The Evolution of the National Wildlife Refuge System: One Manager’s Perspective

Imagining “wild” spaces in and around a busy metropolitan area like Fairfax County might feel like an exercise in futility, but we are actually have several wildlife refuges within driving distance: Mason Neck and Patuxent Research Refuge, for example.

How did these areas become protected and what’s next for the National Wildlife Refuge System that cares for them?

On May 11, at the Northern Virginia Soil and Water Conservation District’s Green Breakfast in Fairfax, Patuxent Wildlife Refuge Manager Brad Knudsen discussed the evolution of the National Wildlife Refuge System. He told stories about the important wildlife resources the NWRS conserves, how the NWRS has grown in its 116 years, and how legislation and public involvement have impacted the direction of the system.

He closed with a glimpse at what the future holds, including decisions driven by science and a mission to take the refuges to the people. Luckily, he’s allowed us to post his slides so that folks who couldn’t come, can still get a sense of what he talked about, and work to preserve our natural national heritage.

 

What I learned during the 2019 City Nature Challenge

Bill Hafker

Participating in the City Nature Challenge was an enlightening and enjoyable experience in several ways.

First, I was somewhat surprised at how many unique living things you can spot when you are really intent on trying to find as many as you can, and you slow down and “get into the weeds” looking for things!

Wool sower gall wasp (Callirhytis seminator), by Bill Hafker

Second, I found that looking at the species identified by others participating in the Challenge was a good source of information for identifying things that I saw. A good example is when I found what I believe now is the wool sower gall wasp. I really had no idea where to start looking to see what this colorful little ball might be, but I found a picture of it in the species list identified by others. Several days have passed and no one has confirmed my ID, alas. Although my pictures are a bit blurry, I think there’s nothing else this could be. I found who the leading identifier of this species was, hoping to engage him in its identification, but could not find a way in iNaturalist to try to contact him.

In addition to looking into how to work with other identifiers, I’ve learned other things to improve my performance next year. This year, I limited myself to submitting only one observation of a species, even if I saw it in more than one area to make observations. I now know that multiple observations are a good way to help define spatial distributions of observed species.

I also realized that, while I received training in how to make observations in iNaturalist prior to the event, I should have sought out training in how to do identifications so I could more actively participate in that aspect of it, also.

Resources for working with native seed mixes in large areas

This resource is meant to be a living document that our community can enrich as they learn. Thank you for sharing generously. If you have additions, go ahead and suggest them in comments, and we’ll update the post.

Seed Companies

Earth Sangha
https://www.earthsangha.org 
May be able to supply a large amount of native plants to plant including seeds if you give them a year to first grow them at the nursery

Ernst Seeds
https://www.ernstseed.com
Virginia Northern Piedmont Mix: https://www.ernstseed.com/product/va-northern-piedmont-facw-mix/

Suggestions

Preparation of the site and the exhaustion of the bank of weed seeds will be critical. Tilling will release a trove of weeds. Future mowing regimens should also be established to mow the annual cool-season weeds in Spring but before the warm-season perennials have taken off.  Mowing will also keep the woodies at bay.

 Consider using seeds for the grasses/flowers, but later use plugs for other flowers, as your budget allows. The flower plugs allow you to have more of an immediate visual impact without breaking the bank. The grasses become the foundation of your planting with the flowers as a smaller, but important, component. (Source: Joe Gorney, President, Fairfax Master Naturalists)

Notes from October 2018 issue of The Acorn, Earth Sangha

Additional notes on plants and conditions, courtesy of Lisa Bright, Executive Director, Earth Sangha 

For meadow-type gardens, you would need sunny and dry-tolerant species to partial-sun and moist-loving species:

  • Little Bluestem (Schizachyrium scoparium)
  • Andropogon virginicus (Broomsedge Bluestem)
  • Purple-top Grass (Tridens Flavus)
  • Beaked Panic Grass (Coleataenia anceps)
  • Southeastern Wildrye (Elymus glabriflorus)
  • Indian Grass (Sorghastrum nutans)
  • Purplelove Grass (Eragrostis spectabilis)
  • Narrow-leaved Mountain Mint (Pycnanthemum tenuifolium)
  • Roundleaf Thoroughwort (Eupatorium rotundifolium)
  • Hyssop-leaved Boneset (Eupatorium hyssopifolium)
  • Flat-topped White Aster (Doellingeria umbellata)
  • Black-eyed Susan (Rudbeckia hirta)
  • Orange Coneflower (Rudbeckia fulgida)
  • Late Purple Aster (Symphyotrichum patens)
  • Early Goldenrod (Solidago juncea)
  • Grey Goldenrod (Solidago nemoralis)
  • Narrow-leaved goldenrod (Euthamia graminifolia)
  • Wild Bergamort (Monarda fistulosa)

For edge of meadow bordering woodlands (sunny most of the time):

  • Deertongue Grass (Dichanthelium clandestinum)
  • Squarrose Sedge (Carex squarrosa)
  • Slender Oatgrass (Chasmantium laxum)
  • Georgia Bulrush (Scirpus georgianus)
  • Bottlebrush Grass (Elymus hystrix)
  • Common Patridge Pea (Chaemecrista fasciculata)
  • Joe Pye Weed (Eutrochium fistulosum)
  • Rough Boneset (Eupatorium pilosum)
  • Woodland Sunflower (Helianthus sturumosus) & (Helianthus divaricatus)
  • Broadleaf Ironweed (Vernonia glauca)
  • Carolina Wild Petunia (Ruelia caroliniensis)
  • Golden Alexander (Zizia aurea)
  • Hyssop Skullcap (Scutellaria integrifolia)
  • Spotted Bee Balm (Monarda punctata)
  • Rough-stemmed Goldenrod (Solidago rugosa)
  • New England Aster (Symphyotrichum novae-anglie)
  • Lyre-leaf Sage (Salvia lyrata)
  • Blue Mistflower (Conoclinium coelestinum)

Partial-sun woodlands: 

  • Slender Oatgrass (Chasmantium laxum)
  • Wood Sedge (Carex blanda)
  • Long-awned Wood Grass (Brachelytrum erectum)
  • Cattail Sedge (Carex typhina)
  • Virginia Wildrye (Elymus virginicus)
  • Bottlebrush Grass (Elymus hystrix)
  • Riverbank Wildrye (Elymus riperius)
  • Poverty Oatgrass (Danthonia spicata)
  • White Wood Aster (Eurybia divaricata)
  • Blue-stemmed Goldenrod (Solidago caesia)
  • Common Dittany (Cunila origanoides)
  • American Alumroot (Heuchera americana)
  • Erect Goldenrod (Solidago erecta)
  • Silverrod (Solidago bicolor)

Streamside woodland edges, full to partial sun: 

  • Deertongue Grass (Dichanthelium clandestinum)
  • Georgia Bulrush (Scirpus georgianus)
  • Common Wood Reedgrass (Cinna anundinacea)
  • Lurid Sedge (Carex lurida)
  • Northern Long Sedge (Carex crinita)
  • Redtop Panic Grass (Coleataenia rigidula)
  • Crown Grass (Paspalum floridanum)
  • New York Ironweed (Vernonia noveboracensis)
  • Blue Swamp Verbena (Verbena hastata)
  • Canada Germander (Teucrium canadensis)
  • Calico Aster (Symphyotrichum lateriflorum)
  • Crooked-stem Aster (Symphyotrichum prenanthoides)
  • Green Coneflower (Rudbeckia laciniata)
  • Common Boneset (Eupatorium perfoliatum)
  • Common Sneezeweed (Helenium autumnale)

Rain garden: 

  • Deertongue Grass (Dichanthelium clandestinum)
  • Crown Grass (Paspalum floridanum)
  • Lurid Sedge (Carex lurida)
  • Frank’s Sedge (Carex frankii)
  • Georgia Bulrush (Scirpus georgianus)
  • Beaked Panic Grass (Coleataenia anceps)
  • Redtop Panic Grass (Coleataenia rigidula)
  • Swamp Rose Mallow (Hibiscus moscheutos)
  • Swamp Rose (Rosa palustris)
  • Blue Swamp Verbena (Verbena hastata)
  • Green Coneflower (Rudbeckia laciniata)
  • Sneezeweed (Helenium autumnale & H. flexuosum)
  • Allegheny Monkey Flower (Mimulus ringens)
  • Foxglove Beardtongue (Penstemon digitalis)
  • Fall Phlox (Phlox paniculata)

Precautions

If “large area” means more than 2500 square feet, including a 10 foot buffer around the bed and any disturbed access to the site, it is a land disturbing activity and may require a permit from the county.

If a “run off” pond is connected to a perennial stream, it may also have a Resource Protection Area (RPA) defined; again you would need a permit. Contact the Fairfax County Land Development Services before proceeding if the project is in Fairfax. Prince William and Arlington Counties have similar restrictions. Loudoun does not have RPAs but does have restrictions on land disturbance. (Source: Jim McGlone, VA Dept of Forestry)

Seeding a large area can turn into disaster, one gigantic weedy mess. Look at the meadows others have tried that just turned into a mass of Japanese stiltgrass. Who is going to spend the hours and hours necessary to do the weeding? An alternative strategy would be to start with a small area and expand over the years, or start with one or two species of grass and absolutely nothing else, get that established, then add the forba later. The fewer the species, the easier the weeding job for people who are not botanists. Spend the first year or so simply killing what is there already, letting more weeds sprout, then killing them as well, before doing any planting at all.

In a public setting, most people do better with a more traditional landscaping approach, using mulch initially between plants and not using seeds. For covering very large areas, there is a lot to be said for using shrub and trees with nice wide paths, plus some groundcover wherever you can afford to pay for enough plugs, and a manageable size pollinator garden somewhere in the mix. (Source: Margaret Fisher, Plant NOVA Natives)

Further Reading

Garden Revolution: How Our Landscapes Can Be a Source of Environmental Change, by Larry Weaner

Planting in a Post-Wild World: Designing Plant Communities for Resilient Landscapes, by Thomas Rainer and Claudia West

The Living Landscape: Designing for Beauty and Biodiversity in the Home Garden, by Rick Darke

Native groundcovers

Margaret Fisher, Plant NOVA Natives

Are you seeking a groundcover that is both beautiful and friendly to the ecosystem? Try looking beyond the old standbys to the new trend in gardening circles: native Virginia plants.

Bare ground in a garden is an invitation to weeds and erosion. The conventional landscaping solutions are either to pile on wood mulch or to plant an aggressive plant – such as English ivy, Japanese pachysandra, Vinca, spreading Liriope, or Yellow Archangel – then let it take over. The problem with those plants is that they take over more than just our gardens: they spread where they are not wanted by inexorably creeping along and by producing seeds that allow them to leap into our few remaining natural areas, where they crowd out the native plants and ruin the local ecosystem.

To prevent these unintended consequences, landscapers are now turning to plants that evolved locally, of which there are numerous examples that provide the “look” we are used to: a dense, low-growing monoculture for shade or part shade areas. Some are evergreen, others deciduous. A few have the additional feature of colorful spring flowers. Some can tolerate the bone-dry conditions under a tree; others prefer constant moisture. With the exception of Golden Ragwort (Packera aurea) and Common Violet (Viola sororia), none would be accused of being aggressive. Isn’t it nicer to have a beautiful groundcover that supports the ecosystem than to have a bare mulch garden? Details and photos can be found on the Plant NOVA Natives website.

2018 in review for Fairfax Master Naturalists

Our year in numbers, courtesy of Michelle Prysby, Director, Virginia Master Naturalist Program

Heres’s the flyer

2018 infographic of FMN accomplishments

Picking up paw paws and putting them in…delicious desserts

Bill Hafker

They’ve been called the American Custard Apple and the West Virginia banana, but Paw Paws  (Asimina trilob) are native to much of the eastern United States, typically growing in groups along streams and rivers. They have a large simple leaf and produce the largest fruit indigenous to the U.S. They also feature an unusual deep purple flower that gives off a fetid odor to attract beetles and carrion flies for pollination (the trees predate bees and butterflies as pollinators).

Paw paw trees. Photo: Bill Hafker

Fortunately, the fruit itself is very tasty to humans, too, and is the star ingredient in a dessert bread and pudding. Its flavor is often described as a cross between a banana and a mango. What follows is some useful lore for collecting paw paws and preparing these local treats.

When, where, and how to collect paw paws

In northern Virginia, paw paws ripen during late August and September. Because they spoil as quickly as they ripen, you will want to investigate their ripeness at the site from which you intend to collect them. Be sure that you have permission to collect them on the sites where you find them. Rules vary in the national, state, and county parks.

Collecting paw paws. Photo: Bill Hafker

Ripe paw paws will typically fall from the tree, and are best collected from the ground. Gently shaking a tree will also cause ripe fruit to fall to the ground. If you opt for fallen produce, check to make sure it is neither rotten nor full of scavenging ants. 

You can also buy them online at Integration Acres or Earthy Delights, and in some stores or farmers markets.

Cleaning paw paws and preparing the pulp 

Many recipes call for paw paw pulp in 1-cup units, so it is convenient to freeze it in one cup quantities that you can thaw and use as you wish. One cup of paw paw pulp equals approximately 3 medium mashed overripe bananas. 

To get started, remove the skin in any way that you find convenient (e.g., peel them with a knife or vegetable peeler, cut them open with a knife and scoop them with a spoon). Pulp adheres to the seeds, which are large enough to suck on, though you’ll want to avoid swallowing them. 

Using a spinner to process pulp off the seeds. Photo: Bill Hafker

It is time-consuming to prepare the pulp in bulk by trying to clean one paw paw at a time. I’ve found that the best way to process the pulp is to peel several fruits at one time and place them in the internal spinning part of a salad spinner that has been taken out of the rest of the spinner. Aggressively rubbing the fruit against the ribs of the spinner presses the pulp through the openings and into a bowl. You’ll want to make sure that you press the seeds firmly against the ribs to scrape off all of the pulp. When only relatively clean seeds remain, discard them and repeat the process with pulp-laden ones. 

Ready to bake?

Paw Paw Bread

You can replace bananas with paw paw pulp in your favorite banana bread recipe. Our family recipe calls for 1 cup of mashed paw paws, 1 cup of sugar, 1 egg, 1 ½ cups flour, ¼ cup melted butter, 1 tsp baking soda, and 1 tsp salt. You’ll want to mix all the ingredients until the batter is smooth, without over stirring. Pour the batter into a Teflon or buttered loaf pan. Bake 1 hour in a preheated oven at 325 degrees.

Paw Paw Pudding

This recipe from the New York Times is in the style of a bread pudding or English pudding (not Jello pudding).

Enjoy!

Your Camera as Eco-Warrior

Photo (c) Barbara J. Saffir

Margaret Fisher

We are surrounded by the ecosystem, even in our urban/suburban areas, but most of us never notice it. If we do see a plant, an insect or a bird, we lack the background to recognize it. Our experience of life is becoming more and more virtual as we live in a world of technology. Paradoxically, that very technology is now making it easy to find and identify the small residents of our yards. Getting to know our fellow beings makes us more likely to value and protect them.

The tool you need for this experience is a camera, even a basic cell phone camera. If you take a photo of an insect and enlarge it on your screen, you will be in for some big surprises. What you took to be a drab brown bug may turn out to be a wildly colorful and patterned creature, living its life and paying attention to your doings, even while you were unaware of it. The same discoveries are there to be made about birds, frogs, and all our other neighbors.

Better yet, if you upload photos of wild plants and animals to the free iNaturalist website or app, the artificial intelligence will suggest possible identifications, and then two actual human beings will review them to make the final determination. All this data is automatically entered into a worldwide global biodiversity database that is populated by contributions from citizen scientists such as yourself. All your observations will be saved and labelled in one place for your amusement. You can even create a project that collates all the observations from one location, such as your homeowners association, park, school, or faith community. Once you get hooked, you may find yourself trying to document all the life in your neighborhood. Here is an example from Huntley Meadows Park.

From April 26-29, iNaturalist invites everyone to join City Nature Challenge 2019, in which metropolitan areas participate in a friendly competition to see who can make the most observations. Events will be held all around the region, but you can also just take your camera outside and start documenting on your own. All observations made during that four day period will count.

What will become clear to you as you do this is that the more native plants you have, the more butterflies, bees, birds, and other wildlife you will find. You will see how preserving natural resources even in our built-up areas is critical to the survival of wildlife, and how the landscaping in your own yard can contribute to or degrade biodiversity, depending on your landscaping choices.

Watch Plant NOVA Native’s lovely one-minute video about iNaturalist and City Nature Challenge.

Events, trainings, ID parties, and videos for City Nature Challenge

Helpful video from Plant NOVA Natives:

Have you ever noticed that we are not alone in this world?

A calendar and map of local events courtesy of Capital Nature: Explore nature on your own and share what you find using iNaturalist  … or join others at an event.  All observations made from April 26 through April 29 will count!

Cheerily, cheer up: Colt Gregory on birding by ear

It’s impossible to miss the robins outside the window right now, but even if you missed Colt Gregory’s “Introduction to Birding by Ear,” at the March 18 FMN chapter meeting, it’s not too late to start understanding birdsong.

An Arlington Regional Master Naturalist and lifelong birder, Mr. Gregory entertained the crowd with reasons to learn the songs of local birds: they hide, for one thing, and it’s easier to hear them than to see them. Listening and parsing their music requires focus, which is good discipline for our fragmented attention. And, well, it’s fun to impress people. There’s more to it, of course, and he’s graciously shared his slides as a resource.

You’ll find a sound suggestion for what not to do: don’t play recorded calls outside because it confuses the birds and annoys other birders. But you’ll mostly find excellent resources for developing your skills. Mr. Gregory particularly recommends the CD Birding By Ear: A Guide to Eastern Bird-Song Identification, narration by Richard K. Walton and Robert W. Lawson: “This is an excellent way to learn songs and calls. Using an interesting approach, the CD places birds in general groups like whistlers, sing-songers, mimics, name-sayers, and high-pitchers.”

Birding by Ear, by Colt Gregory, ARMN, March 18, 2019

Thank you to Kit Sheffield for arranging the presentation. If you are interested in sharing your skills with our members or community, please contact Mr. Sheffield at vmnfairfax@gmail.com

Environmental Impacts of Road Salt

Article by Doug Britt, FMN and member, Reston Association’s Environmental Advisory Committee

Salt-based de-icing and anti-icing agents are routinely applied to roadways during and prior to winter storm events in Northern Virginia for the important purpose of maintaining public safety.  The primary agent used is sodium chloride (NaCl). The sodium, chloride, and other impurities in the salt eventually make their way into our environment through runoff from meltwater, as well as through splash and spray from vehicular traffic and wind. These processes can elevate sodium and chloride concentrations in the environment to harmful levels; although, sodium is not as prevalent a concern as chloride, owing to the greater solubility of the latter.

Road salt can contaminate drinking water resources, impair the ecology of lakes and streams, and harm local plants and animals. Salts also have negative impacts on infrastructure, vehicles, and other property. Corrosion from salts can increase the costs of maintenance, repair, and replacement of such infrastructure. Although there are a number of alternative de-icing agents available, sodium chloride as a brine solution appears to have the least negative environmental impact when considering the full life cycle of its production and application. Sodium chloride, nevertheless, can generate a host of environmental problems.

Water Quality Impacts

Contaminants from road salt enter water resources through storm drains, surface runoff, and infiltration into groundwater. In most parts of North America, chloride concentrations in freshwater surface waters are less than 120 mg/L. Chloride concentrations in Fairfax County surface waters have steadily increased for the past 25 years, consistent with the use of de-icing agents. Concentrations of chloride in surface waters are also correlated with the proportion of impervious surfaces in a watershed. Chloride also is seeping into groundwater throughout Northern Virginia where concentrations are steadily increasing with time. De-icing salts that seep into groundwater can be discharged as baseflow to local streams following a lag time of tens to hundreds of years.

Elevated chloride concentrations can lead to chemical stratification in lakes and ponds which impedes turnover and mixing of bottom and top waters – leading to oxygen deficiencies in deeper layers. High chloride levels are toxic to aquatic organisms such as fish and macroinvertebrates, and some aquatic plants. The presence of salt can also release toxic metals from the sediment. Various federal and Virginia state water quality standards and guidelines have been established to protect public health and the environment from the negative effects of sodium and chloride:

Soil Impacts

Through the process of cation exchange, the sodium ion replaces other soil cations such as calcium (Ca+), magnesium (Mg+), and potassium (K+) and changes soil permeability making soil more impervious, less stable, more acidic, and less fertile.

Pet Impacts

Ingestion of road salt directly (or from licking paws or drinking meltwater) can harm pet health in many ways, and in severe cases cause death. Salt exposure to a pet’s paws can also cause inflammation and sores that are slow to heal.

Wildlife Impacts

Birds may mistake salt crystals for seeds or grit. Consumption of even small quantities of salt can lead to death due to the extreme sensitivity of birds to salt. Some mammals (e.g., deer) are attracted to salt resulting in a higher risk for collisions with vehicles. Loss of salt sensitive vegetation can also impact wildlife habitat and create conditions favorable to non-native invasive species. Amphibians such as frogs, toads, and salamanders also are known to be sensitive to elevated salt levels given their very permeable skin, their physiological dependence on osmotic processes, and their early life stage in wetland habitats.

Roadside Vegetation Impacts

Impairment of roadside vegetation is often the most visible sign of salt damage to the environment. Salt impacts vegetation foliage via dehydration and can affect root health through osmotic stress. Salt also can disrupt nutrient uptake, seed germination, and plant development. Impacts to roadside vegetation can impair wildlife habitat, destroy buffer zones that capture and retain pollutants, and lower species diversity.

Infrastructure Impacts

Salt exposure impacts infrastructure, which can greatly increase required maintenance and replacement costs. Corrosion of roads, bridges, and sidewalks is a documented consequence of winter road activities, as is corrosion of vehicles. De-icing salts also can damage vehicle parking garages, which suffer the same corrosion damage as bridge decks. In addition to corrosion damage, de-icing agents can increase the frequency of freeze and thaw cycles that are deleterious to asphalt.

What is Being Done to Address this Issue Locally?

Recently The Izaack Walton League of America has initiated a Winter Salt Watch program, encouraging citizen scientists to monitor local streams before and after road salting activities. Several Reston residents, including myself, are now participating by monitoring Reston tributaries of Difficult Run (DR) and Sugarland Run (SR). As a baseline, I recorded chloride concentrations prior to the first 2019 winter storm at two of these sites. The results were 91 mg/L (SR) and 101 mg/L (DR), both being above average but within the normal range for North American streams. Chloride concentrations measured at these same locations subsequent to road salting associated with the first two snow/ice storms of 2019 exhibited more than a fourfold chloride increase (412 mg/L and 479 mg/L, respectively). Data from other Reston sampling sites are not yet available. If you would like to participate in the Winter Salt Watch program, you may do so directly through the Izaack Walton League of America (https://www.iwla.org/conservation/water/join-the-winter-salt-watch), or you may contact Will Peterson, Reston Association Watershed Manager (wpeterson@reston.org). Reston Association and has been monitoring the water quality in Reston’s four lakes since 1997. Although chloride concentrations are not directly measured, conductivity values are recorded multiple times each year. Conductivity is a measure of the electrical conductance of water and is positively correlated with salinity. The conductivity of all four Reston lakes is much greater since 2015 than their historic values.

The Virginia Department of Environmental Quality (VA DEQ) is currently developing a Salt Management Strategy (SaMS) planning process. The goal of the SaMS is to develop a comprehensive suite of management measures capable of achieving the chloride loads called for in the Accotink Creek chloride Total Maximum Daily Loads (TMDLs). TMDLs are developed to determine the total amount of a pollutant that a waterbody can handle without resulting in the impaired status of that waterbody. Although the TMDL was specific to the Accotink Creek watershed, the SaMS is intended to be applicable to the Northern Virginia region, including Reston, since winter application of salt products occurs similarly across all of our region. The final SaMS product will be a report outlining a comprehensive strategy to successfully reduce the impacts of salt products applied to manage snow and ice while maintaining high standards of public safety.

In 2018, the VA DEQ completed a report entitled “Salt Management Strategy: Environmental Impacts and Potential Economic Costs and Benefits of Improved Management Practices in Northern Virginia.” A literature review conducted as part of that report suggested that by using Best Management Practices (BMPs) to optimize de-icing agents and their application methods, it is possible to reduce both the costs and the negative impacts of de-icing operations without jeopardizing public safety. Next steps in the development of the SaMS include identifying traditional and non-traditional BMPs to achieve the SaMS goal, developing a water quality monitoring program to evaluate implementation effectiveness over time, developing a comprehensive education and outreach campaign, and developing a mechanism to track BMPs and salt use through a stakeholder-driven participatory process. The final report is expected in early 2020.

Meanwhile as individuals and business owners we should be cognizant of the potential environmental impacts associated with the application of de-icing agents. This understanding may help us better balance the twin goals of protecting public safety while minimizing environmental damage.

References

https://www.potomacriver.org/wp-content/uploads/2018/07/ICP18-3_Bencala.pdf
https://www.des.nh.gov/organization/divisions/water/wmb/was/salt-reduction-initiative/impacts.htm
https://www.iwla.org/conservation/water/join-the-winter-salt-watch
• Fay, L., D. Veneziano, A. Muthumani, X. Shi, A. Kroon, C. Falero, M. Janson, and S. Petersen. 2015. Benefit-cost of various winter maintenance strategies. Minnesota Department of Transportation No. CR 13-03.
• Laite, K., 2017, Annual Environmental Monitoring Program Lakes Anne, Thoreau, Audubon and Newport, Bright Pond and Butler Pond, Aquatic Environment Consultants, Inc.