Runoff annual

Enter the applicable letter code for the receiving stream or water body from Section 3.10 of Part I of the form. Also, enter the total annual amount of the chemical released from all discharge points at the facility to each receiving stream or water body. Include process outfalls such as pipes and open trenches, releases from on-site wastewater treatment systems, and the contribution from stormwater runoff, if applicable (see instructions for column C below). Do not include discharges to a POTW or other off-site wastewater treatment facilities in this section. These off-sife transfers must be reported in Pari III, Section 6 of the form. 

If your facility does not have periodic measurements of stormwater releases of the chemical, but has submitted chemical-specific monitoring data in permit applications, then these data must be used to calculate the percent contribution from stormwater. Rates of flow can be estimated by multiplying the annual amount of rainfall by the land area of the facility and then multiplying that figure by the runoff coefficient. The runoff coefficient represents the fraction of rainfall that does not infiltrate into the ground but runs off as stormwater. The runoff coefficient is directly related to how the land in the drainage area is used. (See table below.)... 

Ordinate shows percentage of annual runoff that normally occurs in each month of the year... 

Fig. 6-9 Annual runoff patterns for the United States. Percent of normalized annual runoff in each month. (From Langbein and Wells, 1955.)...

May-June runoff peaks, 2 to 2.5 times the aimual average nmoff in the 1915-1924 period prior to dam construction, were barely 1.5 times the average flow between 1985 and 1994. Meanwhile, autumn low flows during the 1985-1994 period are close to the mean annual flow, compared to low flows at about half the mean prior to river regulation. 

Fig. 9-8 Histogram of dissolved solids of samples from the Orinoco and Amazon River basins and corresponding denudation rates for morpho-tectonic regions in the humid tropics of South America (Stal-lard, 1985). The approximate denudation scale is calculated as the product of dissolved solids concentrations, mean armual runoff (1 m/yr), and a correction factor to account for large ratios of suspended load in rivers that drain mountain belts and for the greater than average annual precipitation in the lowlands close to the equator. The correction factor was treated as a linear function of dissolved solids and ranged from 2 for the most dilute rivers (dissolved solids less than lOmg/L) to 4 for the most concentrated rivers (dissolved solids more than 1000 mg/L). Bedrock density is assumed to be 2.65 g/cm. (Reproduced with permission from R. F. Stallard (1988). Weathering and erosion in the humid tropics. In A. Lerman and M. Meybeck, Physical and Chemical Weathering in Geochemical Cycles," pp. 225-246, Kluwer Academic Publishers, Dordrecht, The Netherlands.)...

Fig. 2 Relative changes (between 2080-2099 and present, 1980-1999) of annual surface runoff on the globe, from results of several climate models forced by emissions of scenario AIB. Dashed areas indicate that more than 90% of models agree with the sign of change. Taken from IPCC [1]...

Though extremes are part of the normal hydrologic behaviour in Mediterranean-type rivers, a consistent trend of water flow decrease has been described in many of these systems. The Ebro is the largest Iberian river flowing into the Mediterranean Sea. The flow records at its mouth (mean annual runoff 13,408 Mm ) show a decrease of nearly 40% in mean annual flow in the last 50 years. The forces behind these flow decreases are multiple. Higher water withdrawal, climate change and... 

The water supply to the Delta comes predominantly from the Sacramento River ( 80%) with lesser amounts from the San Joaquin River ( 15%) and rivers on the east side of the Delta ( 5%). Year-to-year variability in water supply is large. Combined average annual unimpaired runoff (an estimate of flows without upstream dams or diversions) for the Sacramento and San Joaquin rivers for the past century ranges from 6.2 km in 1977 to 68 km in 1983 [2]. The percentage of freshwater flows that go to San Francisco Bay are estimated to be 87% in wet years, 69% in average years, and 51% in dry years. Climate variability associated with the Mediterranean chmate of the region is an essential component of the Delta ecosystem. 

Average monthly and annual values for pesticide runoff... 

The regulation of the Ebro River in the 1960s completed an irreversible change of the discharge pattern. The dams substantially altered flood timing, particularly of the flood peaks [26, 27]. Batalla et al. [28] analyzed flow records from 22 rivers to determine the effects of reservoirs on flow regime (flood frequency, flow duration of mean daily flows, monthly regime, and annual runoff) before and after dam construction. This research shows that variability of the mean daily flows was... 

The main economic use of the Ebro River has been hydropower and irrigation. The Ebro River has 187 reservoirs impounding 57% of the mean annual runoff. Such a large number of reservoirs deeply alter the fluvial regimes. None of the major dams in the basin was built for flood control, but the sheer volume of the impoundments affects the flood magnitude. Diverted water is used mainly for hydropower production and for irrigation. All the dams were constructed during the twentieth century,... 

Fig. 3 Long-term annual runoff in key hydrological locations along the basin (a) Ebro in Tortosa, (b) Segre in Seros, (c) Ebro in Zaragoza and (d) Cinca in Fraga. See Fig. 1 for geographical references...

There are 318 river gauging stations within the Ebro basin [80]. Around 60 of these monitor natural flow regimes and are typically located around the edges of the basin in the medium to higher reaches of the tributary rivers [8], Others are located on rivers whose streamflow has been altered by reservoirs (see [9] for a review of historical water policy in Spain). In total, 187 reservoirs impound 57% of the mean annual runoff [10]. As an example, annual discharge measured... 

In the United States, about 80% of the 23 million kg of technical PCP produced annually — or about 46% of worldwide production — is used mainly for wood preservation, especially utility poles (Pignatello etal. 1983 Kinzell etal. 1985 Zischke etal. 1985 Choudhury etal. 1986 Mikesell and Boyd 1986 USPHS 1994). It is the third most heavily used pesticide, preceded only by the herbicides atrazine and alachlor (Kinzell et al. 1981). Pentachlorophenol is a restricted-use pesticide and is no longer available for home use (USPHS 1994). Before it became a restricted-use pesticide, annual environmental releases of PCP from production and use were 0.6 million kg to the atmosphere from wood preservation plants and cooling towers, 0.9 million kg to land from wood preservation use, and 17,000 kg to aquatic ecosystems in runoff waters of wood treatment plants (USPHS 1994). There are about 470 wood preservative facilities in the United States, scattered among 45 states. They are concentrated in the South, Southeast, and Northwest — presumably due to the availability of preferred timber species in those regions (Cirelli 1978). Livestock facilities are often constructed of wood treated with technical PCP about 50% of all dairy farms in Michigan used PCP-treated wood in the construction of various components of livestock facilities (Kinzell et al. 1985). The chemical is usually applied to wood products after dilution to 5% with solvents such as mineral spirits, No. 2 fuel oil, or kerosene. More than 98% of all wood processed is treated with preservative under pressure about 0.23 kg of PCP is needed to preserve 1 cubic foot of wood (Cirelli 1978). Lumber treated with PCP retains its natural appearance, has little or no odor, and can be painted as readily as natural wood (Wood et al. 1983). 

However, only the smallest part of soluble metals is involved in the biological cycle. Most of these are either lost to water runoff, or retained in the peat organic matter. The latter is the source of gradual remobilization but the whole mineralization may last up to 50 years or even more. The total accumulated retained amount of macro-or trace metals in organic matter of peat is tens and hundreds of time higher than the concentration of annually released soluble forms, which are available for plants. 

The Mangrove ecosystems perform a role of biogeochemical barrier, which decreases significantly the runoff of chemical species from the coast to the ocean waters. This is correlated with the major biogeochemical parameters of these ecosystems such as high productivity and high values of annual biogeochemical fluxes and relevant exposure rates. 

Marsalek J, Schroeter H. 1988. Annual loadings of toxic contaminants in urban runoff from the Canadian Great Lakes basin. Water Pollution Research Journal of Canada 23(3) 360-378. 

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