Tag: stormwater management

Managing Nutrient Pollution in Our Water

Runoff of phosphorus and nitrogen from farming, stormwater, and wastewater treatment plants is an increasing issue for aquatic environments around the world. While phosphate and nitrogen are natural and necessary components of aquatic ecosystems, too much can be dangerous. Excess amounts of these nutrients, also known as nutrient pollution, is detrimental to plants, wildlife, waterways, and our own public health. Although this issue is not new, there’s been an uptick in awareness as water and wastewater utilities aim to improve drinking water quality and meet regulatory requirements.

 

Problems with Excess Nutrients

Nutrient pollution is a widespread problem that affects rivers, streams, lakes, bays, and coastal waters across the country.

 

Algal Blooms

Increased levels of phosphorus and nitrogen can cause harmful algal blooms that ultimately lead to the production of toxins and elevated bacteria levels that are harmful to people and wildlife. In fact, nutrient pollution can cause issues in water quality both near and far from the location where the nutrients enter the water source. A study from the US Water Alliance noted an instance of water pollution where excess nutrients from the Mississippi River Basin caused toxic algal blooms 2,300 miles downstream in the Gulf of Mexico. The algae later decomposed, all while consuming large amounts of oxygen and creating dead zones in which aquatic organisms could not survive.

 

harmful algal blooms covering a body of water

 

Treatment Costs

When it comes to treating wastewater and providing high-quality drinking water to customers, costs will rise for water utilities should the water be saturated with excess nutrients.

 

Recreational Opportunities

The problems that stem from excess nutrients in water bodies negatively impact the livelihood of those who use the water for recreational purposes. According to the EPA, the US tourism industry loses nearly $1 billion each year, while the commercial fishing industry loses tens of millions.

 

Sources of Excess Nutrients

Most excess nutrients in the water originate from agricultural runoff, urban stormwater, and discharge from wastewater treatment plants. There are two types of sources – “point” sources and “nonpoint” sources. Point sources typically refer to industrial and municipal wastewater treatment plants. Nonpoint sources refer to agricultural and stormwater runoff.

 

Point Sources

$1.4 trillion in public funding has been invested in improving municipal wastewater treatment facilities to address nutrient pollution since 1972.

 

 

Nonpoint Sources

The primary approach to reducing nutrient pollution of agricultural nonpoint sources has been the implementation of ‘Best Management Practices’. Best practices vary on a farm-by-farm basis and have the potential to be cost-effective or expensive, depending on several factors. Because farm practices are unpredictable due to cropping patterns, soil properties, hydrology, and weather, many farmers are hesitant to change their current practice. Compared to point sources, a mere $5 billion has bene spent by the federal government to incentivize farmers to implement strategies for nutrient reduction. Additionally, when it comes to nonpoint sources of excess nutrients including stormwater, a lot more can be done on the ground level. Being mindful of what goes down the drain in our yards, and on the streets, can have a huge impact.

 

Efforts for Reducing Nutrient Pollution

There are many programs in place on both the federal and state level to help reduce nutrient pollution levels. Below are just a few.

 

The Clean Water Act

This Act regulates point source discharge and requires all dischargers to obtain a National Pollutant Discharge Elimination System (NPDES) permit from the state. NPDES permits enforce limits on the concentration of nutrients that can be discharged into surface waters. Under Section 319 of the Clean Water Act, the EPA also supports state efforts to reduce nonpoint sources of nutrient pollution with its $160 million grant program. According to the EPA, activities supported by these programs may include implementation of state nonpoint source management plans, state regulatory and non-regulatory programs, watershed prioritization and planning, and nonpoint source monitoring.

 

Financing

Several loans exist specifically for upgrades and construction of wastewater facilities. The State Revolving Fund program offers low-interest loans for wastewater treatment infrastructure, and the USDA’s Rural Development Water and Environmental Programs provide long-term, low-interest loans and grants for the construction of these facilities in rural communities. The USDA and EPA also support the reduction of nutrient pollution by incentivizing voluntary action by nonpoint sources. There are a handful of programs that provide a mix of funding directly to farmers, or to groups at the community or state level.

 

Partnerships

The EPA and five other federal agencies co-lead the Gulf Hypoxia Task Force. This federal initiative was developed in 2008 (and adopted by 12 states) to reduce nutrient loads by 20 percent by 2025 and by 45 percent by 2035. Other partnerships created to reduce the impacts of nutrient pollution include Source Water Collaborative and the Animal Agriculture Discussion Group.

 

Outreach

The EPA is working with its partners to combat nutrient pollution in water bodies throughout the country. They’ve created a wealth of communication and outreach materials to increase awareness of the causes, effects, and solutions to nutrient pollution.

 

Conclusion

In conclusion, we must continue addressing the problem of nutrient pollution in water bodies across the country. While there are several initiatives in place to combat the harmful effects of nitrogen and phosphorus entering the environment, nutrient pollution is increasing at a quicker rate than what is being done to eliminate it. Federal and state agencies, farmers, and even you can play a tremendous role in reducing nutrient pollution. Learn what you can do within your community here.

6 Ways to Help Prevent Stormwater Pollution this Spring

You know what they say; April showers bring May flowers. While the start of spring and warmer days to come is certainly exciting, it’s important not to oversee what else comes with an increase in seasonal rain – stormwater pollution. Stormwater is water that comes from precipitation and snow/ice melt. The water either soaks into exposed soil or remains on top of impervious surfaces like pavement or rooftops. Most stormwater will eventually evaporate, but often times it will flow as runoff to another location. As the water runs it picks up pollutants along its path including debris, sediment, pesticides, fertilizers, pet waste and more. This polluted stormwater can cause soil erosion, stream impairment, flooding, fish and wildlife habitat loss, and reduced groundwater levels. Although stormwater pollution cannot be eliminated completely, you can do your part in preventing it. Check out these six ways to help prevent stormwater pollution this spring.

stormwater drain leading into creek

1. Only Rain Belongs in the Drain

As you start a spring cleanup in your yard, it’s important to remember that storm drains are not garbage disposals. Substances including leaves, yard waste, and other debris should be disposed of properly, and not released into neighborhood drains. Do your part to ensure that the only thing flowing into the storm drains are rain and snow/ice melt.

2. Use Lawn Chemicals Sparingly

With the arrival of warmer weather and outdoor summer fun on the horizon, now is the time when people start getting their lawns in tip-top shape. When it comes to fertilizer, remember that a little goes a long way. While a 20-pound bag of lawn fertilizer may seem small, do note that it will typically cover up to 4,000 square-feet of space (bigger than a tennis court). When spreading the fertilizer, use it sparingly to assure the excess does not overflow into runoff when rain comes. Choosing an organic fertilizer will also be less detrimental to the environment.

man fertilizing lawn

3. Avoid Over-Watering Your Lawn

While fresh, green grass is the end-goal for most yards come springtime, be sure not to over-water your lawn. In addition to the risk of fertilizer flowing over and out into the streets, it’s not good to have pools of water collecting in your grass. Avoid this by scheduling times each week to water your lawn, or by turning on sprinkler timers.

4. Wash Your Car Over Grass or Gravel

If you plan to wash your car at home, find an outdoor surface such as gravel, stone or grass to wash it on. Soapy water and grime will have an easier time neutralizing if it is filtered out before it reaches our streams and creeks. Try using a non-toxic or biodegradable soap as well to allow fewer chemicals to get into the water. An even safer alternative would be heading over to your local car wash where they will have a system in place for recycling or removing wastewater.

kids washing car at home

5. Pick Up Pet Waste

Although this sounds like a given, there are still many folks who do not pick up their pet’s waste. Pick up, bag, and dispose of pet waste properly to assure that unhealthy bacteria is not flowing into local waterways.

6. Plant Low-Maintenance Grasses and Plants

When it comes time to choose either grass seeds for your lawn or decorative plants, go with a low-maintenance, native (ones that occur naturally in a region in which they evolved) option. Because native plants adapt to local environmental conditions, they require far less water and are a lot better for the environment. Curious about what types of native plants are in your area? Check out this Native Plants Database to find out!

Interested in learning more about eco-conscious stormwater management to avoid stormwater pollution? Check out our infographic here and keep these tips in mind as you get going on your spring activities.

 

It Takes a Village to Manage Stormwater

stormwater_street_drainWhat’s the big deal about stormwater? After all, it’s just rain, right? Not really. Rain or snow that lands on pervious, or porous, surfaces such as forests, gardens, or fields soaks into the ground and is naturally filtered and cleaned by layers of dirt and rocks, after which it finds its way to groundwater and drinking water supplies. Stormwater is precipitation that runs off impervious surfaces, such as rooftops, paved areas, lawns, and bare soil, directly into lakes and streams. Because it does not infiltrate and is therefore not filtered prior to entering ground or surface waters, stormwater is contaminated by everything it picks up along the way. These pollutants include but are not limited to pesticides, motor oil, gasoline, antifreeze, road salt, trash, fertilizers, sewage, bacteria, and pet waste, and they wreak havoc on drinking water supplies.

Common problems associated with waters polluted by stormwater include bacterial and nitrogen overload, low-oxygen dead zones, toxic algae blooms, litter-strewn waterways, damage to coastal marshes, and beach closures. In addition, pollutants carried by stormwater can harm or kill fish and wildlife, destroy vegetation and wildlife habitats, and foul drinking water. And all of these problems come with a very high environmental and monetary price tag. The most cost-effective way to manage stormwater pollution is to prevent it in the first place, which requires the cooperation of the government, municipalities, and individuals.

How the Government Helps

The United States Environmental Protection Agency (EPA) has instituted stormwater regulations under its Clean Water Act, which aims to protect our nation’s water so that it is clean, drinkable, fishable, swimmable, and healthy. The National Pollutant Discharge Elimination System (NPDES) Permit Program controls water pollution by regulating point sources that discharge pollutants into waters of the United States. Three specific contaminants of concern are bacteria, phosphorus, and nitrogen, and many of our nation’s rivers, streams, and lakes are already widely contaminated by these pollutants.

NPDES Municipal Storm Water Permitting Program regulates stormwater discharges from municipal separate storm sewer systems (MS4s). MS4 refers to systems including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, and storm drains that are owned or operated by a state, district, county, city, town, or other public body (created by or pursuant to state law).

Phase I of the NPDES stormwater program for MS4s requires operators of medium and large MS4s, or those that serve populations of 100,000 or greater, to implement a stormwater management program in order to control polluted discharges from these MS4s. Phase II extends coverage of the NPDES stormwater program to certain small MS4s, but utilizes a modified approach to how the stormwater management program is developed and implemented. 

How Municipalities Help

parking_lot_impervious
Stormwater fees are based on the amount of impervious surfaces on a property

Increasingly, municipalities are addressing the issue of stormwater through regional collaboratives, education, legislation, and taxation. Last January, the Portland, Maine City Council unanimously voted to charge property owners a stormwater fee, which is dependent on the size of their rooftops and driveways or parking lots. The fee goes into effect this coming January and will cost the average homeowner roughly $4.50 per month, but will have a much larger impact on businesses like L.L.Bean, which will incur a monthly fee of just under $10,000. Several other municipalities in New England have implemented similar fees, including Chicopee, Fall River, Northampton, Newton, and Reading, MA, and Burlington, VT. Across the nation, over 500 municipalities, including major cities such as Minneapolis, Baltimore, Charlotte, Des Moines, Philadelphia, Seattle, Salt Lake City, and Orlando, have also begun imposing stormwater fees. While many residents and businesses have complained about this alleged “rain tax,” the fees actually assist with the remediation and cleanup necessary due to stormwater pollution, which is exacerbated by impervious cover. It is possible for homeowners and businesses to reduce stormwater fees by reducing the square footage of their property’s impervious surfaces.

Regional collaboratives, aiming to comply with the NPDES Permit Program, are becoming increasingly common with MS4 permittees. These collaboratives, such as the Central Massachusetts Regional Stormwater Coalition (CMRSWC) in south-central Massachusetts, hold workshops together with stormwater engineering consultants in an effort to determine the most essential tasks for stormwater management as well as the critical content of each task. With this method, these municipalities are able to pool resources to identify and implement the most efficient, cost-effective methods of meeting MS4 Permit compliance within their communities.

green_roof_stormwater
Green roofs help manage stormwater in urban settings

How Individuals Can Help

Mitigating stormwater pollution requires a multi-faceted best practice approach that involves not only federal and local agencies and municipalities, but also homeowners and individuals. There are many ways for individuals to reduce stormwater pollution including cleaning up and properly disposing of pet waste in a timely fashion, maintaining healthy septic systems, reducing or eliminating the use of pesticides and fertilizers, and implementing cleaner automotive operations. In addition, homeowners may implement Low Impact Development (LID) practices on their property to manage stormwater and to save water. Some of the easiest and most cost-effective LID practices include installing rain barrels, rain gardens, green roofs, and permeable pavers. Comprehensive information on LID may be found here, and of course, public education is key. Some other important ways that individuals can mitigate stormwater pollution are as follows:

ladybug_pest_management
Ladybugs are a natural predator to pests such as aphids

        • Unclog residential storm drainages that become blocked
        • Cover truck loads or piles of dirt, mulch, yard waste, and other debris
        • Dispose of chemicals, such as motor oil, paint, and grease, properly
        • Have septic systems professionally inspected and pumped at a minimum of once every three years
        • Wash vehicles on on the lawn or other unpaved, porous surface
        • Direct downspouts away from paved surfaces and clean roof gutters annually
        • Check vehicles for leaks
        • Avoid pesticides by utilizing Integrated Pest Management (IPM)
        • Cover bare spots in the yard with plants, rocks, or even a water garden
        • Sweep driveways and walkways instead of hosing them off
        • Make sure all trash containers are tightly covered so that trash doesn’t enter the environment

Rain gardens filter stormwater, provide habitat for wildlife, and beautify the area
Rain gardens filter stormwater, provide habitat for wildlife, and beautify the area

Because the monetary and environmental cost of damage caused by stormwater is so exorbitant, it is imperative that communities take action to proactively prevent stormwater runoff before it causes damage. The old adage about an ounce of prevention being worth a pound of cure is quite applicable in the case of stormwater, as methods for stormwater prevention are both inexpensive and simple to implement, whereas cleanup and treatment are costly. However, best stormwater management practices require cooperative involvement of governments, municipalities, businesses, and residents. In other words, it really does take a village to manage stormwater.

Managing Stormwater in New England with Low Impact Development

10 Best Low Impact Development Stormwater Practices

Stormwater runoff is the number one source of water pollution in the country, and a major threat to clean water in many New England communities. Over the years, we have paved, constructed, and developed the land to the point that the natural landscape is decimated. Where snow, sleet, and rain would normally land on forests and grass and be filtered by layers of dirt and rock, it now washes off parking lots, roads, driveways, rooftops, and other hard surfaces, known as impervious cover, and picks up pollutants such as oil, trash, sediment, bacteria, fertilizer, oil, and road salt along the way. This heavily polluted, untreated water then makes its way into streets and storm drains and subsequently into rivers and lakes that supply our drinking water.

In Texas and Oklahoma this week, we’ve seen the devastating and deadly effects of stormwater runoff. Because the absorbent grasses and dirt have been mostly covered over by pavement and buildings, heavy rains now run off streets, roofs, and driveways, overwhelming drainage systems and, in extreme weather, flooding homes. And in New England, stormwater runoff has not only contributed to water pollution and flash flooding, but also to beach closures, algae blooms, and soil erosion.

What is Low Impact Development?

Low Impact Development (LID), also known as green infrastructure, is a stormwater management approach that maintains natural hydrology during site development. LID minimizes impervious surfaces and utilizes existing natural site features along with conservational controls to manage stormwater. In LID, stormwater is viewed as a resource rather than a waste product, and the site is developed with this key concept in mind. Often, LID replaces traditional stormwater management practices that focus on moving stormwater off-site with curbs, pipes, and ditches.

LID is useful for creating functional, attractive, and environmentally friendly residential, commercial, and industrial sites, and is both sustainable and cost-effective. Some of the benefits include improved water and air quality, reduced stormwater runoff volume, increased natural habitat and recreational space, increased property values, improved groundwater recharge, and community beautification. Below we have compiled a list of ten LID stormwater practices that are most effective in managing stormwater in New England.

rain_garden_stormwater

1. Rain Gardens

A rain garden is typically situated close to the source of runoff and utilizes plants that are able to withstand extremes of moisture as well as excessive nutrients such as nitrogen and phosphorus. By slowing stormwater as it travels downhill, rain gardens provide opportunity for stormwater to infiltrate and also inhibit erosion. While rain gardens provide habitat for wildlife and are an attractive landscaping addition, it’s what’s beneath them that makes them an LID rain garden. Plants and soils are specifically chosen and engineered to clean stormwater by reducing nutrients and overall sediment loads. Multiple rain gardens are often spread over an area, cumulatively controlling the volume and improving the quality of stormwater runoff.

green_roof_fenway_park

2. Green Roofs 

A green roof, also knows as a rooftop garden, is exactly what its name suggests: a roof with vegetation on it. Through evapotranspiration, green roofs remove heat from the surface of the roof and in turn the surrounding air. A green roof is easily installed on any type of building, residential or commercial, and can be as simple as a single layer of groundcover or as intricate as Fenway Park’s extensive vegetable garden. In addition to providing excellent stormwater management and improving water quality, green roofs also provide such benefits as reduced energy use and air pollution, and improved comfort and quality of life.

permeable_pavement_stormwater

3. Permeable Pavement

The link between high levels of impervious surfaces and degraded water quality is indisputable, and most impervious surfaces are paved roadways. Reducing impervious surfaces is one of the key steps in improving any community’s water quality. Permeable, or pervious, pavement is designed to allow water to pass through it into the ground below where it is naturally filtered. Pervious pavement has a myriad of benefits including not only reduced stormwater runoff and replenished groundwater, but also reduction of flooding, pollutants, temperature, roadway ice buildup, and traffic hydroplaning accidents. In New England, special care needs to be taken when utilizing permeable pavement, as there is potential to compromise its effectiveness through plowing and sanding.

grassed_swale_stormwater

4. Grassed Swales

A grassed swale is an open channel designed to manage a specific water quality volume, often along roadsides and parking lots. Stormwater runoff is slowed by vegetation as it flows in these channels, allowing the stormwater to infiltrate and be filtered by the underlying soil. Grassed swales are long and shallow in shape and have plants that are both flood and erosion resistant.

grassed_swale_stormwater

5. Disconnected Impervious Surface (DIS)

DIS is a low-cost, effective way of reducing the volume and flow of stormwater runoff by directing stormwater runoff from impervious areas to graded and vegetated pervious surfaces. DIS is effective for both roofs and paved areas utilizing slightly different designs and provides both infiltration and filtration.

bioretention_basin_stormwater

6. Bioretention Basins

Bioretention basins are landscaped depressions specifically designed to slow and treat on-site stormwater runoff. Typically utilized in parking lots and residential areas, these basins incorporate pollutant removal systems that naturally operate in forests. During a storm event, runoff pools above the mulch and is slowly filtered through the soil beneath before being collected by a perforated underdrain. The clean, filtered runoff is then returned to the storm drain system or local receiving waters.

green_streets_stormwater

7. Alternative Street Design

Alternative street design is mainly effective for new construction and takes into account all aspects of “green streets.” When building a new street, all existing hydrologic functions of the land need to be considered and incorporated in the best possible way into the design. This includes preserving wetlands, buffers, and highly permeable soils while minimizing impervious areas. Typically streets are more narrowly constructed with wide, pervious sidewalks and plenty of vegetated areas.

stormwater bumpout

8. Bioretention Curb Extensions (Stormwater Bumpout)

A stormwater bumpout is a curb extension that extends the existing curb. Typically located either mid-block or at an intersection and composed of a layer of stone that is topped with flood and nutrient tolerant plants and soil, these attractive bumpouts filter stormwater while providing an aesthetic benefit to communities. The bumpout is constructed with an inlet (or curb-cut) that directs stormwater runoff into the bumpout where it can be infiltrated and filtered. The vegetation in a stormwater bumpout is short enough so as not to impact driver sight-lines.

stormwater planters

9. Stormwater Planters and Tree Boxes

Stormwater planters and tree boxes are installed in sidewalks and are designed to manage stormwater runoff from streets and sidewalks. Planters are typically sunken into the sidewalk, rectangular in shape with concrete sides, and lined with a permeable fabric. They are then filled with stone or gravel and topped with soil, hardy plants, and trees. Because they are built down into the sidewalk, runoff is directed into these planters that provide storage, infiltration, and evapotranspiration.

rain cistern stormwater

10. Rain Barrel/Cistern

A rain barrel collects and stores stormwater runoff from rooftops, where it can later be used to water lawns and gardens. To be effective, they must be emptied between storms and utilized by a high percentage of a community’s population. While one rain barrel holds a relatively small amount of water, a large volume of rain barrels can be extremely effective in significantly reducing the amount of stormwater entering a community’s sewer system during storms.

lid-stormwater.net
lakesuperiorstreams.org
nrdc.org
epa.org
lowimpactdevelopment.org
msrc.org
phillywatersheds.org

Green Changes Ahead in Stormwater Management

An enhanced tree pit helps mitigate runoff. Photo courtesy of NYC Environmental Protection.
An enhanced tree pit helps mitigate runoff. Photo courtesy of NYC Environmental Protection.

EPA looks to incorporate green infrastructure into new stormwater regulations in 2014

Spring 2014 will likely see the long-overdue proposed national stormwater regulation from the EPA. In addition to anticipated changes such as stronger reporting requirements, publicized Stormwater Pollution Prevention Plans (SWPPP), and clarified corrective action conduct, the EPA aims to integrate green practices and infrastructure into stormwater initiatives. These initiatives will have positive impact to both the environment and the economy.

Impact of Stormwater

Urban stormwater is a leading source of impairment, and its impact to water quality is growing. Currently, 800,000 acres are being developed annually, and that number is expected to grow to over one million acres by 2040. Development increases impervious cover, and even the smallest increase in impervious cover causes major impact to water reception. In addition, upstream development directly affects downstream waters, and many communities already have waterbodies that have been polluted by stormwater discharge. Clearly, innovative and effective stormwater management practices are imperative to the health of our nation’s waters.

Changing the Way We Approach Stormwater Management

Traditional stormwater management strategies involve the swift conveyance of stormwater from site to waterbody or detention ponds, and the management of peak flows and drainage to mitigate flooding and large-scale downstream erosion. The new approach to stormwater will be to manage municipal stormwater discharges on a watershed basis, particularly MS4 communities, and to integrate green infrastructure into project design during development or redevelopment. This green approach will provide the most cost-effective opportunity to manage stormwater at its source by preventing water quality degradation in healthy waters and helping to restore already impaired waters.

The EPA is considering a number of performance standards for the upcoming proposed ruling, including a retention-based standard to require that sustainable stormwater controls be incorporated into sites as they are developed and redeveloped, thereby reducing volume and velocity of discharges as well as pollutants. The EPA has made it clear that there are indeed cost-effective ways of meeting the standard, including incorporating controls in the site design by preserving vegetation and reducing impervious cover, and integrating green infrastructure practices into landscape or other common areas. The ruling will contain some flexibility, taking into consideration an area\’s climate and other location-specific characteristics as well as redevelopment site constraints and phased implementation. In addition, there may be additional incentives for smart growth and brownfields development.

A porous concrete sidewalk filters rain back into the ground instead of the sewer system. Photo courtesy of NYC Environmental Protection.
A porous concrete sidewalk filters rain back into the ground instead of the sewer system. Photo courtesy of NYC Environmental Protection.

Benefits of a Proposed Stormwater Rule

  • Improved recreational, aesthetic and non-use values
  • Lower drinking water treatment costs
  • Lower dredging costs for navigational channels
  • Reduced siltation of water storage reservoirs
  • Reduced downstream flooding damage
  • Groundwater recharge
  • Small stream erosion and water quality impacts

Vegetation

  • Improved air quality and reduced human health impacts
  • Higher off-site property values associated with green infrastructure
  • Carbon uptake by plants
  • Reduced energy use by buildings and associated air quality
  • Carbon footprint benefits

Community

  • Reduced flooding
  • More livable communities
  • Increased property values
  • Avoidance of extremely high costs of water restoration

UF winners copy

Students at the University of Florida won the EPA\’s 2012 Campus RainWorks Challenge with this green infrastructure design. Read about it in detail here.

In Conclusion

It is imperative that we protect our nation’s most precious resource, and stormwater management is a crucial facet of that goal. The expected spring 2014 EPA stormwater rulings will likely bring significant green infrastructure initiatives, and not a moment too soon. Green infrastructure will serve as an impetus for the critical and cost-effective protection of our water supply with the added benefit of enhancing the world in which we all live.

Road Salt: Taming the Beast

snowman2

Winter is fully upon us, and with it comes frigid temperatures, blustery winds, and, of course, snow. While snow brings fun to northern climates, such as ski trips, snowmen, and peppermint lattes, it also brings a toxic and dangerous contaminant: road salt. Road salt is the primary agent used for roadway de-icing, as it is both effective and inexpensive. However, it wreaks havoc on many aspects of our ecosystem, and it is imperative that we thoughtfully examine how we can protect our natural resources while still maintaining safe roadways.

What Is It?

Let’s start by looking at what road salt really is. Road salt is composed primarily of sodium (Na) and chloride (Cl); however, up to 5% of its composition is made up of ferrocyanide, an anti-caking agent that has been on the EPA’s list of toxic pollutants under the Clean Water Act since 2003, and other impurities such as calcium, potassium, iron, magnesium, aluminum, lead, phosphorus, manganese, copper, zinc, nickel, chromium, and cadmium. All of these components end up in our environment through runoff, melting, and vehicle splash, and have a profound impact on many aspects of our environment.

Water Quality

Winter_Pond_(4251468916)NaCl contamination causes water to have a higher density, and this denser water settles at the bottom of lakes and ponds, preventing oxygen from the top of the water from reaching the bottom. The bottom layer of the water is then unable to support aquatic life due to its oxygen void. Road salt contamination also adversely affects the food supply, health, and reproductive capabilities of aquatic life, disrupting aquatic ecosystems.

In addition, water contaminated with chloride is not easily treated, as only costly processes such as reverse osmosis, ion exchange, and distillation remove it. Sodium in drinking water is monitored due to health concerns in individuals restricted to low-sodium diets, and, because well contamination is often due to road salt runoff, treatment of contaminated private water supplies falls squarely on the shoulders of the Department of Transportation — an expensive responsibility. Due to the alarming increase in road salt usage over the past several years, contaminated water supplies are increasing dramatically.

Animal Life

birds in snowIngested road salt can adversely affect the health of your pets. According to the ASPCA’s website, road salt ingestion, through drinking contaminated puddles, licking paws, or by eating it directly, can cause a myriad of health issues for your pet, from vomiting and diarrhea to seizure and death. In addition, road salt damages the pads of your pets’ feet, making them crack and bleed.

The wildlife population most negatively affected by road salt is birds. Birds eat the salt crystals directly, thinking they are seeds, and they only need to ingest a tiny amount of salt to cause toxosis and death. Also, through its destruction of vegetation, road salt causes depletion of food sources, habitats, and nesting sites for all wildlife. Aquatic populations are also susceptible to road salt contamination, particularly to the anti-caking agent ferrocyanide, which is lethal to fish species.

Plant Life

Road salt damages both aquatic and terrestrial plants by inhibiting nutrient absorption, germination, and flowering, and by causing root damage and dehydration. In fact, NaCl is a registered herbicide due to its toxicity to plants. Plants along roadways act as a protective barrier between pollutants and waters, and destruction of this natural buffer increases water pollution. Road salt also disrupts aquatic ecosystems by eliminating habitats and food supplies and by increasing the prevalence of nuisance algal populations.

Soil

Road salt negatively changes soil chemistry by reducing soil’s pH, decreasing permeability and absorption rates, damaging fertility, and killing beneficial bacteria. Affected soil also erodes at a quicker rate.

Infrastructure

rusty bridge 2Salt corrodes. We notice it mainly on our cars, but it also affects infrastructure such as bridges, support rods, and parking garages. Corrosion poses danger to the public due to compromised structural integrity of bridges and other supported roadways, and it also costs billions of dollars per year in corrosion control and repair costs.

What We Can Do

The best plan of action is to reduce the amount of salt we are using on our nation’s roadways. And this task is certainly feasible. For example, through the Central Massachusetts Regional Stormwater Coalition (CMRSWC), Tata & Howard developed a process providing a roadway treatment calibration approach that maintains safe conditions while reducing chloride loading to surface waters:

  1. salting truckReview and evaluate the types of materials used for roadway treatment on local roadways
  2. Calculate the total loading rate of chloride (in pounds of chloride per lane-mile) presently applied
  3. Compare the calculated loading rates to the range of rates documented in literature
  4. If a community’s current chloride loading rates are statistically higher than documented values, determine if that community may benefit from efforts to alter their current practices
  5. Recommend a phased approach to achieve the potential reduced loading rate
  6. Perform calibration procedures on equipment to deliver reduced chloride loading rates

By performing these steps, CMRSWC communities have significantly lowered their road salt load, resulting in decreased municipality spending and increased environmental protection, all while maintaining safe roadways.

Conclusion

Road salt is certainly necessary, as it remains the best and most cost-effective defense against slippery, dangerous roadways. However, more care and training need to go into salt application. With combined efforts from municipalities, contractors, and engineers, we can drastically reduce the negative impact of road salt on our environment — and still make it to work on time.