Well Water - Shallow Wells in Riparian Zone Impacted by Surface Water Indicators and Horsehair Worms (Nematodes)

The KnowYourH2O Team has been contacted by residents in Western Pennsylvania regarding a problem with Nematodes in their Well Water.? With respect to the location of these wells, I am just going to say they are in the Allegheny River Basin located in the riparian zone for the Allegheny River and reportedly in wells that are 75 to < 100 feet deep. During my discussion with the well owners, the following seem to be the common threads:

1. They did not know how the wells were constructed.

2. They did not know if the wells were in the unconsolidated (sand and gravel aquifer) or bedrock.

3. The wells were not fitted with Sanitary Well Caps and the well casings were not 18 inches above grade.

4. The wells have never been evaluated to determine if the well is under the direct or indirect influence of surface water.? (For more info, visit our page Groundwater Under the Influence )

5. ?The wells appear to be located in the floodplain.

The Facts

It was suggested that the worms were “horsehair worms.” ?The following are some of the “Facts” related to “Horsehair Worms” that we have been able to compile.

1. Horsehair worms are long, measuring from several inches to over 14 inches.

2. The worms are quite thin, ranging from 1/25 inch to 1/16 inch wide (1 mm to 1.5 mm) and are uniform in diameter from front to back.

3. The worms vary in color from whitish to yellow/tan to brown/black.

4. Horsehair worms are found on the ground or on plants, especially near water.

5. Horsehair worm eggs range in size from 40 microns wide? to 50? microns long. Note: 40 microns is 0.001574803 inches ( Maybe visible to the naked eye).

6. The number of eggs produced per female is 27 million.

7. In general, the worms are considered non-pathogenic to humans and more pathogenic or disease-causing to: grasshoppers, crickets, beetles, katydids, caddisflies, millipedes, centipedes, spiders, crustaceans, leeches, snails, slugs, and other invertebrates (One reason to keep insects out of your well water).

8. “There are four stages in the life of a horsehair worm: the egg, the preparasitic larva that hatches from the egg, the parasitic larva that develops within an invertebrate (its host), and the free-living aquatic adult. The worms spend the winter in water. After mating in spring, the female worm deposits a string of eggs 12 to 24 inches long in the water. About three weeks to one month later, minute immature larvae hatch.”

9. “Domestic water supply systems should be filtered, chemically treated, and inspected for necessary repairs, especially when the homeowner discovers horsehair worms in wash water, bathtubs, or sinks. Moreover, it isn't unusual to find horsehair worms in the home in such places as shower stalls or toilets where crickets may die and worms emerge into the water. Prevent nuisance insects such as crickets, which are known hosts, from entering the home by caulking or sealing entryways.”

10. Case of Human Infection - “Two gordiid worms were collected in the vomit and excreta of an 80-year-old woman in November 2009 in Kyoto city, and in the mouth of a 1-year-old boy in December 2009 in Nara city, Japan, respectively. Both worms were males having bifurcated posterior ends and male gonads in cross sectional specimens. They were identified as Parachordodes sp. (Nematomorpha: Chordodidae) based on the characteristic morphologies of cross sections and areoles in the cuticle.”

11. “So yes, horsehair worms can end up in humans, but they do not gestate or mature in humans, nor do they burst out of humans. They do not migrate out of the digestive tract in humans, and, as the best medical knowledge at the time of writing this indicates, they do not produce any indirect symptoms, only the symptoms associated with something unpleasant in the digestive tract.”

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