Heavy rains

A more constrained opportunity for nitrate bioremediation arose at the US-DoE Weldon Spring Site near St. Louis, Missouri. This site had been a uranium and thorium processing faciUty, and treatment of the metal had involved nitric acid. The wastestream, known as raffinate, was discharged to surface inpoundments and neutralized with lime to precipitate the metals. Two pits had nitrate levels that requited treatment before discharge, but heavy rains in 1993 threatened to cause the pits to overflow. Bioremediation by the addition of calcium acetate as a carbon source successfully treated more than 19 million liters of water at a reasonable cost (75). 

Wintertime operation.s. In addition to the previously discussed problems of winterization, provision must be made for heavy rain, strong winds, freezing of moisture upon the fins, etc. 

If heavy rain causes a flash flood at the site of installation, the motor may be submerged in water for some time. A reasonably good motor, with good... 

Ground radiation is from deposited radioactive particles. The deposition rate from a radioactive cloud without rain (dry deposition) is so low that the ground radiation dose is about the same as the inhalation dose. A heavy rain, however, may wash out enough particles from the plume to make ground radiation the dominant contributor to the total dose in a limited area. Rain will also attenuate radiation by leaching the radioactivity to be shielded by the soil and by moving it to streams for further removal. 

Heat loss varies greatly with weather conditions and is usually the greatest in heavy rain and extreme cold. As an approximation it can be assumed that the heat lost from the heater to the atmosphere is less than 10% of the process heat duty. Therefore ... 

A welder w as constructing a new pipeline in a pipe trench, while 20 m away a slip-plate was being removed from another pipe, which had contained light oil. Although the pipe had been blown with nitrogen, it was realized that a small amount of the oil would probably spill when the joint was broken. But it w as believed that the vapor would not spread to the welders. Unfortunately, the pipe trench was flooded after heavy rain, and the oil spread across the water surface and was ignited by the welder s torch. One of the men working on the slip-plate 20 m away was badly burned and later died. 

In other cases, spillages of oil have soaked into the ground and have then come to the surface after heavy rain. A spillage of gasoline in Essex. England, in 1966, came back to the surface two years later. The vapor accumulated on the ground floor of a house, ignited, and blew a hole in... 

An old pipeline, no longer used, was marked with chalk at the point at which it was to be cut. Before the mechanic could start work, heavy rain washed off the chalk mark. The mechanic "remembered" where the chalk mark had been and he was found cutting his way with a hacksaw through a line containing a hazardous chemical. 

First evidences of the impact of heavy rainfall on the epidemiology of enteric pathogens were obtained from studies on the presence of various faecal organisms, both pathogens and indicators in water. Increased numbers of pathogens and indicators in different water bodies, including drinking water, had been reported after heavy rains. 

In contrast, in developing countries published information on this topic is scarce, though existing information indicates that rain levels above background values also increase the amoimts of indicators in fresh water bodies. Blum et al. [32] described in Nigeria a peak period of faecal pollution of water sources in the transition between the dry and the wet seasons. Gasana et al. [33] described boosts of faecal contaminants in water supplies in Rwanda after heavy rain episodes. 

Very little evidence associating water scarcity and an increase in outbreaks of faecal-oral water-borne infectious diseases exists in developed countries. A recent retrospective study performed in England provides some evidence that both low rainfall and heavy rain precede many drinking water outbreaks [3]. Yet, as stated earlier in this review, the situation is potentially different in developing countries [5-7, 9-12], where water scarcity, including droughts, leads to different circumstances that have a clear incidence in the occurrence of both water-borne and water-washed infectious diseases. 

On the contrary, there are numerous reports of outbreaks of faecal-oral waterborne infectious diseases following heavy rain episodes. 

In developed countries heavy rain events not followed by floods have frequently been associated with outbreaks linked to drinking water supplies derived from... 

The exploratory study Is not designed to obtain Information on temporal patterns In the chemical concentrations since these studies are expected to be completed In a short period of time. If It Is possible to select the time for the exploratory study. It should be conducted at a time when the concentrations would be expected to be at a maximum. It may be necessary to use the hypothesized dispersion model In order to make this decision. For example, the sampling normally should not be done Immediately following a heavy rain, when the ground Is frozen solid, or when a wind Is blowing at 20 to 30 knots. Temporal trends will have to be addressed In the final study. 

A large dump of copper pyrites ore ignited after heavy rain. The thick layer (6-7 m) and absence of ventilation were contributory factors to the accelerating aerobic oxidation which finally led to ignition. 

The cutting of terraces on rubber plantations situated on hilly areas, with the object of preventing the loss of top soil during heavy rain. Terylene... 

On July 10,1976, the trichlorophenol reactor went out of control, resulting in a higher than normal operating temperature and increased production of TCDD. An estimated 2 kg of TCDD was released through a relief system in a white cloud over Seveso. A subsequent heavy rain washed the TCDD into the soil. Approximately 10 square miles were contaminated. 

In the Asian region with prevalent monsoon climate and heavy rain events during rain seasons, surface runoff plays the most important role in the environmental pathways of many pesticides. The major factors influencing the amount of pesticides carried away by runoff are as follows (Richter, 1999) ... 

After weeks of heavy rains, the earth gave way mud and trees down the mountain swallowing cars and houses in their path. 

Precipitation heavy rain dilutes and disperses chemical weapons snow increases persistence. 

The problems of diseases and pests will not be solved merely by a chemical formula that inhibits or destroys fungus spores in vitro. A pesticide ought to have the ability to remain on the plant surfaces long enough to prevent or destroy disease agents and to destroy disease vectors before they attack. This is difficult to achieve under the severe weather conditions of the tropical moist forest, the natural habitat of cacao, where the chemical deposited is in many cases washed away by heavy rain. The inherent tenacity of a fungicide could be improved by the addition of adhesives. An effective adhesive or an alternative for use in combination with fungicides or insecticides in the tropics has not yet been developed. 

Most fungicides, especially the organic ones, have residual capacity markedly inferior to that of Bordeaux mixture. However, the tenacity could be improved by the addition of adhesives, especially when used in regions of heavy rain. Only preliminary trials in Costa Rica have been conducted in this important problem. Of 14 stickers tested on cacao seedlings in relation to the control of Phytophthora rot of cacao, none gave satisfactory results. 

Keep it covered Persistent heavy rain can erode soil and leach out its nutrients. A covering of plants, or in winter, a mulch over bare ground, protects the soil structure. 

To protect soil Green manures protect soil from compaction by heavy rain, particularly relevant to heavy clay. Green manures also mop up plant foods from the soil, so they are not washed out by rain, but are returned to the soil when the plants remains decay. 

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