WSP00818 - Laserfiche WebLink

Home Browse Search

continual increase in hardness would, in most cases, accelerate these physical effects. C. Industrial N; 0') CJt I;\.) The effect of water quality on industrial uses is difficult to generalize because of the varied uses required by industry. One method is to classify industrial water use by purpose, such as cooling, boiler feed, process, or general purpose. When raw water does not meet quality criteria for the specific purpose or purposes, treatment methods are required which include water softening, evaporation, demineralization, chromatic addition, and chlorination in cooling systems for control of corrosion and slime. For example, cooling water may be used for a variety of purposes, including the cooling of condensers, internal combustion engines, and compressors. Among the constituents of natural water that may prove detrimental to its use for cooling purposes are hardness and suspended solids. On the other hand, the quality of boiler feed water is a significant factor in the (1) rate of scale formation on heating surfaces, (2) degree of corrosion to the system, and (3) quality of produced steam. Process water is used in preparation of the products of industry. This water is either incorporated directly into the finished product or used in transporting, mixing, washing, dissolving, concentrating, or cooking operations. Industry also uses general-purpose water for plant personnel needs, general cleaning, lawn watering, and fire protection. D. User Alternatives , The physical impacts of salinity upon consumptive uses of water are translated into economic values by evaluating how each user might alleviate the effects of salinity increases. When confrontation of the problem is ultimately required of the user, alternatives are rapidly discovered and/or available which mitigate the physical and economic effects of higher salinity levels. The alternatives considered in the study are outlined below. 1. Agriculture. The alternatives available to irrigation water users are influenced by the availability of additional water. The primary means of combating detrimental salinity are to switch to substitute crops less affected by salinity. or to apply more irrigation water to keep the excess salts moving out of the root zone and maintain soil permeability. a. If the irrigator does nothing. economic loss from decreased crop yields can be expected. b. If additional water is available, root zone salinity may be reduced by increasing leaching water applications. The irrigator would incur increased costs for purchase of water. for additional labor for water application, and for increased application of fertilizer to replace the fertilizer leached out. c. If no additional water is available. the irrigator can increase the leaching of salts from the soil by applying the same amount of water to lesser acreage. This, of course. results in an economic loss since fewer acres of crops can be grown. d. By changing the management regime and applying alternative production practices, some salinity effects can be mitigated. but only by incurring additional costs. These alternatives include drain installation. ditch lining, land leveling. deep plowing, planting bed modification. sprinkler and drip irrigation, and increased irrigation frequency. e. The last altenative is to plant salt-tolerant crops. An economic loss would usually occur since many salt-tolerant crops ordinarily produce a lower economic return. 2. Municipal. Municipalities could: (a) do nothing and the residents would consume more soap and detergents or purchase home softening units. Households would experience accelerated frequency of replacement of water-related facilities. (b) build central water softening plants. and (c) develop new. less mineralized water supplies. 3.' Industrial. Industrial users could combine more extensive treatment of their water supply with the purchase of additional makeup water based upon the economics of prevailing conditions. The required mineral 4