BLOG LATEST POSTSDo Not Water Your LawnDecember 18, 2017Blog Do Not Water Your Lawn By: Paul Collar Paul is a civil engineer and geologist and the publisher of this newspaper. You may reach him at solutions@osawaterworks.com Costa Rica gets an average of 2.5 meters of rainfall per year. Parts of the Osa get over 5 m per year. The Southern Zone of Costa Rica gets up to three annual rice harvests a year from native rainfall alone. It might be surprising to learn, therefore, that there are no small number in Costa Rica that consider irrigation of lawns during the dry summer months some sort of inalienable right, perhaps even factored right into the rentista or inversionista clauses of residency law. The preening lawn is of course one of America’s curious cultural heritages. The smell that fresh mown grass evokes in even me is like apple pie or that of a new car. Yet I am fooled by my nostalgic whimsy. Many of my fellow ex-pats that build in residential developments or private fincas here must be as well, for they often bring irrigation with them to perk up their beautiful lawns during the summer months when they mostly visit. In developed-world societies, water is often perceived as bountiful—no more than a hose bib away—and little thought is given to watering the lawn. If it is July in Arkansas, it is time to turn on the sprinklers, end of story. Yet this activity is fraught with environmental recklessness, not just in paradises like Costa Rica, but everywhere, even in Arkansas. There are many instances in which irrigation serves a purpose in which a cost/benefits analysis can be used to debate its merits, particularly amid the geopolitical minefields of climate change. But watering lawns in Costa Rica is different. In societies in which supply and demand is factored into utilities costs, a person that can afford to pay for the water required should have every right to water his or her lawn. Nevertheless, this activity has only a single tiny upside, the subjective aesthetic of a single person, the owner of the lawn, and a galaxy of downsides, irrespective of whether or not you can afford it. Let’s look at a few of those downsides. First of all, lawn irrigation requires more water than human consumption and use. For instance, irrigation recommendations for golf courses in Costa Rica call for 5 mm of water per day. Across a single hectare this adds up to 9.2 gallons per minute of continuous water every day. Costa Rican potable water design criteria call for 375 liters per person per day, equal to 0.07 gallons per minute. In other words, the water required to irrigate one hectare of lawn to golf course standards is equal to the residential water demand of 131 people. A day’s worth of water for a human being is equal in water equivalence, therefore, to 76 square meters of lawn, about 0.02% of the average green, for instance, at Los Sueños’s La Iguana 18-hole course. The water criteria backed out for the entire facility acreage is about equal, therefore, to the daily potable water needs of 75,000 people. Secondly, irrigation consists of the diversion of liquid water from whatever its source—well, stream, river, spring, municipal—to atmospheric water vapor, since up to 70% of irrigation water in the tropics is lost to the atmosphere as evapotranspiration. A fraction is incorporated in the biomass of grass, the rest percolated in soils or lost as runoff to streams. During the dry summer months, the transfer of valuable surface water to the atmosphere is the opposite of what the thirsty forest and rural populations and small towns need. Since the false-equivalent upside is a single individual’s aesthetic contentment over the look of his or her lawn, yard irrigation arguably blossoms into an argument centered not merely in environmental protection, but indeed in social justice. Thirdly, rural sources of water include not just deep wells but also springs, streams and rivers. These water sources are typically prolific in the rainy season, when irrigation is “unnecessary.” But surface flow dims with the deepening of summer. Though ground water levels have been lowered from over-development in arid and tourism-popular parts of the country, ground water remains a prolific source of water. If you must water your lawn, then you should use this option and solace yourself with your sacrifice in high power costs to pump this water and introduce it to the atmosphere by way of your lawn. But to take this vital commodity of water away from a surface stream or spring and from nature and our forest’s animals that depend on it to give it to the sky, all for the vanity of a single homeowner’s affection for his lawn, is moral turpitude: a misdemeanor perhaps for those that have not yet thought it through, a high crime for those that do so despite knowing better. Finally, lawn watering is a purely foreign import. Ticos don’t have the same suburban affection for a lawn that many ex-pats, Americans in particular, do. In fact, water law proscribes the use of public water from A y A and local asadas for irrigation use. Metropolitan suburbs of San Jose are reduced yearly to rationing water in April, when water shortfalls pop up all over the nation. Watering lawns in Escaleras as people carry water in five-gallon buckets in Desamparados is a jarring image that ex-pat homeowners will want to consider during landscape design of a dream home in paradise. Forests and established tropical ecosystems get by in even the driest years without much dying. But saplings and plantings from reforestation efforts require irrigation. Sustaining and nurturing seedlings and young plants with water, particularly young fruit trees and hardwood reforestation saplings, is essential and an appropriate and key use of irrigation. Low-tech, inexpensive drip irrigation concentrates the water where it is most needed for conscientious and ethical irrigation practices and is the least wasteful and most effective form of irrigation. California has long enjoyed a reputation as the vegetable and fruit bin of America. Yet the agricultural ascendancy of the Imperial Valley was founded on the unsustainable exploitation of a resource that was not renewable at the prevailing rates of extraction. Today’s Midwest of the United States, America’s bread-basket, is founded on “limitless” water from the Ogallala Aquifer that stretches across the midcontinent and contains 10,000 year-old glacial melt water that has little recharge today and supplies 30% of all the irrigation water used in the United States. It’s a non-renewable resource. In fact it’s a mine: a water mine that will be depleted as early as 2028. America’s wheat and almonds, therefore, have been agricultural industries not too unlike the mining of a finite mineral resource, in this case water. Once that water is gone, those almonds and bushels of wheat can no longer be produced, end of story. This is not hypothetical but a simple fact, and we are sliding down the falling tail of agro-industry curves. The boundless frontier turns out in the midterm to not be so boundless after all. In Costa Rica, ground water levels have fallen from over-pumping as well, mostly in Guanacaste and largely the result, government and media sources remind us, of poorly controlled over-exploitation of tourism resources in the arid northwest. But despite that, Costa Rica is a bit of a different story from California and the American Midwest. Costa Rica is still the motherlode of water, practically all of it renewable. In fact, the water that falls as rain on Costa Rica is enough to supply 49 liters every day to every man, woman, and child on the planet. As one of the most verdant spectacles on earth, the Republic of Costa Rica is optimal for appropriate landscaping for upscale homes and should not have to depend on irrigation at all. Consider drip irrigation for vegetable and herb gardens, young trees, and other sensitive plants, hand-watering of house plants, but if you opt for a Saint Agustin lawn you should let it get brown in the summer and keep our scant dry season hydric resource in the forest where it is needed most. Think feng shui. Look to local ornamentals, manicillo ground cover, veriver for slope stabilization, and like plants already steeped in equilibrium with our natural environment. Lawn watering is a zero-sum frittering of a vital resource. Husbandry of this resource through responsible drip irrigation can be a win-win alternative, so long as it does not remove environmentally key water from sensitive watersheds. If you must water at all, please don’t spray. Drip instead See the original article here... Gabion Retaining Wall: Do It Yourself!December 18, 2017BlogGabion Retaining Wall: Do It Yourself! By: Paul Collar Paul is a civil engineer and geologist and the publisher of this newspaper. You may reach him at solutions@osawaterworks.com With the many steep slopes of the Osa, the often saturated soils, and the high clay content and frequency of earthquakes, retaining walls are common backyard civil engineering features. Whether at the residential scale to shore up a steep bank or to terrace a slope for gardens or to contain the cutting edge of a creek or river, or at the civil works scale of building roads and bridges, dams, and other structures, the gabion is often the basic building block used for retaining walls. The first recorded use of the gabion was by Leonardo da Vinci, and the word itself is derived from the Italian gabbia, or cage. The gabion cage—or basket—was patented in Italy in the late 1800’s. In contemporary times, the gabion wall is often preferred to poured and anchored concrete structures due to lower cost. But for the do-it-yourself Osa finca owner, gabions are a great option not just for low cost but because they don’t require permits, special tools or know-how, and are easy to engineer. Here’s what you need to know to get started. Gabions work because of their weight. They are in effect, piles of rock, albeit neatly ordered inside galvanized iron baskets. Gabion walls do not require anchoring structures and like gravity dams achieve their function on the basis of weight alone. They last as long as the wire baskets hold up to corrosion and have a life expectancy of 50 years, surely less on the Osa. The sheer mass of the wall of rock creates resistance to being moved, hence to overturning. The design principle is that the overturning resistance force exceed the forces of soil creep and failure pushing against the wall. A rule of thumb is the steeper and higher the slope, the greater mass required. But for walls of less than 30 feet or so on non-vertical slopes, a single row of gabions is more than enough. Those seeking to go through the entire design process can find this elsewhere. For the DIY gabion enthusiast, there is an engineering credo not unlike the medical profession’s “First, do no harm.” It goes, “when in doubt, build it stout.” For best results, walls should be battered, that is, angled into the slope being retained. A slope of 6 degrees is typically adequate. Gabion baskets, or mallas, have dimensions of 1m x 1m x 2m and are the building blocks of the gabion wall. For each gabion, two cubic meters of cobble rock are required. A full dump truck provides the rock, therefore, for six gabions. The first step is to lay out the design, taking into account the point where the wall must end on the upper slope and the height of the wall to its logical base. You will likely need to excavate one meter or so for the foundation mattress, which will measure two meters in width, 50 cm in height, and have a length equal to that of the wall being planned. You can estimate this before breaking ground and then polish the design layout once you have completed the excavation. You will also need to decide at this point whether your gabion wall is to have a smooth face, or to have steps in its rise. In the example, I used steps of 10 cm width for each gabion row. Excavate the base to the point of undisturbed soils or bedrock if it is near the surface. The face will be unstable—or else you wouldn’t need a wall in the first place—so take care for wall caves. Don’t worry about them, as you will backfill and compact as your wall rises, but the first rule is to work safely. The exposed footprint must angle 6 degrees (or whatever your design is if you have reason to increase the batter angle). Since the foundation will be 2 meters wide, the outside floor surface must be 8 cm higher than the inside floor surface, the entire length smooth and even. Starting out Excavate base Cut enough gabions in half to situate them for a foundation. You will need half as many more to cut away the tops for the mattress baskets. Tie in tensor cables on 25 cm centers across the width of the mattress. For each open gabion, you will need to add six cables from front to back at the mid-point of the mattress rise. Fill with rocks, then sew the tops closed with galvanized wire. Nine tensors per cubic meter; 18 per gabion Sewing the top The mattress is twice the width of the gabion baskets to follow, and the centroid of the structure should ideally be situated slightly inward from the center of the mattress. Re-do all your numbers, taking into account any steps that you have in order to decide how to position your first row of baskets on top of the foundation. The internal tensor wires are critical to contain the rock without deforming the cages. In each gabion, you will tie in 18 tensor wires as shown in the drawing on 25 cm centers. But you will need to place the rock by hand, so you’ll want to add the tensors as you work so that you have room to work. Hand place the rock so that it is well settled and when full sew the cage tops closed with galvanized wire. Backfill and compact the space behind the first row of gabions. It will be tempting to use the excavated soil. Forego this temptation and haul in river sand for this compaction. You can mix this with excavated soil, but you need sand and gravel for best results. Repeat steps 6 and 7 consecutively with each new gabion level until you reach the top. Backfill Build it till it’s finished Groom Groom disturbed areas and plant verdiver or other deep-rooted plants in disturbed soils on the sides and manicillo or plants of your choice on shoulder. See the original article here... Tropical Deforestation: Hydrology ImplicationsDecember 18, 2017Blog Paul Collar Paul is a hydrogeologist and environmental engineer and the owner/operator of Osa Water Works. You may reach him at solutions@osawaterworks.com The most important process that native forests play in the water cycle is evapotranspiration, a process in which water is taken from land and introduced into the atmosphere through the agency of photosynthesis in trees. Large amounts of water respond predictably to convective pressures of the tropical sun to spawn native rains that are important contributors to yearly totals. Storm born precipitation blown in on weather fronts is also a large component of annual rainfall. But without the in situ rain factory of a tropical rain forest, it would cease to be one, and water would migrate elsewhere. Evaporation is responsible for transferring as much as 70% of the rain that falls in tropical rain forest to the atmosphere, much of which is returned as local rain, to be cycled again. The role that forests play in the equilibrium of water between the atmosphere and lithosphere, something that we cannot see but can feel and measure, cannot be overstated. Evapotranspiration is the 800 megaton gorilla in the tropical rain forest. Forests introduce other variables that play critically into the water cycle—beyond the vastness of evapotranspiration—that are the driving forces of terrestrial hydrology, what is left behind for riparian admirers everywhere, after the atmosphere sucks up its aliquot. The percolation of rainfall runoff into soils and the recharging of aquifers are facilitated by forest root systems, which provide openings in soil layers that allow infiltrating waters to search out the water table. But the forest itself is furthermore a giant repository of water. Humans are 60% water, trees, just 50%. Tropical rain forest soils are notoriously poor, and all the ecosystem’s nutrients are held in the biomass, which is why slash and burn is an effective pioneering approach in soils not natively apt for agriculture. Just as the forests are a repository of living nutrients, so too are they a repository of living water; 50% of their mass. Forests hold soils in check, and the streams draining standing forest are of an extraordinarily high quality as a result. Only scientists get to dabble in a perfect world, however, and in the civil engineer’s mission to intrude benevolently upon nature for favorable community outcomes, sometimes mistakes get made. Indeed initial assumptions in tropical forestry that forests increased downstream water flow and provided checks against floods turned out wrong. The societal implications of decades of forestry research provide a rough blueprint of the cause and effect relationships that exist between tropical hydrology and deforestation, at both the micro and macro scales. A few things we have learned along the way: Up to 70% of useable water resources exist as a result of forest capture of rain water. Forests hold soils in place and sustain high water quality in streams and rivers. The cutting of forests exposes soils and increases erosion, promoting the decline in downstream water quality and siltation in low-lying areas, plus the clogging of nearshore environments, including sensitive ecosystems like coral reefs. Formerly considered a guardian against devastating floods, contemporary science has found that forests really do not protect against downstream flooding at all. Forests hold water and release it slowly. Deforestation results in greater downstream water flow of lower quality. Preservation of forests results in increased infiltration and higher ground water levels and a more gradual release of high-quality water to downstream areas through springs and runoff. Water is neither created nor destroyed in the surface environment. It is simply moved around. Once fresh water is discharged to the ocean, its role in the water cycle becomes restricted to evaporation and weather systems and is forever lost to engineering aspirations for its productive use. Landslides present a scientific microcosm for understanding the relationship between water, soils and forests. The fresh soils exposed by slope failures are readily eroded by rains pounding their denuded surface. Runoff from these naturally-marred land surfaces is clogged with clay and sediment, and runoff bleeds chocolate rivulets into receiving streams. But landslides are needles in the haystacks of natural forests. Fire fires and anthropogenic deforestation produce circumstances analogous to landslides, however, and put soil erosion on steroids, swelling chocolate rivers with high turbid flows that in coastal settings sweep quickly to sea and thereby displace terrestrial water to the ocean, where it is no longer available for conventional human use and for good measure also contaminates coastal environments with suspended clay and silt. For better or for worse, Humanity requires vast amounts of fresh water to sustain not just its potable demand but also agriculture and food production. As a result, mankind shall always face the challenge of how best to manage its water and forestry resources, not just for the protection of wild areas that warrant protection for the biodiversity they harbor, but also for the protection of human needs, both for potable needs and for the vastly greater demand that comes from agricultural requirements to sustain the human appetite for three squares a day. Setting aside the effects on purely technocratic considerations like water supply, however, the sediment that is eroded from deforested lands has dramatic downstream consequences. Changes in sedimentation patterns affect river channels and increase the frequency and severity of devastating floods. While flood waters historically introduce organic nutrients that increase agricultural productivity in later years, the sediment eroded from denuded forests is organic poor and depresses agricultural productivity, leading to greater reliance on agrochemicals to sustain production. And in places like the Osa Peninsula, with nearby fertile coastlines teeming with life, the sediment eroded from deforested plots overwhelms some sea life, particularly among corals and other benthic invertebrates which, unlike fish, cannot swim away from the threat. Corals comprise a foundation of a vital ecosystem upon which a large range of marine organisms depend for a living. As coral productivity is pounded from unnaturally high sediment loads from land disturbances and from agrochemical pollution resulting from farmers’ responses to declined soil fertility, the anastomosing effects boomerang up the food chain to quickly curtail the fisheries upon which coastal communities depend as a source of both food and commerce. In the Golfo Dulce sediment loading from the combined effects of deforestation and gold mining has wiped out framework corals, and researchers have written off corals for this remarkable body of water, their state of decline irreversible. Researchers point out that increased fresh water flows have also affected the corals adversely. Whether this is due to increased runoff as a result of deforestation or changes in precipitation patterns is a question for further investigation. Absent a single further penny in research, however, decades of forest hydrology research and human experience has shown that forests are integral to the water cycle and key to environmental sustainability of the places they exist. Forests capture water and recharge aquifers, purify and discharge high quality water, are themselves repositories of water, and through photosynthesis exchange vast amounts of water with the atmosphere to drive weather patterns. Forests are enormous attenuators that keep our surface environment in a semblance of balance in a Koyaanisqatsi universe. The take-away? It can never hurt to plant a tree. See the original article here... Where does all this gold come from?December 18, 2017BlogWhere does all this gold come from? By: Paul Collar Paul is a hydrogeologist and environmental engineer and the owner/operator of Osa Water Works. You may reach him at solutions@osawaterworks.com All that is gold does not glitter Not all those who wander are lost The old that is strong does not wither Deep roots are not reached by the frost. JRR Tolkien From 1981 to 1989, during the Osa Peninsula’s famous gold rush, some 4800 kilograms of the precious metal was mined from its placers. This compares to an estimated 1800 kg from the Tilarán/Aguacate gold district in the same time frame1. The Cerritos District in the Curtis Region of San Carlos near the Nicaraguan border is the third known occurrence of gold inside Costa Rica. Cerritos has never been mined and is in fact the subject of an ongoing World Bank arbitration between the Canadian company Infinito Gold, Ltd and the nation of Costa Rica2. Infinito seeks reimbursement of its $93 million investment (down from its original demand of $1 billion in lost projected profits) after Costa Rica declined the exploitation concession required to legally mine. Osa, Tilaran/Aguacate, Crucitas: nowhere else in Costa Rica is gold known to occur in greater than trace amounts. In both the Tilarán/Aguacate and Cerritos districts gold occurs in low-temperature primary quartz veins that fill fractures or in primary veinlets disseminated throughout hard rock. The hydrothermal mineralization of both is thought to result from the heat and metal source of a cooling pluton in the tectonically active subsurface. In both cases, mining requires the breaking of solid rock and physical extraction of ore and its subsequent physical and chemical processing. In the Tilarán Cordillera, hand miners used drift tunnels underground to follow ore veins during artisanal mining that dates from the early XIXth Century. Recent mining operations include the Bellavista Mine, an open-pit mine that operated from 2005 to 2007. In both tunnel and open-pit mining, primary hard-rock gold ore, whether extracted with chisels and sledges or dynamite and excavators, must be first crushed and milled and then concentrated chemically with cyanide for leaching gold from ore heaps and tailings piles and native mercury to subsequently recover and concentrate the leached gold. Two more toxic substances than cyanide and mercury are rarely mentioned in a single sentence whose subject matter is not toxicity itself. Hard-rock gold mining and refinement have catastrophic environmental consequences, no matter where it is practiced. It is not an activity compatible with any definition of environmental sustainability, and it never will be. At Crucitas, the disseminated nature of the gold meant that strip mining by Infinito was to be the only viable extraction method. With Costa Rica’s environmental patience already pushed to its breaking point over the 2007 landslide and cyanide spill at Bellavista, the Crucitas venture never got off the ground and never had a chance. In fact, Costa Rica’s law forbidding strip mining dates to 2002, and the only reason Bellavista was allowed to open in 2005 was that the extraction concession had been issued years before the new law was passed. With Costa Rica’s future joined at the hip with the environment and eco-tourism, hard-rock mining and its environmentally destructive methods of both mining and chemical extraction made it unlikely then and make it unlikely today to ever be jumpstarted again. The gold that forms Costa Rica’s most important gold region, the Osa / Burica gold district, is, however, not primary gold, but secondary, placer gold. It is native gold that has already eroded from a primary source and been concentrated by water and topography. The gold mined in the Osa is the native element itself and requires no further refinement during mining. Gold is, after all, impervious to chemical alteration or dissolution, so it stays in the environment forever. It is the densest substance that occurs naturally on the earth’s surface, so it prefers to sink into low spots and is for this reason readily concentrated by natural geomorphic processes. No chemicals are needed or used, and mining methods include the use of sluice boxes and wash plants to mechanically concentrate the loose gold in soils, regolith, ancient river and beach terraces, channel deposits, flood plains, active river channels and beach sands. Neither hard-rock tunneling nor strip mining is required, and placer gold mining carries none of the environmental threats of hard-rock gold. Another key difference that has left a long impact on Osa society and culture is that placer gold can be worked by a single miner or in small groups of partners or cooperatives and does not absolutely require machinery or substantial capital investment to achieve results. In Tilarán, collective effort, capital, and ingenuity were required to extract and concentrate gold even in the early days. In the Osa all that was needed was a single man’s determination, grit and obstinacy in the face of overwhelming nature. The primary gold districts of Tilarán and Crucitas carry placer gold in their local rivers and streams just like primary gold occurrences do everywhere. The converse is also usually true: nearly all placer districts are accompanied by a known primary gold source from which the placer gold was eroded. But the Osa / Burica gold district is an exception. Here placer gold is abundant and has been mined by modern man for ninety years and in pre-Colombian time for at least 2000 years without a single primary hard-rock gold vein ever known to be discovered. Here we have lots of secondary gold but no trace of the primary. This begs a question that has been keeping economic geologists and exploration geochemists awake at night for the past 90 years. Where does all this gold come from? See my literature review3 on the subject for details, but to summarize what we think we know: Shatwell4 points out that porphyry-type polymetallic deposits are common in the Talamanca Mountains, and that these are the most likely source for the Osa gold, that it was eroded from the Talamancas and transported by river systems before the opening of the Golfo Dulce to where we find it today. This theory suggests that Osa and Tilarán/Crucitas gold have similar hydrothermal origins from cooling plutons of an intermediate lithology type, somewhere between basalt and granite. Kriz4 and Berrangé5 say “not so fast; the gold couldn’t have come from that far away.” Berrangé pointed to crystalline gold with intertwined quartz crystals in Osa nuggets that could not have traveled far or they would be broken apart and rounded. He offered up the kilogram-plus mega-nuggets of Violines Island as proof positive that the gold was local and could hardly have rolled down rivers from a source 20 or 30 miles away. Kriz insisted that the gold came instead from a rock overlying today’s land surface that has since been completely eroded away. Berrangé did not agree, insisting the gold had to come from quartz veins in the Nicoya Complex rocks, the actual basement rock upon which these placers form today. So, Kriz says the primary source is eroded away; Berrangé says it remains undiscovered in hard rock beneath 30 meters or so of regolith and soils. Both theories have holes: if all the gold is derived from rock that is beneath our feet, then why after ninety years of mining has the primary never been found? And if the entire primary source was in an overlying unit that was completely eroded away, then why do we recover freshly crystallized vein material in some upland nuggets in the Rancho Quemado region and other places on the peninsula? By comparing the ratio of gold to silver in nugget and vein gold from Osa, Tilarán, and Crucitas ore bodies, Berrangé showed that the gold in the Osa has a dramatically higher Au:Ag ratio and is quite different from the native alloy found in Tilarán and Crucitas ore. The latter two he concluded were quite similar, as would be expected from their common metallogenesis from intermediate rocks inland from the leading edge of the overriding Caribbean plate. Osa gold is dramatically more pure and has a different trace metal distribution, evidence of an origin from the hydrothermal veins of not intermediate plutons like Talamanca and Tilaran rocks at all, but mafic basalt-family rocks, consistent with the composition of both the Nicoya Complex oceanic rocks thrust on land—ophiolites to geologists—as well as the relatively young basalt occurrences shown in blue in the Costa Rica geologic map of Tournon and Alvarado7. Whatever the ultimate primary source of gold may be, Berrangé made the most comprehensive classification of the Osa placer types. It shows a series of placer types likely familiar to most of those with local hand- or commercial mining experience. While most prospecting is done with bar, pick, shovel, pan, and sluice box, Violines Island is one of the few places in the world—like parts of Australia—where loose gold occurs in nuggets large enough that it may be successfully prospected with metal detectors. A friend of mine, Ray Smith, formerly of Golfito and now guiding back-country big-game hunts in Montana, found a 76-gram nugget in the late nineties using a metal detector in the Guerra region, right across the Sierpe River from Violines. But for those that tire of the search for native gold, rumor has it that Sir Francis Drake left a considerable treasure buried along the shores of the bay along the Osa’s northwest coast that today carries his name. So long as gold remains within reach of ordinary men, its presence—whether natural or hidden by pirates—shall likely always inspire some to defy the mosquitoes and leaches, to suffer the rain and disease, to weather the heat and oppressive wetness, and to gallantly suffer all the miseries attendant upon its pursuit to continue prospecting and hand-mining the gold of paradise. 1 La Nacion, 2013: Península de Osa: el lugar donde mas abunda el oro en Costa Rica. 2. Tico Times, 2015, July 15: Gold mining company that sued Costa Rica files for bankruptcy Collar, 1994: The Geology and Distribution of Gold, Osa Peninsula, Costa Rica, a Literature Review; MUDESA private report, reprinted: http://www.soldeosa.com/editorial/07-21-gold-literature-review.htm 4 Shatwell, 2004: Subducted Ridges, Magmas, Differential Uplift, and gold Deposits: Examples from Central and south America; the Ishiyara Symposium: Granites and Associated Metallogenesis; Geoscience Australia. 5 Kriz, 1990: Tectonic evolution and origin of the Golfo Dulce gold placers in southern Costa Rica; Revista Geologica de Centro America; v. 11, p. 27. 6 Berrangé, 1992: Gold from the Golfo Dulce Placer Province, Southern Costa Rica. Rev. Geol. Am Central, 14: 13-37 7 Tournon and Alvarado, 1995: Mapa Geologico de Costa Rica, escala 1:500,000; folleto explicativo, 79 paginas, Editorial Tecnologico de Cartago, Costa Rica. See the original article here ... Stomach Cancer in Costa Rica: What are the Odds?December 18, 2017BlogStomach Cancer in Costa Rica: What are the Odds? By: Paul Collar Paul is a hydrogeologist and environmental engineer and the owner/operator of Osa Water Works. You may reach him at solutions@osawaterworks.com The incidence of gastric cancer varies widely, from 28.3 cases / 100,000 people in Mongolia to 0.78 / 100,000 in Mozambique. That is a ginormous planetary variance of nearly two orders of magnitude! At 17.3/100K Costa Rica ranked 10 th for women and 12 th for men in 2014 according to the World Cancer Research Fund International. In 1998 Costa Rica was 4 th after North and South Korea and Japan in the incidence of this 5 th most common type of cancer. Stomach cancer is documented in the written record since 3000 BC. Until the last decade of the 19 th Century when lung cancer overtook its crown, stomach cancer was the most widespread form of human cancer and had been throughout all of human history. We were meeting to discuss non-medical business when I sprang the question on Dr. Randall Umaña Villalobos, Resident Doctor at the Clínica de Puerto Jiménez, so he wasn’t expecting it: “So why, Doctor Umaña, is the incidence of gastric cancer so high in Costa Rica?” “There are many risk factors,” he said, “that make it hard to isolate causes. Getting cancer is like winning the lottery,” he said, “only in reverse. In Costa Rica it is thought that our high incidence is likely related to sanitation and hygiene; it is more prevalent, after all, in the developing world.” Except for Africa. The Dark Continent at last assessment was still in the developing world class of nations. Yet it has the lowest regional rates of stomach cancer on the planet. Until 1982, white-bread doughboy gastro-oncologists still counted spicy foods as a risk factor for gastric cancer: of course the Koreans and Japanese were susceptible: look at what they ate! But that very year the bacterium Helicobacter pylori was isolated, cultured and classified, and the medical community quickly seized on and confirmed this unrecognized interloper as a risk factor for gastritis, peptic ulcers, and indeed some varieties of stomach cancer. A raft of research and a number of conclusive findings followed. It turned into a sufficiently big deal over the next 33 years that just last year, Australian researchers Barry Marshall and Robin Warren were awarded the Nobel Prize in Physiology or Medicine for its discovery. It turns out that only 50% of the world’s population is infected by H. pylori. Miranda and others (1998) found in the Poás and Puriscal regions of Costa Rica an 83 and 82% infection rate respectively. The VI International Helicobacter pylori Symposium was held in San Jose, Costa Rica in 2014, where it was revealed that sub-strains of H. pylori correlate with substantially different health effects. The less virulent strain is common to, ironically, Africa, and the more virulent strain is prevalent in Asia and South America. In Costa Rica, La Nación (2015) reports that 5-15% of the infected population can expect to develop medical complications. Otzi was a Neolithic denizen that died from an arrow wound in the high Alps 5000 years ago and was mummified by the snow. Researchers have since detected the presence of H. pylori in his stomach. Helicobacter pylori is not a native resident of human flora. It is an opportunistic bacterium that enters the body through ingestion, typically in childhood or adolescence, and persists outside of treatment in the mucus of the upper stomach for the rest of the subject’s life. In most cases its presence does not cause disease and in some studies its presence has been shown to have a prophylactic effect against other maladies, including asthma of all things, and even some types of stomach cancers themselves. In 2004, Fujimura et al tested environmental samples from a Japanese region with a particularly high H. pylori infection rate and discovered that the bacterium was for all practical purposes ubiquitous in the surface environment. Since the bacterium is present in native waters and in farmed soils and since the bacterium infects through ingestion, they showed that contaminated water and food are an unambiguous vector of infection. There is a chicken and egg quality, however, to the findings: did the environment have high bacteria because of the prevalence of human infection, or was the environment causing the infection? In practical terms it does not matter. The bacterium is in the environment and infects through ingestion. To avoid infection, therefore, we must guarantee as a first line of defense that drinking water supplies exclude this pathogen. Costa Rica is a nation with a prolific abundance of water, and Ticos have for most of recorded history and all of prehistory gotten water from springs and highland streams and shallow wells and only in recent decades bumped up against such novelties as municipal water systems. In all fairness, Costa Rica stepped up to that plate many years ago and is one of the few Latin American nations that has fully potable water supply as national policy. As a water engineer, I warn off-grid folks that due to the ubiquity of the protozoan Giardia lamblia, all surface water in this nation and for all practical purposes anywhere on the planet with wild or domesticated animals should be considered contaminated by this particularly widespread sponsor of a rough patch for first timers: amoebic dysentery, or beaver fever if you prefer. I have found from testing across 16 years that hard-rock and saprolite springs in Costa Rica are in my experience universally free of fecal coliform and are of superlative water quality from a physicchemical perspective as well. But contact with the surface environment quickly contaminates these pristine sources with zillions of biospheric pathogens, and proper intake designs that protect against this contamination are in practice seldom used and irregularly maintained, a quirk unseen in most parts of the world, where water is less abundant. In Costa Rica, the predominant malefactor is Giardia, and most of us have developed a physiologic tolerance from a lifetime of exposure. Like H. pylori, Giardia also resides opportunistically in infected subjects unless and until intervened with a proper antibiotic regimen. The indicator organism fecal coliform, enshrined by the World Health Organization as the planet’s standard-bearer for water potability, provides for a low-cost test to confirm the absence of intestinaltract waterborne parasites. However, unlike microbes that transmit cholera, hepatitis-A, typhus, typhoid fever, amoebic and bacterial dysentery, and all kinds of other bad nasties, Helicobacter pylori does not live in either of the intestines but in the upper stomach. It is an aerobe that requires oxygen to live. Oxygen is poison to the anaerobic pathogens that dwell in the intestinal tracts of mammals and birds. The WHO guidelines for water potability is non-detection of fecal coliform. Any detection whatsoever classifies the water as non-potable without treatment. Costa Rica uses this standard for its own national water-quality policy. So does the US. All countries do. But fecal coliform is not an indicator of H. pylori and says nothing at all about its possible presence or absence in surface waters. So I called up the head of the microbiology division at Laboratorios Agrotec, the lab I rely on for minor and trace ion hydrochemistry and biological analysis. “I’d have to prepare or order a culture medium probably,” Fabricio demurred. “It’s not something we routinely do, but it’s not rocket science.” After a telephone survey no private labs that we contacted offered H. pylori analyses on even human fluids or biopsy tissue, far less water or soil samples. “They do it in public institutions,” we were told, “when requested by doctors at clinics from biopsies.” Dr. Umaña says it would be unusual inside national institutional medicine to call for H. pylori tests, or to treat patients to rid them of the infection. With 80% of the population already infected, a positive detection would appear to simply be a confirmation of the obvious. “And if I had an H. pylori infection,” I said, “and wanted to get rid of it,” I asked him, “what would I have to do?” “No single medication will treat it,” he said. “But the treatment regimen is two antibiotics, one a single dose, the other across seven days, assisted with a medication that reduces stomach acidity.” So . . . * H. pylori infection has been incontrovertibly linked with stomach cancer. *Costa Rica has a high incidence of stomach cancer. * Seven out of ten Ticos have the H. pylori infection, which results from oral ingestion, usually as children or teenagers. *The strain of H. pylori present in Costa Rica is the most likely to cause gastric maladies. * Costa Rica has a disproportionate rural dependence on haphazard home water supply systems from natural sources (springs, streams, shallow wells) where H. pylori is known to exist. Could it be possible there is a relation here? Might we correct in future epidemiological research for the effects of: 1) genetics; 2) age; 3) alcohol and tobacco consumption; 4) salt intake; and 5) exercise and lifestyle and dial down on the role that environmental H. pylori actually plays in our heightened national vulnerability to stomach cancer? I think this dialing down is in this nation’s and indeed humanity’s near future. In the meantime, it seems reasonable to assume that our water supply is the first line of defense against infection at any age but particularly for the more vulnerable young. Both ultraviolet and chlorine kill all microbes, aerobic and anaerobic, pathogens and innocuous alike. Ultraviolet light is a form of energy located on the electromagnetic spectrum just below the visible range of light that is toxic to microbes upon exposure. Chlorine is an element that remains in the water after contact, a chemical if you prefer, and is toxic to all life and is a known human carcinogen. Both UV and chlorine make the water indisputably safe from microbial contamination, but chlorine carries a latent risk factor. In town, the water is chlorinated. But for everyone off-grid, ultraviolet disinfection is an inexpensive water purification solution that is non-chemical, has no known adverse side effects, and guarantees your family against all microbial and viral pathogens, including the one we have not yet properly recognized and indoctrinated into the hallowed hall of gastro-enteric bad boys: Helicobacter pylori. See the original article here ...
