more salt on, throw liquid de-icer on, throw everything we have on it. But
then, all of that material is causing other problems and that’s the other side
of this coin. When the sun finally comes out in the summertime, then you see
dead fish or plant life that have been compromised for the necessities of
de-icing. At the time it seems like the thing to do.
There
is a lot more pressure that roads stay open than ever before.
Snow
chains - They slow
down the car because you can’t drive that fast, but they don’t have the same
stopping ability as you have on dry roads, but it’s the best way to stop on
snow or ice.
All
season tires – While
the vehicle goes well, it doesn’t stop any better. The rubber on winter tires
is either hard or soft, it is able to bond to the ice on the road and is a lot
more flexible. That having been said, people just drive faster. SUV’s are not
any safer in snow than any other car although people drive them as if they
were. There should be increased pressure on the public to drive slower. Every
municipality is under pressure to produce bare pavement immediately after a
snow storm. This is environmentally difficult.
Short term driving safety compromises the long term safety of the
environment. Trucks are capable of
spreading more tons of salt per hour, but should that be done? Probably not,
but it is done because of public demand.
Road
temperature sensors
are a very important tool because the air temperature doesn’t give you the
whole story. You can more carefully control the amount of de-icers that are
used and the amount of plows that you have to put out.
The
mental mindset of the driver
is a real problem – he cannot get the idea that it is winter and snowing and
gets annoyed if someone gets in front of him. He drives too fast and usually
ends up off the side of the road.
Trucks
will rust out because of salt and you have to get rid of them before there are
any mechanical problems.
Another
problem is law suits. You get sued if there’s not enough salt and the
roads aren’t “properly taken care of” and you get sued if you are polluting.
James J. Dean (Superintendent of Highways for the
Town of Orangetown, NY)
There
are 50,000 people town wide and about 35,000 people that our highway department
gives direct service to. We have 143 miles of town roads and we do all the
state roads except for the PIP on a contract basis. We also do about 16 miles
of county roads. We have 23 plow routes, each one averages about 8 miles/truck.
We
used to use cinders which were very granular. There were a couple of factories
that burned coal in Orangetown that gave the town the cinders. After the
factories stopped using coal, we went to sand. We found that we had to put salt
in it to keep the sand from freezing. That’s how we got into using chemical
de-icers. We ran out of natural sand and now we are using manufactured sand
which is the fine particles from crushed stone.
We
found that when we plowed we created hard pack which was very difficult to get
rid of. It takes about 6 times as much
salt to get through the top down to loosen it up so you can clear it off. When
you get a thaw, this stuff is going into catch basins, streams and lakes. Sand
is not the solution. We use a de-icer on top of the pavement so the snow won’t
bond with the pavement.
In
the early ‘70’s, New York State did a comparison of the cost of using sand and
using salt. It showed that it was much more expensive to use sand just to give
moderate traction. It didn’t melt the snow and it didn’t make the roads safer.
You have to put the sand down three or four times more than you would just
using salt. In the mid ‘80’s we found we were doing better by applying salt
directly to the road and stopping the bond than we were doing by using sand. We
ended up using much less sand and had much less cleanup. Sand also creates
particulates and dust and you end up with air quality problems.
There
was a presentation in Kingston on December 6th (2005) in which one
presenter did a study for the EPA to identify where the sodium that is in the
water comes from. They found that 30% could come from water softeners.
Fertilization can cause a lot of salt.
We
all have to be cognizant of using the
right amount of salt at the right time
in the right place. We believe salt is the best thing we have available
right now – it’s the cheapest, it does the job and it doesn’t have to have
serious environmental impact if we do it properly.
Anti
icing is something we
have gotten involved in in Orangetown and I think it’s one of the tools that’s
going to help us do much better in
reducing
the amount of salt we use. It’s the process of putting an ice melting agent on
the pavement before it snows. It has to be in liquid form. Loose salt on
pavement doesn’t work and if you have much traffic and wind, it gets blown off
and ends up in the streams.
The
products that were being used for a long time were magnesium chloride and
calcium chloride. We use that in liquid form to enhance the granular salt
because it makes it work at lower temperatures, and puts it into solution
quicker. We tried using it for anti-icing; putting it on the pavement before
storms, but there are issues with that because there are certain temperatures
near the freezing mark which can cause it to create slippery conditions.
In
other areas of the U.S. a lot of salt
brine for anti-icing is being used. The idea was to have calcium chloride
encapsulated in the pavement and as the moisture would get down into pores, it
would bring up the salt and break the bond. The special mix costs $120/ ton
versus salt which costs $30/ton and the mix was hard to use. We ended up making
the brine ourselves for anti-icing. You have to use it at the right time and
use it realistically. Pavement temperatures are more critical with the other
products. Salt brine gives us a much wider range in which to use it. We can use
it 3-5 hours before a storm (during which time it evaporates) and when a storm
comes, it works.
We
have pavement temperature sensors on all our trucks (they cost about
$500/unit). We know what all the conditions around town are and we can act
appropriately. The salt brine gives us the ability to do this which we didn’t
have before. We have two brine trucks and within 3-4 hours we can go out and do
all of our main roads. We use about 50
gals./lane
mile. We can also put it exactly where we want it. We can change nozzles and
make it into a strip. The ideal way to put salt down is in a much smaller strip
so it begins to work faster and not to spread it all over the road. It doesn’t
go past the rear wheels. It doesn’t
shoot it out to the curb. That’s wasted
material that’s not doing any good. A lot of people are going to center line
spreading (4 feet wide). It can be done
while
you’re plowing. If you plow off the snow you are always going to leave ¾ to ½
inch of snow no matter how good your plow blades are. If you hit that with a
light application, you can clean that off and it continues to stop the bond. If
you leave it and you get heavy traffic on it, and it compacts, you get the bond
forming again and you have to use more material to break the bond. Light applications
frequently help to reduce the overall amount.
Post
storm – after the
storm is over, you send the trucks back out because there are hard pack
spots. You can hit the spots with liquid
and take it away before you have to hit it with granular material. It takes
about 150-200 lbs. per lane mile. There is a concern with the salt brine. We
are putting it down at 23% solution and you have to control that. More is not
better as it can start to go to re-freezing and the same thing happens if the
solution is less than that.
We
have two brine tanks. Our bucket loader
is a 2 yd. capacity. It dumps the material in the tank, it mixes through and
takes less than an hour and we mix 5,000 gallons in the first batch, transfer
it to the second tank and we have 10,000 gallons available. One man does this.
This is completely automated. We are paying $41.24/ton for the salt and it
takes about 115 pounds of salt to create 50 gallons of brine. It costs us about
6 cents per gallon to make it (which includes electricity). It does not include
the capital costs, or the unit which cost about $55,000 to put in place. All in all it’s been very cost effective for
us. The other liquid that we were using cost $30/lane mile for de-icing, but
the brine now costs us about 99 cents per gallon. We use about 7-8 gallons per
ton for pre-wetting. We now supplement the salt brine for that and down to 20
degrees, it works fine. There will be a point where it gets below 20
degrees
and then we’ll go back to using magnesium chloride for lower temperatures. We
use between 4,000 and 4,800 tons of salt per year.
Storage has always been an issue. We all have
sheds and DEC keeps a close watch on that. We have gotten awards for our sheds
from the Salt Institute. They actually come around and check on what you’re
doing and making sure you are keeping up to standard. It’s a good thing for
every community to be part of. There is always spillage from loading or
unloading the shed, so what Clarkstown has done is to have a 20,000 gallon
underground tank for liquid. In the winter time, there is a sewer system for
the overflow, so it can go directly into the system. There are private storage
bins in shopping malls, campuses, etc. and they have to comply with local
wetlands regulations.
Cornell
Local Roads has a program that they put out. It’s a full day course. We just
sent our crew to it. It covers the whole process of salt and ice control. It can be an 8 hour course or a 4 hour
refresher to deal with our storm water Phase 11 requirements. The Cornell group
will come to a town and show them how they should be doing things. The snow
fighter’s hand book can be down loaded from their web site or have Cornell send
it to you. The DEC has their maintenance manuals that they put out. They talk
about application and storage and how to do it right. Cornell also has a
special handbook on salt storage for local officials.
Representative
from International Salt Institute
The
company was started in 1997. After a big salt mine in New York state was
flooded out, the company went to Chile to supplement its supply.
They
brought salt in by vessels because Chile offered them dry rock salt which is
what is needed. You don’t want a solar salt product which is wet and contains
10% water. We have been the supplier of choice because of price. This is a
world market for ships and two years ago when we set our contract for
Westchester County in the summer, sometime in November China needed iron ore
and they bid up the price for ships. There are three salt veins in the United
States. One goes from the top of NYS to Erie, Pa., then comes back up through
Ohio. Another vein is down near Louisiana and the third salt vein is in Salt
Lake City. One is close to the Rochester/Ithaca area.
It’s
not in our best interest to see you overuse salt because that’s what causes the
bad reputation for salt from environmental issues. Actually, I’m in the
de-icing industry and we need to stay on top and learn from you people who use
it.
Corrosion
– There has been a
significant improvement in automobiles resisting salt corrosion. There has been
a big impact on trucks, however. Treated salts such as magnesium chloride
acetate inhibit corrosion, but are very expensive. We sell different products
that reduce corrosion on bridges and high rise parking facilities. We bring in
over 4 million tons of rock salt/year and distribute it. However, there are a
lot of municipalities that ask for pre treated salt.
The
Garden State Parkway had concerns about their toll booths breaking up and
concrete catch basins have been breaking up faster than they used to. Calcium
chloride is better than sodium chloride, but not that much. Westchester
County’s yearly contract is for 100,000 tons for their county roads.
Salt
color – NYS wanted to
show that they are putting salt down and also, salt has been stolen out of
their storage bins. In order to track it, they wanted a dye to be put into the
salt. The salt from Chile that is supplied to Westchester county and NYC is
inherently pink.
The
name of the game is cost and you want the cheapest transportation you can get..
However, the cheapest source of salt comes from off shore and that is Chile.
The ship that will carry 60,000 tons from one point to another is cheaper than
a rail car which would move salt 200 miles.
Environmental
damage – spreading
excessive amounts where road drainage is misdirected, nor is road salt the only
culprit affecting the environment of road side vegetation. There is also
compacted soil, injury to root systems during road construction, changes in
soil and moisture levels due to paving and toxic effects of vehicle emissions.
Because of its exposed nature, the roadside environment often robs plants of
moisture. One state agency reported that gaseous fumes account for the most
wide spread injury to plant life.
Proper
storage – The Salt
Institute will come in and check on salt storage facilities.
Salt
vs. Sand – The cleanup
is very expensive for sand.
Salt
vs. Other Chlorides –
Calcium and magnesium chlorides are effective ice melters, but their cost is
significantly higher. Sometimes 8-10 times higher. It’s also hydroscopic which
makes it difficult to work with. It can be effective in liquid form for
pre-wetting. In the case of urea and potash, potash is very environmentally
friendly (it’s a fertilizer), but potassium chloride is not an effective ice
melter. Calcium magnesium acetate (CMA)
is a good ice melter, but the cost is prohibitive ($1000/ton). There is a
pre-mix which Massachusetts uses. We supply a bulk form of 20% calcium chloride
mixed with the salt.
Pre-wetting –(On the Salt Institute Website)
William
Wegner (Riverkeeper
Watershed Analyst)
Monitors
sprawl in the 2000 sq. mile watershed area that serves NYC’s drinking water supply.
Oversees the city’s development of sound water quality monitoring models,
develops standards for tributary health, reviews EIS’s, participates in town
and county individual projects and provides technical support for anti-sprawl
groups.
Figures
from National Research Council state that Massachusetts, New Hampshire and New
York have the highest annual loadings with Massachusetts being highest with
almost 20 tons per lane mile/year. In the NYC watershed, there are 6,000 miles
of paved roadways. Application on 2-lane town, county and state roads is about
37 tons of salt per lane mile/year. The Taconic gets about 75 tons per lane
mile/year. I-84, which goes through 2 sub basins in the Croton watershed
receives 298 tons per lane mile/year (from a 2000 study by the U.S.G.S.).
There
are guidelines for salt application and the introduction of chlorides and
sodium into surface waters is regulated, but the actual application of road
salt is not specifically regulated.
Environmental
Impacts – There was a
Canadian study that reported damage to roadside vegetation that was 200 meters
away from the actual salt application site. There are direct and indirect
impacts to wildlife because when the vegetation is damaged, habitat is
destroyed – food sources, habitat corridors, migration, shelter, breeding and
nesting sites. There are direct effects when wildlife ingests road salt.
The larger animals lick the salt off the roadways and collide with vehicles,
also some of them have salt deficits and when they eat too much salt, they get
a toxic, behavioral reaction. They become less alert to the vehicles and as a
result don’t get out of the road quickly. The same thing happens with birds.
Some of them mistake salt crystals for grit and as little as 1 1/2 particles
can kill them.
Aquatic
biota – fresh water
fish and crustaceans and insect larvae that are in water have a tolerance to
salt levels. Snow melt creates shock loads to aquatic systems during snow melt.
Human
health – primary
problems of road salt in drinking water is aesthetic – an adverse taste effect.
Up to 30% of the U.S. population could have borderline hypertension and the
ingestion of sodium aggravates hypertension. While it’s not a big problem now,
it could become one in the future.
Expense – Infrastructure impacts, automobile
corrosion, corrosive impacts on concrete reinforcing rods are all costly. Snowbelt states spend between
$250-650 million/year on bridge repairs and parking garages. The northeast pays
between $75-175 million/year for repair and maintenance of infrastructure.
Alternatives -
There are chemical and management practice alternatives. Calcium magnesium acetate (CMA), while
mainly environmentally friendly, can cause temporary oxygen depletion. It’ s
harmless to plants, non-corrosive to metals, non-destructive to concrete. It
does require more application (l ½ :1 ratio) for it to be effective. It’s very
costly. Road salt is approximately $50/ton, while CMA is $800-$1,000/ton. It
can be used in environmentally sensitive areas such as along a reservoir. Unless the cost comes down, there are going
to be budgetary constraints for the municipalities.
KA
(potassium acetate) is very similar to CMA in that it is relatively
environmentally benign. It is also very expensive ($700-800/ton) in 1991.
Trying
to keep the maximum daily loads of phosphorous into the reservoirs low, the DEC
has established the maximum daily phosphorus loads.
Sensors – Some municipalities are using
sensors. They reduce salt application because it is not done until the temperature
is approaching freezing at the pavement. In a pilot study in Vermont they
returned 850% on their investment of sensors because of the reduction of road
salt usage. They reduced salt usage 28% on average and saved over $2
million/year.
Leila Goldmark (Riverkeeper Watershed Attorney)
Leila
investigates and prosecutes clean water act violations, fights sprawl in the
NYC watershed and conducts Riverkeeper’s wetland protection campaign.
The
best way to reduce road salt usage is educating the public. Last year there
were some recent studies in July which highlighted the potential problems we
are all facing. The study covered three watershed areas one of which was the
Mohawk watershed in the Hudson River valley and they compared data from the
last 20-40 years. They found chloride
concentrations
up to 25% the concentration of sea water and up to 100 times greater than
un-impacted forest streams during summers.
The
U.S. uses about 18 million metric tons of rock salt/year in the northeast and
mid-western states alone. Six states, including NYS use 75% of this total. Salt
goes from the road and accumulates in the soil and moves relatively slowly. We
are now getting to a saturation point where it is moving further and being
pushed into our groundwater supplies and coming out in the surface waters.
We
are doing policy initiatives and working on finding solutions to potential
contaminants that are not regulated.
How
serious is the NYC watershed problem now? There has been salt contamination in
private wells, among other problems.
We
are surveying towns to find out what they are doing. Conditions vary from
valley to valley and we want to know what’s working with those of you here.
Some
areas have reduced applications of salt for environmental reasons. Pound Ridge has re-classified the roads in
pre-sets based on location and usage and in the past three years they have had
a 30% salt reduction.
We
are trying to do some pilot studies with communities that may not be using some
of these alternatives and see if we can document before and after change. It’s
hard to sell the alternatives unless you can back them up with numbers.
If
you put cost, safety and environmental benefits, it seems you could pick any
two, but not all three. It would be nice to get to the point where all three
would be able to be accomplished.