Ecological assessment has begun on the health of Factory Brook. The water quality varies based on the density of invasive species, and level of human intervention / pollution. Throughout the brook there is no aquatic life under the water aside from a few species of plants and algae - no fish, frogs, or submerged insects.
The upper leg of the stream emerges from a natural spring, which is immediately is contaminated with feces of unknown origin, potentially from a sewer issue on Burnside or from animal activity. The amount of contamination (which indicates if it is hazardous) is unknown. High levels of nutrients are detected, indicating non-point pollution - potentially fertilizer runoff from playing fields and nearby yards, automobile pollution from route 9, and/or issues in the sewer lines.
Invasive growth impedes the brook's flow, leading to the water being shallow, stagnant, with an unpleasant odor. Minimal aquatic life is seen, consisting only of algae and a few insects. This area used to contain numerous native frogs and duckweed, which leads to the conclusion that the spring has been greatly degraded by human activity - with reports indicating the frogs died following the insecticide spraying to prevent West Nile, and the plant life being upended by sediment and earth moving during the construction of the Burke playing fields.
As the stream flows into the old duck pond the water quality seems to be dramatically improved, with high levels of dissolved oxygen and greatly increased aquatic life. This area warrants increased attention to determine if it may harbor a richer ecosystem upon restoration.
Although the duck pond is encouraging, this quickly deteriorates once the brook exits the Burke property. Life is completely interrupted through pollution, invasive species, barriers such as perched culverts and dams, and hardened banks. The water flowing out into the Hudson in its final leg is completely devoid of life.
Moreover, this unhealthy water is considered a flood risk along route 9 - a common issue in waterways which fail to have sufficient natural riparian areas to accept natural water fluctuations. Climate change is predicted to exacerbate flooding in the future
The following tests were done with off-the-shelf kits by non-professionals, please take the results with a grain of salt.
Description: Coliform bacteria (such as e-coli) normally live in the digestive tracts of animals, presence of this bacteria in a waterway indicate potential contamination by sewage or feces, and possible vector for contagious illness.
Result: Positive
Interpretation: This water is contaminated with feces of either human or animal origin. The sewer line on Burnside drive may be the source. Until the coliform levels are tested, we can't know whether this water is safe for recreation (most natural waterways contain some amount of animal feces, which is why it is boiled or treated before considered safe for drinking).
Description: Animals require oxygen to live. In aquatic environments the oxygen is dissolved in the water, typically being mixed in through natural churn (this is why bubblers are required in fish tanks). Low oxygen levels lead to inhospitable or deadly environments for fish and other aquatic life.
Result: 5.5mg/L at the mouth of the brook, >9mg/L exiting the Burke Estate
Interpretation: The head of the stream is inhospitable but not deadly to aquatic life, which is unsurprising given that the water appears stagnant. A steep waterfall near the duck pond provides significant churn and thus oxygenation to the water. Upon exiting the Burke the waterway has sufficient oxygen to support abundant fish populations.
Description: Although at very high levels Nitrates can harm human health, much lower levels can still throw ecosystems out of balance. Algae and plants depend on Nitrates to grow, which is why it is a common component in garden fertilizers. Plants and algae can grow out of control when nitrate levels are high(known as Eutrophication). As these overpopulated plants proceed through their life cycle and eventually die, their decomposition depletes water of oxygen.
Result: 2 PPM
Interpretation: This is well within the safe range of Nitrates.
Description: Phosphate is another driver of eutrophication of waterways. Like Nitrates, it is a necessary component of plant growth and thus an overabundance will lead to plant overgrowth and eventual oxygen depletion.
Result: 0.3 mg/L
Interpretation: The EPA recommends no more than 0.1 mg/L phosphate for streams which do not empty into reservoirs. This number is 3x that recommendation, and thus warrants concern.
The water emerges at a spring located near Burnside and Broadway. The water is clear and cold with minimal insect life. Decaying organic matter can be seen in the water, and an unpleasant odor can be detected. Approximately 5% of the water surface contains algae, no other aquatic plants are seen. Footprints of deer and raccoons are seen in the mud which indicates it is a local drinking water source for mammalian life. The water flows into a dense stand of invasive common reed, where it becomes impassible to humans but supports diverse and dense bird populations for bathing, drinking, and roosting.
Downstream the water flows through a partially submerged metal culvert, which has been overgrown with invasive multiflora rose, porcelain berry, and common reed. The water is shallow, stagnant, dark, with a dense layer of sediment at the bottom. There is a significant increase of insect life including flies, bees, water skaters, midges, and occasional dragonflies. No aquatic plants are detected. A thin oily sheen can be seen on the surface.
After passing through more common reed, the stream branches out into multiple channels in an area shaded by willows, oaks, tulip trees, and silver maples. Mosses, ferns, and flowering plants can be seen growing on the saturated muddy banks. No shrubs are present. Non-native Watercress is abundant, and a small amount of native water-starwort. The water is cold and clear, and quite shallow. The flow rate is much increased. It again flows out into dense stands of common reed which are largely impassible. Different small herds of deer (around 3 herds, 1-4 individuals at a time) are often seen resting here. Insect life is less than the previous area, but continues to contain midges and water skaters.
Impassible stands of multiflora rose, porcelain berry, common reed, and japanese honeysuckle, bar access to a significant portion of the stream. Tree coverage is minimal. The edges are bordered by dense growths of poison ivy. There is no break in the growth indicating open water, thus it can be assumed that various small stagnant flows pass amongst the vegetation at this point.
The stream emerges into two legs - one running alongside the collapsed stone wall along Broadway, and the other running diagonally with surveyors sticks marking its path. The Broadway stream is cold and clear, and densely bordered by native jewelweed and goldenrod, and various invasive / non-native plants. The water is significantly populated with water-starwort. The diagonal stream runs directly through a monospecific stand of Common Reed. It is shallow, with a fine dense sediment full of dead common reed. No aquatic plants are seen.
The two streams merge under a collapsed ornamental bridge into a stone lined channel where foam is briefly present, before dropping approximately five feet into a marble tunnel which feeds a small stone-lined pond shaded by trees. When viewing the pond, moderate water-starwort can be seen. The water has no smell and is clear and cold. Occasionally mallard ducks can be seen, and significant songbird activity is present - both bathing and drinking. Large numbers of water skaters and midges can be seen. Subjectively this appears to be the healthiest and most natural portion of the waterway.
After passing over a partially collapsed stone dam, the water flows along natural banks before being diverted into another stone channel running along the eastern side of route 9. This deep narrow channel passes alongside several houses before entering a tunnel, merging with a storm drain set into the road.
The brook emerges on the western portion of route 9, north of Washington. The waterway flows through a deep chasm full of large stones. Significant invasive plants growth is detected on the banks. Once again the path is channeled underground.
A concrete perched culvert carries the water to its next exposed leg. The water drops approximately one foot into a deep chasm full of large rocks, shaded by large trees. Significant garbage and debris can be seen, including tires, car batteries, and plastic containers. Only invasive plants are seen in the undergrowth, no plant or insect life is seen in the water.
After passing through numerous rapids and pools formed by rocks, the water flows into an old stone tunnel under the aqueduct. The stream at this point is approximately 1 inch deep and 1 foot wide, with very rapid flow. Algae can be seen growing on the stone floor of the tunnel. The water is cold and has no scent. It emerges into another rocky shaded chasm, where it merges with another stream and flows over several shallow artificial waterfalls and stone channels before flowing into the Cropsey pond.
The cropsey pond is privately owned, and contains invasive carp and non-native vegetation. The water appears clear, and is highly attractive to native geese and ducks which frequent the area. This is the final open segment of the brook, it passes over an artificial dam and into a 4' concrete pipe which runs beneath the commuter lot. A small grating allows a last look at the water, which appears to be very clear, shallow, and rapidly moving. Several manholes top the pipe further downstream, where the water is audible but not visible. The pipe then passes under the metro north line and is inaccessible to the public, but is known to be channeled to the Hudson through a submerged pipe beneath the old factory site.
Factory Brook is an example of a unique stream ecosytem which numerous species depend on. Many ocean fish such as the American Eel and Brook Trout depend on safe cold headwaters to spawn, accessed by swimming up ocean-bound brackish rivers to their small tributary sources. Meanwhile amphibians seek out even smaller streams inaccessible to fish in order to lay their vulnerable egg-clutches. Both amphibians and fish are predated upon by predators such as Herons and Muskrats. With sufficient restoration, some of these species can be brought back to their native home.
Global warming is predicted to bring significant flooding and storms, with flooding and storm surge maps showing inundation into the commuter parking lot and along route 9. Through a combination of riparian restoration, selective daylighting, and improved culverts / channels, these issues could be greatly mitigated or resolved.
The brook passes through several access points to the village - Route 9, the Aqueduct, Warburton, and the Metro north. Each of these points provides an opportunity to pause and admire the beauty of the waterway. This beautification not only is valuable to residents, it also encourages travelers to visit Hastings as a destination.
Historians believe that the most western portion of factory brook was of great cultural significant to the Lenape people who originally resided in Hastings - with numerous artifacts found along the banks. Restoration of the Brook would give an opportunity to intentionally make space for indigenous history.
As the water originates in a spring within town borders, the quality of the water could be greatly improved purely through localized efforts. With enough attention the water could be returned to high enough quality to allow swimming and other recreation activities, without the PCB concerns which haunt the Hudson beaches.