Water Resources

Surface Water Quality

Several parameters are used to assess water quality and track human-induced impacts. Many of the data reported here are medians for selected water quality variables. The source of the majority of the data below is a study by the Dutchess County Environmental Management Council [9]. Similar information, although spanning a different time period, is available for the Tenmile River at Wassaic and there have been many studies at specific sites conducted by the Hudson River National Estuarine Research Reserve, The Cary Institute of Ecosystem Studies, and faculty at Vassar College.

Chloride

Chloride is the negatively charged portion of a variety of salts including sodium chloride (NaCl), calcium chloride (CaCl2 ), and magnesium chloride (MgCl2 ). Chloride enters surface water from several sources including geologic formations containing chloride, agricultural runoff, industrial wastewater, effluent from wastewater treatment plants, and a major contribution from salting of roads. Excess chloride can contaminate freshwater streams and lakes, negatively affecting aquatic communities.

While there are no set standards for chloride in fresh surface waters, studies have shown impacts on aquatic communities at various concentrations. Chloride concentrations of approximately 120 mg/L should be protective of freshwater organisms for short-term exposure; concentrations less than 35 mg/L are likely protective during long-term exposures [10]. Approximately 5 percent of species would experience effects from chronic exposure to concentrations of chloride of 210 mg/L, while 10 percent of species would be affected at concentrations of 240 mg/L [10]. According to the United States Environmental Protection Agency, biota on average should not be affected if the four-day average concentration of chloride does not exceed 230 mg/L more than once every three years [11].

Biotic impacts would be minimal if the one-hour average chloride concentration did not exceed 860 mg/L more than once every three years [3]. In a 2006 study of Dutchess County tributaries to the Hudson River [9], chloride concentrations were below levels set by the EPA for acute (860 mg/L) and chronic (230) exposure [12], but it is worth noting that Environment Canada recommends maintaining chronic chloride concentrations at or below 35 mg/L [10]. The annual median chloride concentration for Dutchess County streams ranged from less than 2 to 127 mg/L (Table 1). It is difficult to evaluate this chronic threshold because the data collected during this study were not collected frequently enough to develop chronic exposure recommendations. It is notable, however, that all the watershed median concentrations were higher than Environment Canada’s chronic threshold except the highly forested watersheds of Mount Beacon which fell well below 35 mg/L.

The highest median annual chloride concentrations were in the suburbanized watersheds of the Casperkill, and two streams designated HR 99 and HR 98. Although one would expect that the highest median concentrations would be in urban streams like the Fall Kill in Poughkeepsie and the Fishkill in Beacon, their annual median chloride concentrations were not nearly as high as in these suburban watersheds. The Fall Kill shows effects of road salting with extremely high chloride concentrations in January and much lower concentrations in the summer months. However, the Casperkill, HR 99, HR 98, and the Fishkill Creek contained high chloride concentrations throughout 2004. On average for all the watersheds, summer/fall chloride concentrations were higher than winter/spring concentrations. This could be an indication of a chronic source of chloride such as sewage, or perhaps road salt is being stored in the sediment and released throughout the year following rain events [13].

Phosphorus

Phosphorus is a nutrient essential to plant growth. In aquatic ecosystems phosphorus occurs primarily in the form of organic phosphorus, which is bound in plant and animal tissue and unavailable for plant uptake. Plants are able to assimilate phosphorus in the form of phosphate (PO4 3-) from the surrounding water and convert it to organic phosphorus. In freshwater ecosystems phosphate tends to be the least available nutrient, causing it to be the limiting factor for plant growth. Because of this, small additions of phosphate to surface waters can result in large amounts of plant growth and eutrophication.

The most likely sources of phosphate inputs include animal wastes, human wastes, fertilizer, detergents, disturbed land, road salts (anticaking agent), and stormwater runoff. In general, any concentration over 0.05 mg/L of phosphate will likely have an impact on surface waters [14]. However, in many waterbodies, concentrations of phosphate as low as 0.01 mg/L can have a significant impact. In order to control eutrophication, the USEPA recommended limiting phosphate concentrations to 0.05 mg/L in waters that drain to lakes, ponds and reservoirs, and 0.1 mg/L in free flowing rivers and streams [15]. New York has an existing ambient water quality guidance value of .02 mg/l for phosphorous [16].

The median phosphate concentration of Dutchess County’s streams ranged from 0.01 mg/L in several streams to 0.09 mg/L in the Sawkill (Table 5.3).

In-stream median annual phosphate concentrations were similar to the threshold value in the literature of 0.010 mg/L for relatively undeveloped watersheds in the United States. Indian Kill, Crum Elbow Creek, Maritje Kill, Wappinger Creek, HR 98, and Wade’s Brook all fell within this threshold. The three watersheds that stood out with high phosphate concentrations were Stony Creek, Saw Kill, and HR 99. In Stony Creek and the Saw Kill, concentrations were highest in July during the lowest flow period. This is an indication of a chronic source of phosphate that becomes more evident as water levels drop and the phosphate becomes more concentrated. The source may have been the wastewater treatment plants that were upstream of the sampling sites. However, HR 99 contained consistently high phosphate concentrations throughout the year. This could suggest another source such as failed septic systems or fertilizers, or be an indication that the stream is just too small to effectively dilute the wastewater effluents it receives.

Nitrogen

Nitrogen is found in various forms in ecosystems including organic forms such as proteins and amino acids, nitrate (NO3 - ), nitrite (NO2 - ), and ammonium (NH4 + ). The majority of nitrogen on earth is in its gas form (N2 ), which makes up approximately 80 percent of our atmosphere. It is converted into organic forms by certain terrestrial plants (legumes), nitrogen-fixing bacteria, lightning, and microbes in the water and soil. Nitrate, the most mobile form of nitrogen, can be assimilated by vegetation to make protein, leached into groundwater or surface water, or converted to nitrogen gas in the process of denitrification [17]. Nitrite, ammonia, and ammonium are intermediate forms of nitrogen in aquatic systems and are quickly removed from the system by being converted to either nitrate or nitrogen gas [14]. Ammonium is released into the system during decomposition or when animals excrete their wastes; through the process of nitrification, ammonium is oxidized to nitrate by bacteria.

Major sources of nitrate in streams include municipal and industrial wastewater discharges and agricultural and urban runoff. Atmospheric deposition of nitrogen from automobile exhaust, power plants, and industrial emissions is also a source [18].

Excess nitrate can accelerate the eutrophication of surface waters and can present a human health concern in drinking water. Nitrate concentrations of 44 mg/L (equivalent to 10 mg/L nitrate-nitrogen for EPA and NYSDOH standards) or higher have the potential to cause methemoglobinemia, or “blue baby” disease in children [19]. High concentrations of nitrate in water can serve as an indicator of sewage, fertilizers, or other contaminants. Although the human health standard for nitrate consumption has little correlation with stream health, high levels of nitrate in both surface and groundwater typically indicate widespread nonpoint source pollution.

Due to land uses and atmospheric deposition, concentrations of in-stream nitrate typical of undeveloped watersheds rarely occur in the Hudson Valley. The annual median nitrate concentration of Dutchess County’s streams ranged from 0.02 (HR90) to 6.75 mg/L (Saw Kill) (Table 1). With the exception of Wades Brook and HR-90, median nitrate concentrations in Dutchess County streams were all above the threshold value of 0.087 mg/L for streams in the United States in relatively undeveloped watersheds [20]. Gordon’s Brook, Wade’s Brook, and HR 90 all contained relatively low concentrations of nitrate, chloride, and phosphate because their watersheds mostly drain the heavily forested Mount Beacon. These watersheds could be considered as a reference baseline for comparison with other local watersheds.

In northern Dutchess County, nitrate concentrations were highest in Stony Creek and the Saw Kill in July 2004. These high concentrations occurred during periods of low flow, indicating a chronic source of nitrate that becomes diluted during higher flows. The source could be treated sewage effluent since both sampling sites were downstream of wastewater treatment plants, and/or septic system effluent. Watersheds in the Poughkeepsie-Fishkill region had the highest median annual nitrate concentrations, and the highest individual reading was in the Fishkill Creek in July 2004. The Fall Kill, located in one of the most urbanized areas of Dutchess County (City of Poughkeepsie), contained relatively low nitrate concentrations, likely because a majority of the watershed above the sampling site was sewered and several ponds and wetlands located upstream of the sewered section trap pollutants.

Conductivity

Conductivity measures the ability of water to carry an electric current and is determined by bedrock geology and the addition of salts from several human activities. Studies of inland freshwaters indicated that streams supporting good mixed fisheries had a conductivity range of 150 to 500 µmhos/cm [21] , and that a benchmark of 300 µmhos/cm is appropriate for invertebrate genera [22] Annual median conductivity for Dutchess County streams ranged from near 50 µmhos/cm (at HR90 and Wade’s Brook) to nearly 1000 µmhos/cm (at HR 99, Table 1).

Table 1: Annual median nitrate, phosphate, chloride and conductivity summary for 2004 (collected January through November, bimonthly) and the water quality impact criteria from literature values (expanded upon in introduction).

Other Chemical and Physical Parameters

The pH of water is important to monitor because most species of aquatic organisms require a pH in the range of 6.5 to 8.0; variance outside of this range can stress or kill organisms. Due to the acidity of rainfall in the northeastern United States, maintaining this range is of concern. Average pH of rainfall in New York ranges from 4.0 to 4.5. Dutchess County contains large amounts of calcium carbonate bedrock, which provides a buffer for acidic inputs and acts to raise the alkalinity and hardness of water. However, this buffering capacity can diminish over time with geologic weathering.

Sulfate (SO4 2-) can occur naturally as a result of decomposition of organic matter, water passing through rock or soil containing gypsum and other common minerals, or atmospheric deposition. It can be also be found in municipal sewer treatment plant discharges, fertilized agricultural runoff, or industrial discharges. The combustion of fossil fuels releases large amounts of sulfur to the atmosphere, where it is oxidized to sulfate and may fall in precipitation or be deposited as gas. Sulfate is highly mobile and often ends up in streams and lakes; therefore, monitoring levels of sulfate in surface waters may provide a means of tracking impacts of fossil fuel combustion. The median concentration of sulfate across all streams in the 2006 Hudson River tributaries study was 17.3 mg/L; the highest concentration was found in the lower Fishkill at 52.2 mg/L. Several streams with long-term water quality monitoring have shown declines in SO4 concentrations almost certainly due to lowered sulfur emissions following the Clean Air Act Amendments.

Turbidity is an optical measurement of the light-scattering at 90o caused by particles suspended in water. Turbidity is measured in arbitrary “nephelometric turbidity units” (NTUs) by a “nephelometer.” The higher the NTU value, the lower the water clarity and the murkier the appearance. Total suspended solids are a measure of suspended solids concentration, expressed as a mass per volume (mg/L) obtained by physically separating the liquid and solid phases by filtration. There is no single, fixed relationship between turbidity and total suspended solids. Turbidity can be influenced not only by the amount of particles in suspension but also by the shape and size of the particles. Increased turbidity can be caused by soil erosion, waste discharge, urban runoff, bottom feeders such as carp, and algal growth. Turbid waters become warmer as suspended particles absorb heat from sunlight, causing oxygen levels to fall. Photosynthesis also decreases with less light, resulting in even lower oxygen levels. Finally, the suspended material in turbid water can clog fish gills, reduce growth rates, decrease resistance to disease, and prevent egg and larval development. In general, turbidity tends to be low in Dutchess County streams although high-frequency sampling that would detect turbidity spikes related to storm events has generally not been carried out.

Water temperature is one of the most important variables in aquatic ecology. Temperature affects the movement of molecules, fluid dynamics, and metabolic rates of organisms as well as a host of other processes. In addition to having its own potential “toxic” effect (such as when the temperature is too high), temperature affects the solubility and toxicity of other parameters. Generally, the solubility of solids increases with increasing temperature, while the solubility of gases (including dissolved oxygen) decreases with higher temperatures.

In densely wooded areas where the majority of the streambed is shaded, heat transferred from air and groundwater inputs drives in-stream temperature dynamics. However, in areas that aren’t shaded, the water temperatures can rise much more quickly due to direct exposure to the sun’s radiation. Water temperatures exceeding 77 degrees Fahrenheit cannot be tolerated by brook trout; they prefer water temperatures less than 68 degrees Fahrenheit [23].

Determining whether a stream has good or bad water quality depends largely upon the end user. Water quality in Dutchess County can vary from stream to stream and mile to mile within the same stream. However, as indicated by the “snapshot” offered above, water quality in Dutchess County tends to be good, with a few exceptions. Degradation tends to not come from a direct point but results from slower changes that occur over time with land use changes that increase impervious surface cover and decrease the amount of water that infiltrates into the ground. The impacts of these activities on our water resources reverberate throughout the system. They are most obvious during flood events that cause the loss of property and infrastructure, but effects are also evident during low flow periods when the stream is over-wide and shallow, unable to support a vibrant coldwater fishery in affected segments.

Water Quality Standards

The federal and New York State governments have developed water quality and purity standards to monitor and protect waterbodies. The Federal Water Pollution Control Act of 1972, as amended (and subsequently called the Clean Water Act), imposes strict standards on water quality and pollutant levels. Part 701 of the 1974 New York Environmental Conservation Laws (6 NYCRR) outlines the water quality and priority classifications and standards for New York State waterbodies.

All waters in New York State are given a class and standard designation based on present quality and best usage for that water body [24]. In the case of streams and rivers, the classifications are assigned to specific segments of a watercourse. The New York State DEC stream classification system includes the following designations:

• AA / Drinking (after disinfection), Bathing and Fishing
• AA / Drinking (after disinfection and approved treatment), Bathing and Fishing
• B / Bathing and Fishing
• Class / Fishing- Propagation and Survival
• D / Fishing- Survival

Additional designations of “T” or “TS” can be added to Class A, B, or C stream if a water body has sufficient amounts of dissolved oxygen to support trout (T) and/or trout spawning (TS). Water bodies that are designated as “C (T)” or higher (e.g., “C (TS)”, “B”, or “A”) are collectively referred to as “protected streams,” and are subject to additional regulations and require a State permit for disturbance of the bed or banks.

The New York State DEC also applies standards that correspond to these classifications when reviewing stream disturbance or pollutant discharge permit applications. This is to prevent the existing water quality from deteriorating. Some of these standards are described in numerical form whereas others are in narrative form. The details of these standards can be found in New York Codes, Rules, and Regulations, Title 6, Department of Environmental Conservation, Chapter X, Division of Water, Part 703, Surface Water and Groundwater Quality Standards and Groundwater Effluent Limitations.

Most of the streams, rivers, lakes, and ponds within Dutchess County are Class B, C, or D. Some of the more significant AA and A streams and lakes are listed below:

• Clove Creek - at Fishkill water supply –
• Crum Elbow Creek and tributaries - upstream of Hyde Park Fire and Water District intake –
• Ellis Pond - Fishkill Creek - at Beacon water supply –
• Gardiner Hollow Brook - at Green Haven State Prison water supply –
• Green Mountain Lake –
• Hiller Brook and tributaries - at Pawling Village water supply. –
• Indian Kill - at Staatsburg water supply –
• Long-Pond – upstream end of H-101-18-11 and 0.6 mile northwest of Schultzville.
• Pawling Reservoir –
• Silver Lake – Located at upstream end of H-101-18-13 and 1.0 mile northwest of Bullshead
• Swamp River - at Harlem Valley Hospital water supply –
• Ten Mile River, wells, stream, and tributaries - at Dover Plains auxiliary water supply –
• Tributaries of Cargill Reservoir

A complete list of the classifications for Dutchess County waterbodies and stream segments can be found at Department of Environmental Conservation Regulations, Chapter X, Part 857 for the Wappinger Creek Basin and at Part 862 for the other drainages entering the Hudson River.

Waterbody classifications affect, but do not totally restrict, land uses and discharges along waterways. If wastes are treated to satisfy the appropriate standards, they can be discharged under permit (see below). The standards protect the rights and property values of landowners along water courses by protecting them from water pollution. Stream classifications are periodically revised by the New York State Department of Environmental Conservation. Public hearings are an integral part of the reclassification process.

Periodically, the DEC publishes the Priority Waterbodies List (PWL), which includes a list of water bodies that do not meet their designated “best use” classification. A data sheet that describes the conditions, causes, and sources of water quality degradation for each of the respective listings is included in the PWL. The PWL is used by the DEC and other agencies as a primary resource for water resources management and funding. You can access the classification of your stream on the Dutchess Environmental Mapper.

The PWL is included within the Waterbody Inventory (WI), a comprehensive inventory of all the waterbodies in New York State that is maintained by the DEC. The purpose of the WI/PWL is to characterize the extent to which designated water uses are being supported, to identify waterbodies that have been impaired, and to track efforts to restore impaired waterbodies to their designated uses. The WI is part of an overall program known at the Comprehensive Assessment Strategy (CAS) conducted through an ongoing series of rotating basin surveys. The DEC has assigned all of the waterbodies in NYS to one of 17 designated drainage basins. The waterbodies of Dutchess County, including those that drain to the Housatonic River, are part of the Lower Hudson River Basin.

Each year two to three of the drainage basins are reassessed, allowing all 17 to be reevaluated every five years. The reassessments are conducted over a two-year period and involve an examination of data on biomonitoring, water and sediment chemistry, and sediment toxicity as well as any data generated by site- or problem-specific monitoring activities. The primary question that is addressed in each review is whether the waterbodies support their designated uses such as public bathing, drinking water, support of aquatic life, etc. Based on the data review by DEC staff and personnel from other cooperating agencies, the waterbodies (or segments thereof) are classified into one of six categories: impaired waters, waters with minor impacts, threatened waterbodies, waterbodies with impacts needing verification, waterbodies with no known impacts, and unassessed waterbodies. Waterbodies that are classified in one of the first three categories are assigned to the Priority Waterbodies List (PWL).

According to the 2008 Lower Hudson River Basin WI/PWL Report, most waterbodies in Dutchess County have not been assessed. For those waterbodies that were assessed, impairment was documented at Hillside Lake, Wappingers Lake, and segments of the Fall Kill and its tributaries. Minor impacts were observed at lower Fishkill Creek, Sylvan Lake, and segments of the Casperkill Creek, the Landsman Kill, the Rhinebeck Kill, and their respective tributaries.

Discharges of stormwater and wastewater are regulated in New York State under the State Pollutant Discharge Elimination System (SPDES). The original intent of this legislation was to control point sources of pollution such as industrial outfalls and discharges from publicly owned wastewater treatment plants. Operators of these facilities are required to obtain permits that specify the maximum quantity of wastewater to be discharged into the waters of New York State. The law also imposes upper limits for specific categories of pollutants. When the federal CWA was amended in 1987, a set of mandated requirements known as Phase I was added to address discharges from additional types of industrial activities, medium and large Municipal Separate Storm Sewer Systems (MS4s) and construction activity disturbing more than five acres of soil. These sources were also required to obtain SPDES permits.

Under the more recent Phase II of the CWA, efforts were intensified to reduce pollutant loading from construction sites of one acre or larger and from municipal stormwater conveyance systems. Municipalities that met certain criteria of population size (>50,000) and population density (>1000 people per square mile) were automatically designated as MS4s. As of January 2010, these communities are required to develop and fully implement a Stormwater Pollution Prevention Plan in order to receive a general permit allowing them to discharge stormwater into the waters of New York State. The communities in Dutchess County that were automatically designated as MS4s are listed as follows: Beacon (C), Beekman (T), East Fishkill (T), Fishkill (V) and (T), Hyde Park (T), LaGrange (T), Pleasant Valley (T), Poughkeepsie (C) and (T), Union Vale (T), Wappinger (T), Wappingers Falls (V), where T, C, and V refer to town, city, and village respectively. Because they have lands that fall within the New York City Department of Environmental Protection East of Hudson watershed, additional parts of Pawling (T) and (V), Beekman (T), and East Fishkill (T) are also required to comply with the Phase II regulations for MS4s.