Urban runoff, metals

C from Furnas et al. (1976) for phytoplankton production and from the organic P reported by Nixon (1981) for rivers and sewage using a C P ratio of 106 1 by atoms. Total N and P inputs from Nixon (1981). Sewage includes urban runoff. Metals from rivers and sewage measured by Hunt (unpublished report). Cu in rivers also includes data for small rivers and smaller sewage treatment plants reported by Hoffman and Quinn (1989). Metals from atmosphere estimated from data for nearby areas summarized by Nixon and Lee (in press). Hydrocarbons from Hoffman and Quinn (1989), and E. Hoffman (pers. comm, as reported in Santschi et al. in press) include Mt Hope Bay inputs and area. 

Table 2 Fate and effects of metals in a stream receiving a point-source of metals (upper part of the table) or diffuse input via urban runoff (lower part of the table). Summary of the expected influence of four different hydrological situations base-flow in a rainy period a flood after a rainy period low-flow after a long period of low rainfall (water scarcity) and a flood produced after this drought. Metal concentration (M) metal retention efficiency (measured on the basis of the nutrient spiraling concept) exposure (dose and duration) bioaccumulation (in fluvial biofilms) and metal sensitivity (of biofihns)...

The second case (Table 2) illustrates a hypothetic urban stream receiving both metals and nutrients mainly via urban runoff. Since urban runoff is directly linked with rainfall episodes, metal inputs and exposure will be variable under base-flow during a rainy period and very low under a situation of water scarcity (low rain and low-flow). In this case, a sudden flow increase after strong rains may cause contrasting effects on water metal transport depending on the previous situation. If previous rains have already washed the metals retained in land and sediments, the... 

Campbell, K.R. 1994. Concentrations of heavy metals associated with urban runoff in fish living in stormwater treatment ponds. Arch. Environ. Contam. Toxicol. 27 352-356. 

Domestic and industrial wastewaters, sewage discharges, and urban runoff also contribute large quantities of metal pollution to the aquatic environment. These discharges often occur at point sources and can lead to excessive local Tietal burdens in water. 

Polynuclear aromatic hydrocarbons from urban runoff were found at elevated levels in nearshore sediment samples from Lake Pontchartrain. Concentrations decreased with distance from the New Orleans shoreline and approached background levels three to six miles offshore. Quantitative profiles for individual PAH isomers differed significantly between nearshore and offshore sediments. Similar trends were observed with chlorocarbons and lead, but concentrations of other heavy metals did not decrease with distance from the shoreline. Salt water Intrusion causes stratification over the southeastern portion of the Lake in the summer. This stratification contributes to and exacerbates bottom anoxic conditions during warm weather months. 

Contents indude fundamental concepts, urban runoff, sewage treatment, pathogens in natural waters, toxicology, industrial pollution, pesticides, metals, oil pollution, radioactivity, and ground water pollution. 

No data have been found on the amount of metal that leaches out of asphalt to enter the environment. Urban runoff, even from highly domestic areas, contains unexpected large quantities of metals. ... 

Total metal concentrations in the Mississippi River are elevated somewhat over average river waters (Table IV), except for polluted areas. The elevated concentrations of copper, cadmium, and lead at Site 4 compared to Site 3 are in part attributable to the discharge of treated sewage effluent and urban runoff. The Minnesota River may be important for all metals studied with the exception of cadmium. Under low flow conditions, 10 to 50% of the trace metal load to the Mississippi... 

Urban Runoff (petroleum products, metals, salts, silts, and sediments)... 

Brown JN, Peacke BM (2006) Sources of heavy metals and polycyclic aromatic hydrocarbons in urban stormwater runoff. Sci Tot Environ 59 145... 

Trace metals (arsenic, cadmium, chromium, copper, nickel, lead, mercury, zinc) Industrial and municipal wastewaters runoff from urban areas and landfill erosion of contaminated soils and sediments atmospheric deposition Toxic effects including birth defects, reproductive failure, cancer, and systemic poisoning. 

Storm water runoff from cities and villages presents another problem. This runoff contains salts from road deicing, street refuse, animal waste, food litter, residue from atmospheric deposition of sulfuric and nitric acid, metals, asbestos from automobile brakes, rubber from tires, hydrocarbons from motor vehicle exhaust condensates, oil and grease, soil and inorganic nutrients from construction sites, and a variety of other chemicals. Research shows a heavy impact of urban nonpoint pollution on freshwater quality (World Resources Institute, 1988). 

Characklis, G.W., Wiesner, M.R. (1997) Particles, metals, and water quality in runoff from large urban watershed. Journal of Environmental Engineering -ASCE, 123(8) 753-759. 

The extensive use of lead antiknock additives in gasoline has made lead perhaps the most widely distributed toxic heavy metal in the urban environment and has greatly increased its availability for solution in natural waters. It is important for this reason to know whether its introduction into surface and ground waters by rainfall and runoff will make it available for solution or whether chemical processes will place a safe upper limit on its solubility. 

Experimental. The sediment used in this study was obtained from Colma Creek, at Serramonte Boulevard between El Camino Real and Junipero Serra Boulevard, in the city of Colma, San Mateo County, California. Colma Creek was chosen because its entire course occurs within an area of urbanization, and the sediments are therefore of the type which normally come in contact with lead and other heavy metals. The main sources of lead, atmospheric fallout and rainfall runoff contain particulate matter from automobile exhaust emissions. Several shovels full of the bottom material were placed in a plastic container. In the laboratory, several kilograms of the material were wet-sieved, and the fraction passing through a 200-mesh sieve (particle diameter less than 74 ym) was placed in a 1-liter graduated cylinder containing a 1 M sodium phosphate solution. The silt fraction settles in this medium while the finer clay particles remain suspended. After several hours, this clay suspension was then decanted and a portion of the material saved for X-ray diffraction, as were portions of the sand and silt fractions. 

The metals have the tendency to form compounds of low solubility with the major divalent cations (Pb, Cd being found in natural water. Hydroxide, carbonate, sulfide, and, more rarely, sulfate may act as solubility controls in precipitating metal ions from water. A significant fraction of lead and, to a greater extent, cadmium carried by river water is expected to be in an undissolved form. This can consist of colloidal particles or larger undissolved particles of lead carbonate, lead oxide, lead hydroxide, or other lead compounds incorporated in other components of surface particulate matter from runoff. The ratio of lead in suspended solids to lead in dissolved form has been found to vary from 4 1 in rural streams to 27 1 in urban streams. The US Environmental Protection Agency (USEPA) has reported Maximum Contaminant Levels in water that are permissible to be 0.005 m L for cadmium and 0.015 mg/L of lead. ... 

Concrete, metal or plastic pipes are conventionally used in stormwater sewers for urban surface runoff drainage. A stormwater sewer pipeline is laid parallel to the ground surface with a cover of more than 0.9 m. Scrap tire pipes may be used as the construction material of storm drainage systems in small towns if the pipes can provide required flow capacity. 

Sewage treatment plants are very efficient at removing lead and other heavy metals from raw sewage. They thus act as effective controls on lead discharges not only within domestic sewage but also from industrial sources and urban stormwater runoff, both of which are frequently directed to sewage treatment plants. 

Shinya, M., Tsuchinaga, T., Kitano, M., Yamada, Y., Ishikawa, M., 2000. Characterization of heavy metals and polycychc aromatic hydrocarbons in urban highway runoff. Water Sci. Technol. 42, 201-208. 

Turer, D., Maynard, J.B., Sansalone, J.J., 2001. Heavy metal contamination in soils of urban highways comparison between runoff and soil concentrations at Cincinnati, Ohio. Water Air Soil Pollut. 132, 293-314. 

The increased frequency of storms due to global warming has resulted in the contamination of surface water and groundwater from industrial effluents, municipal sewage, urban storm water runoff, and agricultural runoff [48, 49]. As a result, water sources used for human consumption have become more contaminated with heavy metals, POPs, pesticides, fertilizers, chlorination by-products, and pharmaceuticals [48]. 

For estuarine and coastal environments, direct deposition to the water s surface of some pollutants can be as important as runoff from the watershed given that the metals are strongly retained within the terrestrial environment (22, 24). Atmospheric deposition appears to be an important source to the Chesapeake Bay of metals such as Hg, Pb and Cd (3, 5, 20). However, as estimations are based on the measurements of metal deposition at rural sites, they could potentially underestimate the impact of deposition if the urban influence were significant. The present study was aimed at examining the difference in concentration and deposition in an urban and a rural setting to help address this important question. 

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