Engineering on the Trail

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Photo: The Potomac Canal at Great Falls Park, NPS by A. Toure

Article and photos by FMN Stephen Tzikas, except as noted

There are a lot of “roadside engineering” ruins found along roads and trails.  I like to visit them when I travel to nearby states. Typically these engineering ruins include iron furnaces, canals, and grist mills, but may include other interesting relics of industrial archaeology. We have such places in Fairfax County.

The ruins of Matildaville

At Great Falls Park, the geology of the area gave rise to engineering associations. River processes involve many engineering principles related to fluid mechanics. Rivers, too, offer opportunities for the application of geology for engineering works such as transport and power generation. Here in Great Falls Park, a complex of ruins are associated with a canal.  The ruins of Matildaville are located along one of the trails. It was a town associated with a canal built next to the Potomac River.  The ruins date from 1790, when the town was planned as an industrial community which would support canal operations. The town started as a staging and headquarters area for the construction of a canal. The town included a forge, a gristmill, a store, storage buildings, the superintendent’s house, a market, a sawmill, an ice house, worker barracks, boarding houses, a few smaller homes, and an inn.  Construction of the canal took 17 years, becoming operational in 1802. However, the Patowmack Company succumbed in 1828, turning over its assets and liabilities to the newly formed Chesapeake and Ohio Canal Company, whose canal ruins are also in the nearby area.  Alas the town did not survive the closing of the canal in 1830.  Eventually all canals were made obsolete by the railroad.

A Potomac Canal Lock at Great Falls Park

The stone ruins of an upstream portion of the Potomac Canal at Great Falls Park usually does not have water flowing in it, but on rare occasions it does.  Canal ruins that are usually seen, such at Great Falls Park, are of locks.  A boat going down stream entered a lock at its upper end.  At the lower end a gate kept the water in.  The upper gate was then closed.  Values in the lower gate were opened to lower the water level to the next lock downstream.  The lower gate was opened and the boat proceeded to the next lock.  For boats going upstream, the procedure was reversed.  If a location had a mountain lake such as the Morris Canal in New Jersey, these engineering marvels could even literally cross over a mountain!

 

The Clifton Institute Presents – Warbler Song Bootcamp, April 11th

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Image: The Clifton Institute Warbler Song Bootcamp

Friday April 11th, 2025
6:00 pm – 7:00 pm
This event is Free! But if you are able, there is a suggested donation of $10.00

Virtual Event
Registration is REQUIRED.

*This is a virtual event. Registration will close at noon on April 10 to make sure everyone gets the Zoom link. If you have not received a Zoom link by that time please email Eleanor at [email protected]. If you would like to register at that time, you can email Eleanor, but she may not see your email in time. *

Brush up on your warbler songs just before the migrants arrive in droves. You will listen to the songs of each of the migratory warblers that pass through our region in spring, while looking at spectrograms to help visual learners identify differences in similar songs. You will also briefly discuss habitats where breeding warblers can be found in our area and cover a handful of other migrants such as vireos and thrushes. This workshop will be of interest to birdwatchers of all skill levels. It will definitely be more fun than listening to a warbler song CD in your car! This event will take place over Zoom. A Zoom link will be emailed to participants shortly before the event.

Cost: Free! But if you are able, there is a suggested donation of $10. All proceeds from The Clifton Institute programs go directly to funding their education programs, restoration work, and research projects. Thank you for your support!

Age: All ages.

 

Alliance Afternoon: Matt Felperin’s Birdathon Warbler Bootcamp, March 23rd

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Photo Matt Felperin -Yellow-throated Warbler

Sunday, March 23, 2025
2:30 PM – 4:30 PM

National Wildlife Federation
11100 Wildlife Center Drive
Ste. 100RestonUnited States

This event is FREE and registration is not required, but those who register will receive an email reminder.

Join the quarterly live Audubon Afternoon at the National Wildlife Federation, 11100 Wildlife Center Drive in Reston.

There will be an informal gathering starting at 2:30 pm so you have an opportunity to reconnect with everyone. You are welcome to bring any food and drink to share with everyone during the informal portion of the program. At 3:00 pm, the Board President will present the revised bylaws for member approval. The formal program will begin at 3:15pm, when guest speaker Matt Felperin will give a Warbler Bootcamp in preparation for spring migration. He will also speak about Birdathon, the Audubon Spring fundraiser, and how to get your team set up. All are welcome to attend, participation in Birdathon is encouraged but not required.

After the talk, from 4:00 – 4:30 pm, stick around to speak with board members and staff about how you can get more involved! Volunteers are needed for a new bird strike monitoring program, spring outreach tabling, purple martin monitoring, invasive removal and more.

More about the speaker: Matt Felperin is a DC area local, raised in Takoma Park, MD. He is the Roving Naturalist with NOVA Parks, the regional park system of Northern Virginia. Matt has always been drawn to nature, and has been sharing his findings with anyone within earshot since his days as a small child looking for salamanders and crayfish in nearby Sligo Creek. He truly treasures the Chesapeake Bay and has enjoyed field work and naturalist programs in several types of habitat within the Chesapeake Watershed, and credits working under naturalist Greg Kearns for truly sparking his love of birds. As the NOVA Parks Roving Naturalist, Matt leads environmental education and recreation programs such as bird walks and kayak tours for the public. He views his wildlife photography work as one of the most useful tools to connect people with nature.

Open to the general public, all are welcome!

This event is FREE and registration is not required, but those who register will receive an email reminder.

Backyard Bird ID Workshop, March 20th

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Photo: Cerulean Warbler by Matt Felperin

Thursday, March 20, 2025
7:00 PM – 8:00 PM

Virtual

Free – RSVP now and start birding!

Sign-up for this exciting backyard bird identification workshop, where you will dive into the fascinating world of local birds and seasonal visitors! Whether you’re watching from your window, patio, or garden, you’ll gain the confidence to identify and appreciate the birds around you.

During this workshop, we’ll cover:

  • Common backyard bird species you’re likely to see year-round

  • Migratory warblers that might pass through your yard this Spring

  • Essential birding tools—from field guides to apps and binoculars

  • How to use Merlin to identify unfamiliar birds

  • How to use e-bird to report birds you observe

  • Tips for creating a team and participating in Birdathon

This is also a great opportunity for Wildlife Sanctuary Program participants to brush up on how to identify the Sanctuary Species that visit their yards. You need to document 10 sanctuary species to get your certification! Board Member Betsy Martin will join workshop to speak about that program and how you can make your yards friendlier to birds.

March Green Breakfast, In Person, March 8th

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Image: Fairfax County

Saturday, March 8, 2025
9 am
Ornery Public House, 3950 University Dr., #106 Fairfax VA

Register here.

Join Sara Girello with Fairfax County Government’s Office of Environmental and Energy Coordination (OEEC) for the first in-person Northern Virginia Soil and Water Conservation District Green Breakfast since 2019! Come learn more about climate action in Fairfax County and the county’s work to “Sustain Fairfax”. They will highlight the county’s climate plans, programs, and progress and what you can do to save money, reduce your emissions, build resilience, and help our community.

This Green Breakfast is IN-PERSON and includes actual breakfast! Please register here so NVSWCD can let the restaurant know how many people they need to plan for. The cost will be $15, payable in cash at the door.

If you have questions, please email [email protected]

Did you miss their last Green Breakfast? They’ve got you covered! View the recording of our January 2025 Green Breakfast with Carolyn Wilder of the Wildlife Rescue League here.

Clean Water and Native Plants

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Article by Plant NOVA Natives; Image: https://jamesriverconsortium.org

If your property contains a stream, pond, or any sort of wetland, whether its flow is permanent or intermittent in nature, this article is especially for you! Anyone can directly enhance water quality, and in turn benefit the health of the animal, plant, and human communities that depend upon it, by using native plants to fill the “riparian buffer” adjacent to a water feature. The word “riparian” comes from a Latin word meaning “bank.” A riparian buffer protects the wetland from runoff from developed areas, including turfRegrass lawns.

If the riparian buffer already contains natural vegetation, you should first control any invasive plants found there.You should also avoid adding any new species, native or otherwise, that will disturb the existing plant community. You may need a waiver from your County to remove existing vegetation and to plant new plants within 100 feet of a stream, shore, or wetland. Maps of these “Resource Protection Areas” can be found here. If the area is currently landscaped or mowed, you may be able to add native plants without a waiver, but you should still check with your county or municipal government.

To figure out if the plants that are present are native or invasive, you can use a free app such as iNaturalist or a subscription-based app such as PictureThis to help you with the identification. You can also invite a volunteer from the Northern Virginia Bird Alliance Wildlife Sanctuary Program to walk the site with you.

Healthy riparian buffers with native plants are beautiful to see and fun to explore. They support a wide diversity of life and create peaceful and inviting landscapes that draw us in to enjoy and connect with the nature they support.

Riparian buffers are also the natural defenders of stream banks. They help stabilize the soil and control soil erosion. This is due to their capacity to slow down and absorb stormwater runoff that would otherwise erode the banks of streams and rivers and fill the Chesapeake Bay with excessive silt. Due to riparian buffer degradation and excessive runoff across Northern Virginia, a massive quantity of silt from our streams and rivers now reaches the Chesapeake where it clogs the gills of wildlife, smothers eggs, buries aquatic insect habitats, and interferes with the production of oxygen by aquatic plants. Anything we do that successfully holds soil will benefit the Bay. Riparian buffers also act as filters that trap pollutants. This protects aquatic life from harmful contaminants and keeps them out of our water supply. Native trees provide the leaves that feed aquatic insects, and their shade lowers the water temperatures, making the environment more hospitable for life. As the earth warms, planting and protecting native plants on riparian borders will become increasingly urgent.

Ideally a riparian buffer should be at least 100 feet wide, but don’t let that discourage you, as a buffer of any size is helpful. Try to pick combinations of native plants that would naturally occur along waterways in your region. This will increase the odds of creating a balanced healthy habitat that continues to grow and thrive. Please refer to the resources on the Plant NOVA Natives website to help you select your plants.

Riparian buffers formed naturally on undisturbed land, holding soil, cooling water, filtering pollutants, and supporting life. It is humans who have disturbed them. Our work now is to take a moment to pause and wonder at the interdependence of land, water, native plants, and animals. Regardless of the other forces at work to degrade our environment, we still have the power to rebuild essential habitats on the lands we control.

Upcoming Fairfax County Stream Monitoring Opportunities

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Photo: J. Quinn

The Northern Virginia Soil and Water Conservation District (NVSWCD) monitors several streams throughout Fairfax County during their scheduled stream monitoring workshops throughout the year. These workshops engage volunteers in collecting data, with scheduled monitoring sessions at least twice a year at each location.

NVSWCD trains volunteers to assess ecological conditions in streams based on the absence/presence of benthic macroinvertebrates (aquatic bugs and other critters). Training includes field workshops and mentoring by experienced monitors, no prior experience required!

Volunteers can assist at different levels of commitment. You may choose to participate in one or a few NVSWCD public stream monitoring workshops, or you may become a certified stream monitor to adopt your chosen stream and commit to monitoring it at least twice a year.

There are three shifts scheduled thus far –

  • March 11, from 10am-1pm at Sugarland Run in Herndon
  • March 16, from 9am-12pm at Pohick Creek in Springfield
  • March 20, from 3-6pm at Difficult Run in Great Falls

Minimum age: 12  (All volunteers under 18 years of age must be accompanied by an adult.)

To sign up, please log in to Volunteer Fairfax and search for stream monitoring.

To learn more about NVSWCD and their activities, see their page here: https://www.fairfaxcounty.gov/soil-water-conservation/volunteer-stream-monitoring

Contact Ashley Palmer for more information at 703-324-1423 or [email protected].

Jerry Nissley

Volunteer Opportunities at Hidden Oaks Nature Center

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Photo: By FMN Jerry Nissley, Hidden Oaks Nature Center

The Hidden Oaks Nature Center staff are looking for volunteers to fill these two positions.

Volunteer on Duty – Weekdays and Sundays

If you love nature and enjoy talking to people, consider volunteering at Hidden Oaks Nature Center’s front desk. You will welcome visitors, orient them to the park, answer questions, and check in program participants. This is an opportunity to learn about the natural resources of the county and share your knowledge.

Weekdays:  Shifts are 9am-1pm or 1pm-5pm

Sundays:  Shifts are 12pm-5pm, every other week

 Program Aides

Assist Hidden Oaks with teaching the public, especially kids, and have fun doing it.  Included is learning all about the local environment and nature during our programs, while on field trips, or at tabling events.  This is a wonderful opportunity for anyone with a passion for the outdoors and a drive to help instill your passion on a new generation.  Opportunities may be intermittent and based on events and registration.

If interested, please contact the Hidden Oaks volunteer coordinator at [email protected].  Thank you!

 

 

Virtual Symposium on Innovative Park Stewardship, March 25th

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Photo by Kit Sheffield, The floodplain at Riverbend Park gets a different mix of species from the upland areas.

Tuesday, March 25, 2025
11:00am – 1:30pm

Virtual

Webinar is free but registration is required.

Discover how communities across Northern Virginia are transforming their parks through powerful community-government collaborations.

This program is presented by Northern Virginia Bird Alliance and co-sponsored by Earth Sangha and Plant Nova Natives.

Discover how communities across Northern Virginia are transforming their parks through powerful community-government collaborations. Four distinguished park stewardship leaders will share their success stories, practical insights, and answer your questions about creating effective partnership models. Our speakers include representatives from Friends of Mason Neck, Loudoun Wildlife Conservancy, Upton Hills Regional Park, and Riverbend Park.

This virtual symposium is a component of our Stretch Our Parks initiative, dedicated to enhancing the ecological value of Northern Virginia’s parks for birds and other wildlife. Following the success of our Habitat Restoration and Expansion Symposium last October, we developed this program in direct response to participants’ requests for deeper insights into park stewardship models.

Why Attend?

  • Learn proven strategies for public/private partnerships
  • Engage directly with experienced park stewardship leaders
  • Network with fellow park advocates and environmental professionals
  • Gain practical tools to implement in your community

Detergents and Stream Environments

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Feature photo:  Stream Bubbles along the Turquoise (Glade) Trail stream in Reston. Bubbles and soap films are made of a thin layer of water, sandwiched between two layers of soap molecules.

Article and photos by FMN Stephen Tzikas

During your outdoor activities, you may have seen soap suds in a trail stream.  While there is some environmental concern about them, their science is interesting.

My first professional exposure to detergents was with my first career project in 1985, at an environmental closure of the General Aniline & Film (GAF) plant in Linden, NJ.  I had the task, among other things, of testing, classifying, and preparing various detergents and surfactants for proper disposal.  The company, founded in 1886, had its origins as the German IG Farben firm whose assets were seized as enemy property in 1941.  When I see suds in a stream, I always remember the project at GAF.

Detergents are used for many purposes, but they can easily get

Surface Tension at the Turquoise Trail stream in Reston. Detergents lower the surface tension of the water, making it hard for aquatic insects like water striders to float on the surface.  They can leave fish and other critters starved for air. Detergent binds up oxygen to form bubbles.

into freshwater ecosystems.  Detergents are organic compounds, which have both polar and non-polar characteristics. There are two kinds of detergents: phosphate detergents and surfactant detergents. Detergents that contain phosphates are caustic, and surfactant detergents are toxic. Surfactant detergents are used to enhance wetting, foaming, dispersing and emulsifying properties. Phosphate detergents are used to soften hard water and help suspend dirt in water. Detergents, including biodegradable ones, can be poisonous to aquatic life. They can destroy the external mucus layers that protect the fish from bacteria and parasites. Most fish will die when detergent concentrations approach 15 parts per million, and concentrations as low as 5 ppm will kill fish eggs. Surfactant detergents can affect the breeding ability of aquatic organisms. Detergents also lower the surface tension of the water, which impacts some aquatic life.  Phosphate detergents can lead to freshwater algal blooms that release toxins and deplete oxygen.

Soaps and detergents are made from long molecules that contain a head and a tail. The diagram below represents a surfactant molecule. The head of the molecule is attracted to water (hydrophilic) and the tail is attracted to grease and dirt (hydrophobic). When the detergent molecules meet grease on clothes, the tails are drawn into the grease but the heads still remain in the water. The attractive forces between the head groups and the water are so strong that the grease is lifted away. The blob of grease is now surrounded by detergent molecules and washed away. The detergent molecules also help to make the washing process more effective by reducing the surface tension of the water.

How Detergents Work (Snapshot excerpted by author from https://molview.org with a search on sodium o-dodecylbenzenesulfonate.) The long chain of the sodium o-dodecylbenzene-sulfonate molecule is “grease-loving” while the cyclic part is “water-loving.”

Emerging stream concerns include another type of foamy substance.  This is a group of manufactured compounds known as per- and polyfluoroalkyl substances (PFAS). PFAS have broad uses in commercial products such as food packaging, nonstick coatings, and firefighting foam. Conventional wastewater treatment plants do not effectively remove PFAS. The PFAS concentration lifetime advisory is 70ng/L for perfluorooctanoate (PFOA).

In Fairfax County, the storm drainage system is separate from the sanitary sewer system. Storm drains convey stormwater runoff directly to local streams. Car wash water may contain oils, greases, detergents and other materials that pollute water and harm wildlife that live in streams. In Fairfax County, commercial car washes must be equipped with water recycling systems and discharged to the sanitary sewer system.  Individual residential car washing is exempt from this regulation. You can help by washing cars in an area away from storm drains. Use the minimum amount of detergent necessary, and use products that are biodegradable, phosphate-free, water-based, and pH neutral.