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Fernando Gómez-Gómez

Publications and source records attributed to Fernando Gómez-Gómez.

39 records · Page 3Linked to original sources
USGS1980

Reconnaissance of six solid-waste disposal sites in Puerto Rico and effects on water quality

Five solid-waste landfills and an open burning dump were studied in Puerto Rico to obtain physical, chemical and biological data on leachates, give an overview of their pollution potential, and determine the adequacy of monitoring at these or similar sites. These sites are operated by the municipal governments of Arecibo, Caguas, Cayey, Humacao, Mayaguez and Guayama. The bulk of waste is of domestic origin but wastes from local industries and institutions are also handled. Data were collected between February and July 1976. Parameters measured included temperature, specific conductance, pH, color, common ions, cyanide, macronutrients (nitrogen and phosphorus species), total organic carbon, dissolved oxygen, BOD5 (biochemical oxygen demand), COD (chemical oxygen demand), total and fecal conform, trace metals, and phenols. The results obtained indicated that leachate from most sites is enriched in common ions, macronutrients, and trace metals. A sample obtained from runoff at the Cayey landfill was the only one with an acidic pH (5.8). It had a common ion concentration of 10,750 mg/L (milligrams per liter), or twice that found in leachate contained within the buried refuse. The leachate from the Caguas site had the highest common ion concentration (12,520 mg/L). Maximum values for other parameters were as follows: Temperature, 33°C (or about 10°C above ambient ground-water temperature); specific conductance, 19,200 micromhos per centimeter; color, 2,200 units; cyanide, 30 ug/L (micrograms per liter); total nitrogen, 600 mg/L; total phosphorus, 4.3 mg/L; total organic carbon, 500 mg/L; 5-day biochemical oxygen demand, 5,540 mg/L; chemical oxygen demand, 3,000 mg/L; total coliform bacteria, 410,000 colonies per 100 milliliters; fecal coliform bacteria, 14,000 colonies per 100 milliliters; total arsenic, 54 ug/L; total cadmium, 15 ug/L; total chromium, 1,600 ug/L; total lead, 1,10C ug/L; total mercury, 2.6 ug/L; total nickel, 1,300 ug/L; and total phenols, 1,100 ug/L. Pollution of water resources is limited to the periphery of the sites. A major problem throughout seems to be related to operating methods. Under the conditions found, large quantities of rainwater and runoff could be available for leachate production. Generation of leachate may not be significant at present probably because of the recent establishment of the landfills (less than 5 years). Monitoring at these or similar sites in Puerto Rico can be limited to defining present baseline water-quality conditions and implementation of a sampling program. Baseline data could be limited to specific conductance, pH, color, common ions, and dissolved oxygen. A scheduled sampling program could be limited to specific conductance readings and measurement of concentration of bicarbonate, chloride, and dissolved oxygen.

Puerto Rico↗
USGS1980

Summary appraisals of the nation's ground-water resources – Caribbean region

The Caribbean Region consists of the Commonwealth of Puerto Rico (8,990 km 2 (square kilometers)) and the U.S. Virgin Islands (350 km 2 ). The mean annual precipitation varies locally from a high of 5,000 mm (millimeters) to a low of 730 mm. Maximum precipitation occurs within the peaks of Sierra de Luquillo, and minimum precipitation occurs along the windward parts of the smaller islands and in southwestern Puerto Rico, which lies in a rain shadow. The annual average precipitation is 1,800 mm in Puerto Rico and 1,061 mm in the U.S. Virgin Islands. Of this amount 1,130 mm in Puerto Rico and 990 mm in the U.S. Virgin Islands are lost to evapotranspiration. Aquifers constitute a valuable resource in the Caribbean Region. In Puerto Rico, ground-water withdrawals supply about 38 percent of the total water requirements, whereas in the U.S. Virgin Islands they supply 10 percent. Of the ground-water withdrawal of 350 hm 3 /yr (cubic hectometers per year) in Puerto Rico, 54 percent is used for irrigation, 29 percent is used by industry, and 17 percent is used for public water supply. Ground-water withdrawal in the U.S. Virgin Islands is about 1.9 hm 3 /yr and is almost equally distributed between public supply and privately owned wells. Based on past trends and future economic expectations in the region, estimates are that by 1985 ground-water pumpage in Puerto Rico will be about 426 hm 3 /yr with additional future development potential; U.S. Virgin Islands pumpage may amount to 4.5 hm 3 /yr, which is the estimated maximum sustained yield of all aquifers under natural recharge conditions. Most large ground-water developments in Puerto Rico have been in the North Coast and South Coast ground-water provinces. The North Coast province contains the island's most productive aquifer, which was virtually undeveloped until 1968, when an artesian system having a 150-meter head was tapped. Since then, the artesian aquifer has undergone rapid development for industrial water supply. The extent of the artesian system is unknown, but it has been tapped within the Montebello Limestone Member of the Cibao Formation and in the upper part of the Lares Limestone. The south-coast aquifer consists of deep alluvial deposits. This aquifer has been extensively developed for irrigation and industrial water supply and can sustain only minor future development under present water-management conditions. In the U.S. Virgin Islands the most extensive aquifer is fragmented igneous rock, but the most productive aquifers are the marl and alluvial deposits of central St. Croix. Although yields from wells in central St. Croix are low (less than 6.3 liters per second), the aquifer provides about 0.86 hm 3 /yr to public water-supply wells and 0.54 hm 3 /yr to private wells. Future development within this aquifer could probably produce an additional 1.0 hm 3 /yr under natural infiltration conditions. Ground-water resources will continue to be important within the region. In order to meet future needs, it is necessary that hydrologic principles be applied in managing the total water resource. Optimal use of the water resources can be accomplished through conjunctive use of surface and ground waters and through conservation practices. Optimal use may involve artificial recharge, ground-water salvage, saline-ground-water mining, use of seawater, desalination of saline ground water, waste-water reuse, and use of underground space for temporary storage of wastes, which could otherwise contaminate valuable water supplies.

Professional Paper↗