Bronx River Research Articles

Combined Impact of Inland and Coastal Floods: Mapping Knowledge Base for Development of Planning Strategies

AbstractConcurrent incidence of heavy rainfall events and coastal storm surges can cause damages of exponential proportion to the coastal habitants and infrastructures. Super Storm Sandy and hurricane Irene were wake up calls that the floodplains and evacuation zones in New York City need major revision. Federal and State emergency agencies have been working on revising the appropriate maps and spatial tools for planning and management purposes. This paper presents an integrated scheme for floodplain delineation in coastal areas, considering the combined effect of inland and coastal flooding. The proposed scheme is applied to the Bronx River watershed in the Bronx section of New York City. Consideration of inland and coastal flooding is provided by developing a conceptual rainfall-runoff model and a sea level simulation model. Climate change has intensified the intensity and frequency of extreme rainfall events and storm surges in the region. In order to evaluate climate change impacts on floodplain, proj...

Analysis of the Effects of Climate Change on Urban Storm Water Runoff Using Statistically Downscaled Precipitation Data and a Change Factor Approach

AbstractIn urban areas, there is concern that storm water runoff and flooding may be intensified because of the effect of climate change on precipitation amounts, intensities, and frequencies. Studies are needed to help storm water managers to plan and design effective adaptation and mitigation measures. This paper presents a study of the effects of climate change on urban storm water runoff in the Bronx River watershed in New York City. To show the effects of climate change on future precipitation, projections by 134 general circulation models (GCMs) from the fifth phase of the coupled model intercomparison project (CMIP5) are used. A new change factor method is proposed to select minimum, maximum, and mean daily precipitation scenarios for a future time period of 2030–2059. Because of the importance of short duration for extreme storm events, the daily precipitation is disaggregated to hourly increments. The U.S. Environmental Protection Agency storm water management model (SWMM) is used to model the hy...

Low-Impact Development Practices to Mitigate Climate Change Effects on Urban Stormwater Runoff: Case Study of New York City

AbstractUrban stormwater runoff management systems are usually designed to meet performance standards based on historical climate data, which are assumed to be stationary. Based on the evidence from climate change impact studies, in the near future, stormwater management systems, within the built environment, may need to meet performance expectations under climatic conditions different from historical climate. Considering the impacts of climate change on rainfall intensities and stormwater runoff peak flow and volumes, and in turn the effectiveness of mitigation, practices for urban stormwater management are desirable. This paper presents the results of a climate change impact study on urban stormwater runoff in the Bronx River watershed, New York City. Considering the impacts of climate change on watershed runoff, the potential for low-impact development (LID) controls to mitigate the impacts was investigated. Stormwater runoff and LID controls were modeled using the U.S. EPA Storm Water Management Model...

Field scale evaluation of seaweed aquaculture as a nutrient bioextraction strategy in Long Island Sound and the Bronx River Estuary

article i nfo Nutrient bioextraction using GracilariatikvahiaeMcLachlanwas tested attwosites: one off Fairfield,CT (LIS),and the other at the mouth of the Bronx River Estuary (BRE), during the summer and fall of 2011 and 2012. The es- timates of nitrogen (N) removal by Gracilaria over a 90-day growing season were up to 28 and 94 kg N ha �1 at theLISandBREsites,respectively.InJuly2012,Gracilariagrewupto16.5%day �1 atBREand 4.8% day �1 attheLIS site. Tissue N contents at the same periods were 3.7% (BRE) and 1.5% (LIS), respectively. These results demon- strate rapid assimilation of nutrients fueling the growth of new Gracilaria tissue at the BRE site, while nutrients appeared to limit growth at the LIS site during the summer months. The estimated C removal by Gracilaria at the BRE and LIS sites were up to 300 kg ha �1 (LIS) and 727 kg ha �1 (BRE), respectively. The potential economic values of N and C sequestration for the period examined in this study were as high as $311 (LIS) and $940 ha �1

Evidence for intraspecific endocrine disruption of Geukensia demissa (Atlantic ribbed mussel) in an urban watershed

Populations undergo physiological adaptations in response to environmental stressors. Our 5-year bio-monitoring study of the Bronx River Estuary demonstrates comparatively low dissolved oxygen concentrations in this urbanized watershed. Additionally, our current results establish altered hormonal levels, resulting from endocrine disruption, in Geukensia demissa (Atlantic ribbed mussel) from the Bronx River Estuary. No studies have yet investigated a correlation between low dissolved oxygen and endocrine disruption in field-collected bivalves. Testosterone, estradiol, and progesterone levels were collected from male and female mussels in the oxygen depleted Bronx River and well-oxygenated Greenwich Cove. Bronx River mussels exhibited higher testosterone levels and lower estradiol levels than Greenwich Cove mussels. The resulting abnormal hormonal ratio seems to indicate that environmental conditions in the Bronx River facilitate an allosteric inhibition of the cytochrome P450 aromatase enzyme, which aids conversion of testosterone to estradiol. Low progesterone levels suggest that Bronx River mussels are experiencing a delay in sexual maturation, and morphometric data show a stalling of shell and tissue growth. To confirm that the mussels collected from both sites are the same species, the universal mitochondrial cytochrome c oxidase subunit I gene was analyzed, through DNA barcoding. Minimal sequential heterogeneity confirmed the mussels are the same species. Such findings suggest intraspecific divergence in various endocrine processes, resulting from environmentally induced stress.

Con Edison's Success in Reducing Risk: Applying Real-World Lessons Learned to Broaden Spill Planning and Response Programs and Build Personnel Competencies

ABSTRACT Con Edison's service territory covers more than 1,000 miles of inland and coastal shoreline in one of the most heavily regulated and scrutinized areas of the Unites States: New York City. In November 2009, the company experienced a catastrophic failure of a large transformer at a high-voltage electric substation, resulting in approximately 200 gallons of dielectric oil impacting the Bronx River. While the volume of oil was relatively small, the duration of the cleanup lasted nearly one month with costs of approximately $1.75 million, plus a nearly $1 million compliance order issued by New York State for violation of state regulations. Following this event, and through a study of all historical spill incidents, it was clear that the primary risk of spills to the environment came from the more than 30 million gallons of oil contained in the company's high-voltage transformers and oil-filled electric transmission and distribution system, which were not covered by existing Facility Response Plans developed as part of implementing OPA 90. Given these results, the company sought to refine existing spill response program elements to further reduce risks and enhance environmental stewardship. Using the existing Spill Management Team (SMT) model in the OPA 90 program, a company-wide SMT approach was created to better prepare for and reduce the risks associated with potential spills from all company sources. The team consists of more than 50 personnel from the various business units of the company, providing direct access to a wide spectrum of skill-sets and specialties. In addition, the company has developed Oil Spill Contingency Plans (OSCP)—also covered under OPA 90—with detailed response tactics for over 300 locations. On the heels of the program implementation, a large spill of dielectric oil from an underground high-voltage electric distribution line resulted in more than 2,000 gallons impacting the Hutchinson River. While the impact to the waterway was greater than in the 2009 event, the response duration was only 6 days with clean-up costs just over $300,000 with no state issued compliance order, a significant improvement. This result was due, in large part, to implementation of the OSCP and SMT programs. Through these experiences, the many benefits of establishing a company-wide SMT and the OSCP's were realized, including developing spill response and Incident Command System expertise, refined coordination, and improved cost management. These efforts have significantly reduced the company's spill risk exposure by improving response capabilities.

Trace element concentration and speciation in selected urban soils in New York City

A long history of urbanization and industrialization has affected trace elements in New York City (NYC) soils. Selected NYC pedons were analyzed by aqua regia microwave digestion and sequential chemical extraction as follows: water soluble (WS); exchangeable (EX); specifically sorbed/carbonate bound (SS/CAR); oxide-bound (OX); organic/sulfide bound (OM/S). Soils showed a range in properties (e.g., pH3.9 to 7.4). Sum of total extractable (SUMTE) trace elements was higher in NYC parks compared to Bronx River watershed sites. NYC surface horizons showed higher total extractable (TE) levels compared to US non-anthropogenic soils. TE levels increased over 10year in some of the relatively undisturbed and mostly wooded park sites. Surface horizons of park sites with long-term anthropogenic inputs showed elevated TE levels vs. subsurface horizons. Conversely, some Bronx River watershed soils showed increased concentrations with depth, reflective of their formation in a thick mantle of construction debris increasing with depth and intermingled with anthrotransported soil materials. Short-range variability was evident in primary pedons and satellite samples (e.g., Pb 253 ± 143mg/kg). Long-range variability was indicated by PbTE (348 versus 156mg/kg) and HgTE (1 versus 0.3mg/kg) concentrations varying several-fold in the same soil but in different geographic locations. Relative predominance of fractions: RES (37%) > SS/CAR (22%) > OX (20%) > OM/S (10%) > EX (7%) > WS (4%). WS and EX fractions were greatest for Hg (7%) and Cd (14%), respectively. RES was predominant fraction for Co, Cr, Ni, and Zn (41 to 51%); SS/CAR for Cd and Pb (40 and 63%); OM/S for Cu and Hg (36 and 37%); and OX for As (59%).

Using Life Cycle Assessment to Evaluate Green and Grey Combined Sewer Overflow Control Strategies

SummaryDecentralized approaches to managing urban stormwater are gaining increased attention within the contexts of urban sustainability, climate change adaptation, and as a means of reducing combined sewer overflows (CSOs). This study applied a life cycle assessment (LCA) to comparing the environmental efficiency of three means of equivalently reducing CSOs to the Bronx River (Bronx, NY, USA). Strategy 1 featured decentralized green infrastructure technologies, while “grey” strategies 2 and 3 detained, and detained and treated, respectively, excess flows at the end of pipe. We estimated greenhouse gas emissions (in metric tons of carbon dioxide equivalents [t CO2‐eq]) over the construction, operation, and maintenance phases, including energy consumed at the wastewater treatment plant (WWTP), carbon sequestered, and shading provided by vegetation (in the case of the green approach) over a 50‐year analysis period. The study area comprised the entire drainage area contributing to New York State permitted CSO discharge points associated with the Hunts Point WWTP. The analysis was performed using a hybrid of process and economic input‐output (EIO) LCA methods. The decentralized green strategy outperformed the two grey strategies in terms of this set of environmental metrics. The net emissions of the green strategy over 50 years was 19,000 t CO2‐eq, whereas the grey strategies emitted 85,000 t CO2‐eq (detention) and 400,000 t CO2‐eq (detention and treatment). These results were significantly influenced by the emissions associated with the operation and maintenance activities required for strategies 2 and 3, and the carbon sequestered and shading provided by the vegetation in strategy 1, and suggest that watershed managers who seek to reduce CSOs and reduce carbon footprints would opt for the green approach.

Sculpting Solutions: Art–Science Collaborations in Sustainability

Crisscrossed by highways, dotted with brownfields, and largely cut off from the river that named it, the Bronx in New York City remains, despite everything, a picture of human resilience. Beginning...

Estimation of Phosphorus Bioavailability in the Water Column of the Bronx River, New York

Phosphorus (P) is a primary limiting nutrient in rivers and streams, and excessive P results in eutrophication of freshwater systems, in turn, excessive algal growth/toxic algal blooms, oxygen depletion, and water quality degradation. This study analyzed P pool, and hydrolysis of organic P (OP) by native phosphatases (NPase) in the water samples collected in the Bronx River. The soluble reactive P (SRP) of most of the sites’ water collected in 2006 and 2007 were higher (average 67 μg?L–1 and 68 μg?L–1, respectively) than the US Environmental Protection Agency’s (EPA) standard of 15 μg?L–1. The SRP% (SRP/TP%) average was 27% in 2006, much lower than in 2007 of SRP% average 83%. The OP% (OP/TP%) average was 73% in 2006, which was much higher than the OP% in 2007 (which was only 17%). The SRP concentrations and distributions (%), and the total P (TP) concentrations were in substantial amounts compared with other rivers. The NPase hydrolyzed OP % was up to 100% in 2006 and 2007 water samples. The average of NPase% was 59% in 2006 and 73% in 2007. The NPase average concentrations were 348 μg?L–1 in 2006, and 175 μg?L–1 in 2007. The NPase hydrolyzed up to 100% of OP% in the Bronx River water samples at 37?C, indicating a potential threat of eutrophication of freshwater systems as the global rise in temperature may continue to occur.

Spatial variability in nutrient concentration and biofilm nutrient limitation in an urban watershed

Nutrient enrichment threatens river ecosystem health in urban watersheds, but the influence of urbanization on spatial variation in nutrient concentrations and nutrient limitation of biofilm activity are infrequently measured simultaneously. In summer 2009, we used synoptic sampling to measure spatial patterns of nitrate (NO3 −), ammonium (NH4 +), and soluble reactive phosphorus (SRP) concentration, flux, and instantaneous yield throughout the Bronx River watershed within New York City and adjacent suburbs. We also quantified biofilm response to addition of NO3 −, phosphate (PO4 3−), and NO3 − + PO4 3− on organic and inorganic surfaces in the river mainstem and tributaries. Longitudinal variation in NO3 − was low and related to impervious surface cover across sub-watersheds, but spatial variation in NH4 + and SRP was higher and unrelated to sub-watershed land-use. Biofilm respiration on organic surfaces was frequently limited by PO4 3− or NO3 − + PO4 3−, while primary production on organic and inorganic surfaces was nutrient-limited at just one site. Infrequent NO3 − limitation and low spatial variability of NO3 − throughout the watershed suggested saturation of biological N demand. For P, both higher biological demand and point-sources contributed to greater spatial variability. Finally, a comparison of our data to synoptic studies of forested, temperate watersheds showed lower spatial variation of N and P in urban watersheds. Reduced spatial variation in nutrients as a result of biological saturation may represent an overlooked effect of urbanization on watershed ecology, and may influence urban stream biota and downstream environments.

Autumn foliage reflected in Bronx River at Harsdale, New York

Autumn foliage reflected in Bronx River at Harsdale, New York

Assessments of Potential Spatial-temporal Variations in Phosphorus Distribution and Fractionation in River Bed Sediments

Sediment characteristics influence the distribution and bioavailability of phosphorus (P) in river sediments. In this study, we analyzed different P fractions in the sediments of the Bronx River, New York City, NY, using sequential extraction. The results showed that the average P pool rank order was HCl-P > NaOH-P > NaHCO 3 -P > residue-P, and their relative proportions were 3.7: 2.0:1.4: 1 in sediments collected in 2006, while HCl-P > NaOH-P > residue-P > NaHCO 3 -P, with their relative proportions of 27.8:6.2:2.7:1 in the sediments obtained in 2007. The strong correlation between microbial P and organic P (OP), along with the changes in microbial P over time indicate that most of the OP in the river bed sediments is potentially bioavailable. The sediment transport, deposition, assimilation, the exchange of P between sediments and water columns, the land use changes, raw sewer discharge, gas spill, construction, fertilizer application, etc., as well as the hydro-climatic changes could result in the spatial and temporal variations in P bioavailability in the river bed sediments. The estimations of P pools and their bioavailability in river bed sediments could help determine the spatial and temporal variations in P transport and impacts of land use on water quality, in turn, help regulate P in the river's watershed.

Land Use Impact on Bioavailable Phosphorus in the Bronx River, New York

Various forms of phosphorus (P) could become bioavailable such as from desorption, dissolution and enzymatic hydrolysis. Potential bioavailable P estimation is critical to minimize eutrophication in freshwater systems. Thus, this study was conducted to predict potential bioavailable P in the water columns and sediments and their relations with enzymatic hydrolysis, and estimate impacts of land use and anthropogenic activities on P bioavailability, P transport and water quality in the Bronx River, New York, USA. In sediment samples collected in 2006, total P (TP), total inor-ganic P (IP), total organic P (OP) and bioavailable P (BAP) were in highest concentrations in sites located at Bronx River Valley upstream in Westchester (site 2), Troublesome Brook (TB, site 4), Sprain Brook (SB, site 7b) and Bronx River estuary near Sound View Park (site 14) respectively. Also, phosphodiesterase and native phosphatases (PDEase and NPase) hydrolyzed distinguishingly high amounts of OP or enzymatically hydrolysable P (EHP) in samples from sites 4, 7b, 10 (New York Botanical Garden) and 14. Microbial P was in negative values (caused by different bacteria and microorganisms could not be paralyzed by chloroform), and the most negative concentrations were appeared at sties 4 and 14. Spatial comparisons among different locations showed distinguished characteristics in tributaries and estuary. In sediments collected in 2007, TP, BAP and IP were in highest concentrations at sites 7-SB, 11-Bronx Zoo, 12-East Tremont Ave Bridge where fresh and saline water meets, 13-estuary facing Hunts Point Waste Water Treatment Plant (HP WWTP) and 14-estuary along Sound View Park. Besides, PDEase-P highest concentrations ap-peared at sties 7, 13 and 11, NPase-P concentrations were highest at 7 and 11. Microbial P was highest at sties 11 and 14. Spatial variations showed that higher P content and more intense enzymatic hydrolysis in silty clay finer sediments at site 7, 11 and 13. Temporal variations between the two years’ data showed land use and other anthropogenic factors’ impacts on P transport in river and deposit in sediments. Analysis of the river water samples showed that average soluble reactive P (SRP, 67 μg.l-1) in 2006 and SRP (68μg.l-1) in 2007 both were greater than background P concentration in most natural water (42 μg.l-1).

The Once and Future New York: Historic Preservation and the Modern City. By Randall Mason. (Minneapolis: University of Minnesota Press, 2009. xxxiv, 307 pp. Cloth, $84.00, ISBN 978-0-8166-5603-5. Paper, $27.95, ISBN 978-0-8166-5604-2.)

Historians usually place the origin of New York City's historic preservation movement in 1960s attempts to save Pennsylvania Station. Randall Mason's book demonstrates that the movement actually started as part of Progressivism in the 1890s, when preservationists identified, commemorated, and protected selected sites. Those sites formed a “memory infrastructure” of buildings, places, and public art that preservationists believed created a collective memory that would educate the public in history and patriotic virtues. Mason identifies the American Scenic and Historic Preservation Society (ashps) as one of the leading heritage conservation institutions and examines its representative sites. The many attempts to redesign New York's City Hall Park were part of a robust debate about symbolism, real estate, urban design, transportation, an expanding city government, and politics. The plan for the Bronx River Parkway addressed the ecology, economy, appearance, selected history, and social character of the Bronx River valley to create a park and a road.

Enzymatic hydrolysis of organic phosphorus in river bed sediments

Enzymatic hydrolysis of phosphorus (P) in bed sediments is an important process that maintains bioavailable P in the river systems. The P bioavailability is the criterion for assessing the eutrophication potential in rivers and streams. The objective of this research was to determine potential bioavailability of organic P (OP) in the Bronx River bed sediments using native phosphatases (NPase) and phosphodiesterase (PDEase) hydrolysis. The bed sediments collected in summer 2006 and 2007 were incubated at 37 °C for 6 h at pH 7.5 with NPase. The results showed that NPase hydrolyzed a substantial amount of OP (up to 76%) under favorable temperature and pH, indicating OP could be hydrolyzed under increased temperature, and in turn increase in P availability in the river. Similarly, the resulting form sediments incubated with PDEase at 37 °C and pH 8.8 showed that up to 82% of OP could be hydrolyzed. Strong correlations between percentage of OP hydrolyzed by PDEase and organic matter (OM) were observed for sediments collected in 2006 ( r = 0.745; p ≤ 0.01) and 2007 ( r = 0.724; p ≤ 0.01), indicating PDEase hydrolysable P is mainly associated with OM. It is indicative that local hydro-climatic changes such as temperature increase and pH variations could hydrolyze a substantial amount of OP and increase bioavailable P in the water column, resulting in a potential threat to the river ecosystems.

Documenting New York's Bronx River Parkway, USA

New York's Bronx River Parkway was a seminal development in the history of the modern motorway. Conceived in 1906 and completed in 1925, the parkway was the first public project to provide a large-scale demonstration of the essential components of modern motorway design: strict limitations on access and egress, grade-separated interchanges, flowing horizontal and vertical curvature geared toward safe and pleasurable high-speed travel, and a broad publically owned right-of-way for better control of the roadside environment and greater flexibility in alignment and location. The Bronx River Parkway was embraced by the motoring public, hailed by contemporary design professionals, and celebrated by subsequent historians. In recognition of the parkway's significance, the Historic American Engineering Record (HAER) conducted a multi-disciplinary documentation project in 2001. HAER produced large-format photographs, a detailed historical report, and measured and interpretive drawings depicting construction details, development processes, and design concepts. The project was part of a larger effort to document historic American roadways including National Park Service park roads and parkways, Columbia River Highway, Merritt Parkway, Taconic State Parkway, and the Arroyo Seco Parkway/Pasadena Freeway. This documentation can serve as a valuable model for future efforts to document and interpret twentieth century motorways and other civil engineering resources.

Phosphorus sorption characteristics of the Bronx River bed sediments

Phosphorus (P) is a major nutrient for plant growth, and it is often the primary limiting nutrient in freshwater ecosystems controlling algal blooms. The Bronx River of New York City, New York, USA includes freshwater and coastal water systems. The water quality of both fresh and saline water is lower than the standard levels designated by New York State, and classified as Class B and Class I waters, respectively. Algal blooms and oxygen depletion within the river have degraded the water quality, endangered fishing, and limited recreational use. The internal loading of P, an important bioavailability indicator in the Bronx River, is determined by the sorption processes, i.e., cycling of P between solid and liquid phases. The objectives of this study were to understand how P sorption characteristics affect the internal loading of P and the conditions that might give rise to a flux of P from sediment to the water column, and to estimate the effects of physicochemical properties of the sediments on P sorption parameters. Bed sediments were collected from 15 sites along the Bronx River, from the origin in Westchester Davis Brook, Kensico Dam through the Bronx to the Sound View Park estuary. Phosphorus sorption maximum (Smax) were significantly correlated with oxalate–extractable iron (Ox–Fe) and aluminum (Ox–Al), acid-extractable calcium (HCl–Ca) and magnesium (HCl–Mg), and total organic matter (OM), suggesting that not only metal ions affected P sorption characteristics, but OM also influenced the P sorption processes. This study also showed that originally sorbed P (S0) was significantly correlated with Ox–Fe, Ox–Al, HCl–Mg, and OM. The extremely high values of the percentage of sorbed P retained in sediments (>98% for all sites except the two estuary sites: site 13 of 88% and site 14 of 92%) suggest that a large flux of P to the water column from the sediments could potentially occur under changing hydro-climatic conditions, such as the changes in pH, ionic strength and redox conditions, which may, in turn, exacerbate eutrophic conditions and subsequent algal blooms.

Identification of organic phosphorus compounds in the Bronx River bed sediments by phosphorus-31 nuclear magnetic resonance spectroscopy

Sediment characteristics influence the distribution and bioavailability of phosphorus (P) in rivers and lakes. The objectives of this study were to identify P compounds in sediments collected from 15 sites along the Bronx River to get insights on nutrient transport for management of highly variable and modified ecosystems such as the Bronx River. The nuclear magnetic resonance spectra showed that the dominant P species in Bronx River bed sediments are orthophosphate monoester and lesser phosphate diesters and pyrophosphates (pyro-P). The P compounds were mostly glycerophosphate, nucleoside monophosphates, and polynucleotides. A few sites showed a small amount of dihydroxyacetone phosphate, inosine monophosphate. By allowing a downstream comparison of P compound variations along the Bronx River, this study provides a step toward improving water quality in an urban river system such as New York City and helps to assess the bioavailability of P, in turn, design estuary habitat restoration projects in comparable region of the world.

Use of a Parsimony Algorithm As a Method for Evaluating Ichthyofaunal Distribution and Co-occurrence in an Urban Stream

ABSTRACT The use of a parsimony algorithm as a method for graphically representing ichthyofaunal distribution and co-occurrence in an urban stream was evaluated using an extensive database of 23 fish species from the freshwater reaches of the Bronx River, New York, USA. The method, based on the idea of considering each sampling station as a “taxon” and the presence or absence of each fish species as a “character state” of that “taxon”, resulted in a single most parsimonious tree from which both species distributions throughout the river and the co-occurrence of the fish species at each of eight stations could be clearly visualized and evaluated. The nesting of the stations obtained by this procedure was compared with results from hierarchical clustering, detrended correspondence analysis, and nonmetric multidimensional scaling. This parsimony analysis technique provided information congruent with the above mentioned multivariate methods; in addition, it provided a unique graphical representation of community structure, a representation that is not readily available from traditional multivariate analysis program packages.