Ground and surface waters

The harmful effects of intensive agriculture on ground and surface water are caused mainly by the following practices (Stolze et al. 2000, Alfbldi et al. 2002)  

In areas where water is scarce (e.g. in the Mediterranean countries and in arid and semiarid 

The general conclusion that can be drawn from the literature is that organic farms often have smaller nutrient surpluses than conventional farms. Obviously, the same farm types need to be compared because livestock farms often have higher nutrient surpluses. It follows that in organic farming, the risk of water and air contamination as a consequence of nutrient surpluses tends to be lower (Stolze et al. 2000, Shepherd et al. 2003). 

Restrictions in organic standards include a ban of mineral N fertilisers and a limitation of livestock density. More characteristic of organic farms, therefore, is that N tends to be a minimal factor, particularly on arable farms. Since the opportunity costs to produce N on-farm in organic systems can amount to from seven to 16 times the cost of mineral N fertilisers (e.g. Stolze 1998), it is of particular economic interest to avoid N losses. As far as nutrient deficiencies are concerned, Unwin et al. (1995) argue that the medium-term effects of an unbalanced nutrient supply are likely to take the form of a reduction in economic performance rather than environmental detriment. 

Taking all these factors into account, overall leaching losses from organic farms tend to be 

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Possible negative environmental effects of fertilizer use are the subject of iatensive evaluation and much discussion. The foUowiag negative effects of fertilizer usage have been variously suggested (113) a deterioration of food quaUty the destmction of natural soil fertility the promotion of gastroiatestiaal cancer the pollution of ground and surface water and contributions toward the destmction of the ozone layer ia the stratosphere. 

Balinova AM, Mondesky M. 1999. Pesticide contamination ground and surface water in Bulgarian Danube Plain. J Environ Sci Health B 34(l) 33-46. 

For the sake of completeness, attention is drawn to physical procedures for removal of contaminants and for their chemical destruction. A valuable review by Hamby (1996) summarizes chemical and physical treatments of soils and contaminated ground and surface waters. Examples include the following ... 

Acetochlor, alachlor, and metolachlor are determined in ground and surface water samples. Deuterated internal standards are added to each water sample, and analytes are extracted using an SPE column. After elution and concentration to an appropriate volume, the analytes are quantitated by GC/MS. 

The following is a general method for ground and surface water samples. Interferences in particular samples may require modification of this method. The analytical sample size is 200 mL, but the volume may be varied depending on the concentration of analytes in the sample. 

Low-level interferences are present in ground- and surface water samples. The water-methanol (4 1, v/v) wash in the SPE phase of the sample workup is intended to minimize these interferences while maintaining quantitative recovery of the analytes. A solvent blank may be injected with the samples as part of an analytical set to confirm the cleanliness of a solvent used. 

At least one control water sample must be analyzed concurrently with the water samples to determine the presence of matrix interferences and/or background levels of the metabolites. Optima-grade bottled water is used as the matrix for the controls and the fortified samples for all wafer fypes, because obtaining ground and surface water specimens that are completely free of the metabolites is difficult. Our analyses of ground and surface waters have demonstrated the presence of low-level interferences in these matrices. Interferences from other pesticides are unknown, because none have been examined. However, none are expected due to the high level of specificity of the LC/MS/MS analysis. 

Environmental pollution caused by pesticides has become a serious problem. Especially during and/or after pesticide application to crops, the pesticides are released into sensitive environmental areas, and also into ground and surface water, and could be harmful or dangerous to humans and other species. Therefore, very low concentrations of diphenyl ether herbicides in environmental waters must be monitored. 

Recovery data from ground and surface water are summarized in Tables 1 and 2. 

However, the contributions of sulfate, acid and metals from ground and surface waters that interact with the numerous tailings and waste rock dumps located... 

This paper outlines a novel approach to maximising the value of kinetic data by combining mineralogy, aqueous geochemistry and kinetic test data to design ground and surface water exploration programs. The approach is tested on environmental data collected by Adanac Molybdenum Corporation at the Ruby Creek Molybdenum project, Atlin, BC, Canada. 

Detailed interpretation of kinetic test data collected for environmental purposes has allowed criteria for ground and surface water geochemical exploration to be selected. Parameters predicted from kinetic testing to be anomalous in both ground and surface waters were observed to occur reflecting the presence of both molybdenum mineralization and natural acid rock drainage. Kinetic testing is very expensive and careful use of the acquired... 

Table 2. Significant differences between median (mg/L) background (BACK) and mineralized(MINER) area in ground and surface water in the Ruby Creek Watershed...

The potential for leaching or adsorption by plants has been thoroughly studied for LAS but not so much for the other surfactants (see Chapter 6.5). Thus, it is still a topic of recent studies, since this path represents a potential source for surfactants and their metabolites, which have not been entirely destroyed during sludge processing, to find a way into the terrestrial environment and from there into ground and surface water by leaching or run-off [53,54]. 

Another type of reaction that responds to WD cycles is the fixation of K and NH4 ions by smectite (3-7). The fixation of K in smectite has been studied extensively by soil scientists because of its effect on the availability of plant nutrients. The reaction also decreases smectite s ability to swell, decreases its cation exchange capacity (CEC), and modifies its BrjSnsted acidity. Therefore, an understanding of this phenomenon is applicable to many fields of study that are concerned with swelling clays, fields such as soil fertility, soil mechanics, waste disposal, clay catalysis, and the geochemistry of ground and surface waters. 

Cadmium is found naturally deep in the subsurface in zinc, lead, and copper ores, in coal, shales, and other fossil fuels it also is released during volcanic activity. These deposits can serve as sources to ground and surface waters, especially when in contact with soft, acidic waters. Chloride, nitrate, and sulfate salts of cadmium are soluble, and sorption to soils is pH-dependent (increasing with alkalinity). Cadmium found in association with carbonate minerals, precipitated as stable solid compounds, or coprecipitated with hydrous iron oxides is less likely to be mobilized by resuspension of sediments or biological activity. Cadmium absorbed to mineral surfaces (e.g., clay) or organic materials is more easily bioaccumulated or released in a dissolved state when sediments are disturbed, such as during flooding. 

The protection of ground and surface water has major environmental priority because any contamination may cause a risk for its use in human and animal nutrition and may disturb aquatic biocoenosis. The OECD-indicator list (OECD 1997) subsummarises state and risk assessment approaches under this issue. We will confine our efforts to indicators that are appropriate to evaluate the impact of different farm management practices. 

Organic farming poses no risk of ground and surface water pollution by synthetic pesticides. The active ingredients of permitted pesticides have not been properly monitored nor their effects sufficiently investigated. 

A conclusive assessment of the effects of organic farming on ground and surface water is given in the following table (Table 4-10) ... 

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