! ! Assessment of greywater parameters throughout treatment sites at the Monteverde Institute and Los Pinos Hotel Alexandra Arriaga Covarrubias University of California, Santa Cruz UCEAP Spring 2018 08 June 2018 ____________ _________________________________________________________________ ABSTRACT Water is crucial in all aspects of lif e; therefore, the way in which we treat water directly impacts our future. Greywater result s from huma ns' interaction with water in their everyday li fe , but what we do with th e greywater can have various effects on the environment and us. This study tests the effectiveness of two primary grey water treatment systems at Los Pinos Hotel and the Monteverde Institute in Monteverde, Costa Rica. Six sections of each system were tested for a variety of parameters: temperature, dissolved oxygen, salinity, conductivity, total dissolved solids, and pH. Although both locations use preliminary and primary treatment systems for their greywater, the end values of the six parameters varied per site. Los Pinos Hotel had a significant increase in salinity , conductivity, and total dissolved solids and a significant decrease in dissolved oxygen. While, the Monteverde Institute had a s ignificant increase in temperature and a s ignificant decrease in dissolved oxygen and pH . The differences in the results could be due to the difference s in grey water quantity and quality that flow throughout the systems. Los Pinos Hotel system only treats laundry water; whereas, the Monteverde Institute treats grey water from their kitchen , bathroom sinks, and showers. The changes in the greywaters from start to end indicate the effects that Los Pinos and the Monteverde institute have on their environment. EvaluaciÂ—n de parÂ‡metros de aguas grises en sitios de tratamiento en el Instituto Monteverde y el Hotel Los Pinos RESUMEN El agua es crucial en todos los aspectos de la vida; por lo tanto, la forma en que tratamos el agua impacta directamente en nuestro futuro. Las aguas grises son el resultado de la interacciÂ—n de los seres humanos con el agua en su vida cotidiana, pero lo que hacemos con las aguas grises puede tener diversos efectos en el medio ambiente y en nosotros mismos. Este estudio prueba la efectividad de dos sistemas primarios de tratamiento de aguas grises en el Hotel Los Pinos y el Instituto Monteverde en Monteverde, Costa Rica. AnalicÂŽ seis secciones de cada sistema al medir una variedad de parÂ‡metros: temperatura, oxÂ’geno disuelto, sa linidad, conductividad, sÂ—lidos totales disueltos y pH. Aunque ambos lugares utilizan sistemas de tratamiento preliminar y primario para sus aguas grises, los valores finales de los seis parÂ‡metros variaron por sitio. El Hotel Los Pinos tuvo un aumento sig nificativo en la salinidad, conductividad y sÂ—lidos totales disueltos y una disminuciÂ—n significativa en el oxÂ’geno disuelto. Por otro lado, el Instituto Monteverde tuvo un aumento significativo en la temperatura y una disminuciÂ—n significativa en el oxÂ’ge no disuelto y el pH. Las diferencias en los resultados podrÂ’an deberse a las diferencias en la cantidad y calidad de aguas grises que fluyen a lo largo de los sistemas. El sistema del Hotel Los Pinos solo trata el agua de lavanderÂ’a; mientras que el Instit uto Monteverde trata las aguas grises de la cocina, lavabos y duchas. Los cambios en las aguas grises de principio a fin indican los efectos que Los Pinos y el instituto Monteverde tienen en el ambiente.
Assessment of greywater parameters throughout treatment sites Arriaga 2 ! ! Water is life. This natural elem ent interacts with all biotic organisms and abiotic objects on Earth. Water has a key role in the survival, reproduction, and decomposition of life. From aquatic organisms, whose entire existence is in water, to human beings whose everyday lives involve water. For thousands of years, humans have manipulated and diverted water to areas where water does not occur naturally (Sklivaniotis and Angelakis, 2006). This has allowed for the existence of civilizations that are not directly next to a source of water. However, as human p opulations continue to develop , build, and prosper, their water needs continue to increase. As populations grow , more water needs to be diverted for human use and consumption ; therefore, less water is available to the surrounding ecosystems (Jordan, 2015 ). Although a lot of water is taken from the environment, some is returned. This water is not consumed but rather used. The used water is separated into two categories: grey water and black water. Grey water is rain water that has encountered human debris o r used water from sinks, showers, and washing machines . Grey water does not contain feces or other human excretory waste (Jefferson et al, 2004). Black water is any water that has encountered any kind of human waste or animal feces. In some areas of the wo rld, such as California, water undergoes an extensive and pricey treatment process before it is distributed to the population. The treatments can include methods such as bleaching, reverse osmosis, and other processes that make water potable to a certain s et of standards (Walker and Stanford, 2017). In California, grey and black water is also treated before being returned to the environment, but to different standards than potable water (Water Education Foundation, 2018). In Costa Rica, septic tanks are us ed to hold black water (toilet water) before it is transferred to a treatment plant. In some rural areas, d ue to limited space, t icos are advised to dispose of their grey water directly into their backyards, roads, or rivers to reduce water build up and prevent leaking in the septic tanks (Jackson, 2017). This disposal method pollutes the surrounding water sources and environment; as well as, threatens the public health of the community. When untreated grey water is dumped into the environment, it can al ter soil composition, change pH levels in water or soil, and deposit chemicals into the ecosystems of other organisms (Morel and Diener 2006). However, besides a ffecting the environment, grey water is a w ater source that can potentially be filtered and reu sed for potable or non potable human use. In Costa Rica, on average, approximately 187 liters of water per day are used by each person. About 85% of that water becomes greywater and only 4 % of that greywater gets treated (Coler, 2015) . Not only would Costa Rica benefit from the potential reuse of grey water, but so would ecosystems and the half of the world's population that does not have access to clean water (Bates, 2014). The more water that is reused, the more that is available for use and the less that needs to be taken out of the environment. By Costa Rica's Ley de Aguas (water law ) , it is required that all households and businesses treat their greywater; however, in most places, the law is not enforced, especially for households (Newell et al, 2005). In theory, this accountability allows Costa Rica ns to reduce their impact on the surrounding flora and fauna. I n the Monteverde and Santa Elena area, water is diverted into the se town s from the Cerro Amigos Watershed in the Bosqu Et erno SA ( Bosqu Eterno, 2018). Due to the ecological mission of these town s , a variety of business and households try their best to abide by the water laws ; although, i t is more common for businesses , rather than households, to have a grey water system in pla c e. Certain aspects of the greywater systems can be similar throughout different sites , but the format usually varies. For example, biogardens are commonly used to treat grey water. This system uses a variety of plants known to have water cleaning properties and is se t up so that water can flow through the roots of the plants
Assessment of greywater parameters throughout treatment sites Arriaga 3 ! ! and get cleaned as it passes (Appendix A ) . I wa s intereste d in understanding if different greywater formats impact the results of the greywater , specifically temperature, dissolved oxygen (DO), salinity, conductivity, total dissolved solids (TDS), and pH. Therefore, I pose the question, to what extent are the parameters of greywater changing before, during, and after going through the filtering systems at Los P inos Hotel and the Monteverde Institute? Answering this question can help these businesses understand if their greywater systems are abiding by the law, but more importantly, how they are impacting their surrounding environment. MATERIALS & METHODS I tested the temperature, dissolved oxygen (DO), salinity, conductivity, total dissolved solids (TDS), pH, and grease/soap build up in the grey water throughout the respective treatment sites to note if these characteristics were changing. Sites: The first site, Los Pinos Hotel, utilizes a three section system to filter the hotel's laundry water. The first section is divided into four main parts: (1) a mesh filter that catches solids in the water; (2) a stagnant area of water where the soap floats to the top and the rest continue below; (3) a pipe that delivers the water below into a serpentine tank; (4) a set of four switchbacks that allow the water to separate from the soap at a slower and more thorough rate (Appendix B). The water then travels to the second section, a b iogarden, where water leaks out of two surface tubes allowing the water to seep down through various layers of sediment and roots that further filter the water . A pipe then moves the filtered water into a h olding tank where the wate r remains stagnant as it slowly drains into the garden at Los Pinos. (Appe ndix C). The first section is covered by a large mesh top, the pipes of the second section are completely exposed, and the third section is also only covered by a mesh top. This system is cleaned twice a week. I took samples at t he four p arts of the first section, at the water leaking out of the pipes in the second section, and of the stagnant water in the third section . The second site, the Monteverde Institute, also consists of a three section system that filters their collective grey water from the kitchen sink, bathroom sinks, and showers. Though the systems are similar, this system is smaller and less exposed to the outside environment. The first section cons ists of 3 main parts that deal with only the kitchen water: (1) a mesh filter that collects solids, (2) a second trench that allows for separation of fats and oils; (3) a third trench that gives the water more time for separation. The water then exits to a pipe and reaches the second section where it is mixed with the bathroom grey water. These are two large tanks that have varying levels of sedimentation that filter the water through (Appendix D ) . The filtered water then moves to a two section biogarden be fore being released to a grass patch at the Instit ute . There are vertical pipes at the beginning, middle, and end of both halves of the biogarden that can be opened to see the amount of water flowing through the biogarden. Most days, the water did not reac h the second half of the biogarden; therefore, I focused on the first half for my study (Appendix E) . The water did not reach the second half due to a low quantity of water in the system. When there are not many visitors , not enough water flows through the system to reach the second biogarden . The first section is covered by a metal top, the bins also have air tight plastic tops, and the pipes of the third section are deep underground. This system is cleaned once a week. I took samples at the three part s of the first section, at one of the bins from the second section, and at the first pipe and last pipe of the first half of the biogarden . Methodology
Assessment of greywater parameters throughout treatment sites Arriaga 4 ! ! Using the YSI 556 Multi Probe System , a device used to calculate various parameters in a liquid solution (Appendix F) , I tested grey water quality at two sites. From 13 19 of May 2 018, I visited Los Pinos Hotel (LPH) and the Monteverde Institute (MVI) and tested their greywater systems for six days, once in the morning between 8 10 AM and once in the afternoon between 2 4 PM. Each time I went, I measured the temperature, dissolved oxygen (DO), salinity, conductivity, total dissolved solids (TDS), and pH using the YSI. I measured these parameters because they were specified in the water laws or because the y are indicators of the effectiveness of greywater cleaning system. For the first three days at Los Pinos Hotel, I directly inserted the YSI into the six various points to collect the data. For the last three days, I collected water samples using sampl ing cups that I would fill to the brim, so that the levels of dissolved oxygen were not affected. I would then pour the samples into another container and use the YSI at the Monteverde Institute Lab. I made this change because of transportation issues movi ng the YSI between th e Monteverde Institute and Los Pinos Hotel. For the Monteverde Institute, I tested the six points directly on site for all six days. For every point tested, at both locations, I allowed the YSI to calibrate for one minute before recor ding the data. Usually, after one minute, the only parameter changing was DO. Between each test, I rinsed the probe with clean water. Occasionally , I would wipe it down if too much grease was on it. This was so that the values were not contaminated by the previous ones . Also, every afternoon for the six days, I took a water sample from the six main areas for both sites. I would let th ese sample s sit , undisturbed, at the lab for about 24 hours and then I would measure the band of grease or soap that formed at the top. I measured this to the millimeter and took note of the clearness of the water (Appendix G). Statistical Analysis I statistically analyzed the data using 1 way ANOVA and Tuk ey Kramer pair wise analysis. The data is presented by parameter per site using a Box and Whisker Graph. The pH plot graphs do not have an average line because averages for pH need to be calculated differently. An online calculating system was used to get the values. The YSI does not have units for the salinity values. RESULTS Los Pinos Hotel had significant difference in the before and after dissolved oxygen, salinity, conductivity, and total dissolve d solids . T he Monteverde Institute had a significant change in temperature , dissolved oxygen and pH. On average, both the LPH and the MVI had a visible increase in water visibility from beginning of their systems to the end. The following Box and Whisker plot graphs include two extremes (the whiskers) that represent the maximum and minimum values, respectively . The outline of the box represents the first and third quartile and the inner line represents the median. The outliers are not within the box. The means are connected with a horizontal line. Bars conne cted with the same letter are not significantly different . If no letters are present above the graphs, there was no significant differences amongst any samples. Each sample for both locations has n=12. Temperature : The change in temperature at the Monte verde Institute was significantly higher by the end of the treatment (Fig 1; F=2.68, df =5, p=0.02 8 ) with an initial median of 20.3 7 ! C and a final median of 21.04 ! C . The temperature at Los Pinos did not significantly change by the end with an initial median of 21.04 ! C and a final median of 21.04 ! C .
Assessment of greywater parameters throughout treatment sites Arriaga 5 ! ! ! Figure 1: Monteverde Institute Temperature readings for each sample site for the duration of the project. Sample F is significantly higher than sam ples D and E. Sample F is not significantly different than sample A ( F=2.68, df =5, p=0.0276) Figure 2: Los Pinos Temperature readings for each sample site for the duration of the project. Samples A F are not significantly different ( F=0.86, df =5, p=0.5 ) Dissolved Oxygen: The change in dissolved oxygen throughout the Monteverde Institute was significantly lower by the end of the treatment (Fig 3; F=11.49, df =5, p<0.0001) with an initial median of 6.08 mg/L and a final median of 0.26 mg/L . The dissolved oxygen at Los Pinos was also significantly lower by the end (Fig 4; F=55.30, df =5, p<.0001) with an initial median of 7.79 mg/L and a final me d ian of 0.78 mg/L .
Assessment of greywater parameters throughout treatment sites Arriaga 6 ! ! Figure 3: Monteverde Institute d issolved o xygen readings for each sample site for the duration of the project. There are significant differences amongst samples, sample F is significantly lower than sample A (F=11.49, df =5, p<0.0001) Figure 4: Los Pinos di ssolved o xygen readings for each sample site for the duration of the project. There are significant differences amongst samples, sample F is significantly lower than sample A (F=55.30, df =5, p<.0001) Salinity: The change in salinity throughout the Monteverde Institute was not significantly different by the end with an initial median of 0.08 and a final median of 0.10. The salinity at Los Pinos significantly increased by the end (Fig 6; F=5.59, df =5, p=0.0002) wi th an initial median of 0.07 and a final median of 0.1 1 . ! Figure 5: The Monteverde Institute salinity readings for each sample site for the duration of the project. Samples are no significantly different (F=0.51, df =5, p=0.77 )
Assessment of greywater parameters throughout treatment sites Arriaga 7 ! ! Figure 6: Los Pinos s alinity readings for each sample site for the duration of the project. There are significant differences amongst samples, s ample F is significantly higher than samples ( F=5.59, df =5, p=0.0002) Cond uctivity: The change in conductivity at the Monteverde Institute was not significantly different by the end of the treatment with an initial median of 153.50 Âµ S/cm and a final median of 196.00 Âµ S/cm . The conductivity at Los Pinos significantly increased (Fig 8; F=5.68, df =5, p=0.0002) with an initial median of 145.00 Âµ S/cm and a final median of 210.00 Âµ S/cm . Figure 7: Monteverde Institute c onductivity readings for each sample site for the duration of the project. Samples are not significantly different ( F=0.55, df =5, p=0.74 )
Assessment of greywater parameters throughout treatment sites Arriaga 8 ! ! Figure 8: Los Pinos co nductivity readings for each sample site for the duration of the project. There are significant differences amongst samples, s ample F is significantly higher than sample A ( F=5.68, df =5, p=0.0002) Total Disso lved Solids: The change in total dissolved solids at the Monteverde Institute was not significantly different by the end of the treatment with an initial median of 0.110 g/L and a final median of 0.140 g/L . The total dissolved solids at Los Pinos significantly increased (Fig 10; F=5.82, df =5, p=0.0001) with an initial median of 0.100 g/L and a final median of 0.150 g/L . Figure 9: Monteverde Institute total dissolved s olids readings for each sample site for the duration of the project. Samples a re not significantly different (F=0.51, df =5, p=0.77 )
Assessment of greywater parameters throughout treatment sites Arriaga 9 ! ! Figure 10: Los Pinos t otal d issolved s olids readings for each sample site for the duration of the project. There are significant differences amongst samples. Sample F is significantly higher than sample A ( F=5.82, df =5, p=0.0001) pH: The change in pH throughout the system at the Monteverde Institute was significantly different (Fig 11; F=4.22, df =5, p=0.002 ) with a median of 5.29 before the treatment and a median of 5.3 1 at the end of the treatment. Whereas the pH at Los Pinos was not significantly different with a median of 6. 29 and 7.47 b efore the treatment and a median of 6.79 at the end of the treatment. The grey water became slightly more basic, but not significant enough. Figure 11: Monteverde Institute pH readings for each sample site for the duration of the project. There are significant differences amongs t sample. Sample F is not significantly different than sample A (F=4.22, df =5, p=0.0020)
Assessment of greywater parameters throughout treatment sites Arriaga 10 ! ! Figure 12: Los Pinos pH readings for each sample site for the duration of the project. Samples are not significantly different (F=0.4170, df =5, p=0.8357) Both sites were within the Costa Rican Law standards for temperatur e and pH. Both were not within the law standards for total dissolved solids. The values for both sites do not meet the standards for drinking water. Both had no significant difference from initial value to final value in temperature, conductivity and pH (Table 1) Table 1: Comparing the initial and final values at Los Pinos (LP) and the Monteverde Institute (MVI) wit h potable water values and the C osta Rican law standards. Parameter Initial Value LP Final Value LP Significance Potable Water Value Costa Rican Law Standard Initial Value MVI F i nal Value MVI Significance Temperature ! C 21.02 21.25 NO 37 15 40 20.66 21.16 NO Dissolved Oxygen (mg/L) 7.48 0.81 LOWER 0 2 N/A 5.07 0.62 LOWER Salinity 0.08 0.11 HIGHER 0 N/A 0.09 0.10 N O Conductivity ( Âµ S/c m) 154.23 213.12 NO 50 500 N/A 176.71 209.77 NO
Assessment of greywater parameters throughout treatment sites Arriaga 11 ! ! Total Dissolved Solids (g/L) 0.11 0.15 HIGHER <1 <0.05 0.12 0.15 NO pH 6. 29, 7.47 6.79 NO 6 8 5 9 5. 2 9 5.3 1 NO There was an overall visible clarity of the water from the initial grey water to the final greywater after it passed through the filtration systems. At Los Pinos, the water was equally merkier , clearer, or the same from the beginning of the system to the end. All the samples had similar size soap/ grease bands and clarity of water (Appendix H). At the Monteverde Institute, the water was clearer at the end of the filtration system for most of th e days. The band of grease/ soap changed significantly amongst the samples (Appendix I). Table 2: Giving the description of the first and final water samples for all six days at both sites. Los Pinos (LP) and The Monteverde Institute (MVI) Day LP initia l grease size (mm) LP final grease size (mm) Clearer, merkier, the same Other objects present MVI initial grease size (mm) MVI final grease size (mm) Clearer, merkier, the same Other objects present 1 1 1 S a me N o 1 1 Clearer no 2 1 1 Merkier No 1 0.5 Clearer no 3 1 1 Merkier No 1 1 Merkier No 4 1 1 Same No 1 1 Clearer No 5 1 1 Clearer no 1 0.5 Clearer Yes 6 1 1 Clearer No 1 1 Cl earer No DISCUSSION Los Pinos Hotel (LPH) and the Monteverde Institute (MVI) both have a filtering system that includes preliminary treatment and primary treatment. Preliminary treatment include s some type of filter that focuses on removing large solids such as food scraps, plastic, d ryer lint, etc. Primary treatment aims to reduce residue with grease traps, flo tation t ank s , biogardens, etc.
Assessment of greywater parameters throughout treatment sites Arriaga 12 ! ! ( Arias Zuniga, 2010 ) I tested six parameters to determine if the greywater was changing when i t entered the system, while it was in the system, and at the end of the system. The temperature at LPH the temperature was not significantly different ; while, the temperature at MVI was significantly higher at the end of the treatmen t. C hanges in water temp erature can be affected by air temperature, rain water, turbidity, and sunlight (Behar, 1997). Since all sections of the system at LPH were in some way exposed to the surrounding environment, the ambient temperature directly interacted with each section , resulting in similar temperature condition s . At the MVI, the change in temperature did not occur until the second half of the system. The first half of the system only treats kitchen water, but in the second half, greywater from bathroom sinks and shower s enter the system. The mixture of different greywaters a ffects the parameters from the original half , in this case temperature . Also, hot water rises while cold water cools and the last section had the least amount of water compared to the other five sect ions (Behar, 1997); therefore, the lack of more water cause d temperature balance to change. Although the system has another half of biogarden that I did not test, it is likely that the temperature would stay the same since the conditions are similar or would rise because there would be even less water in the system. However, all points for both sites were between 19 and 23 degrees Celsius. According to Costa Rican wate r laws, treated grey water should have a temperature between 15 and 40 degrees Celsi us, meaning that both system comply with these standards ( El manej o de las aguas grises , 2014 ). Water temperature majorly influences biological activity and growth. The temperature of a system can determine what kind or organism can grow there (Behar, 1997 ). In their article, Water Temperature, The F o ndriest Environmental Incorporation (2016) discusses how t emperature alone can affect the metabolic rate of aquatic organisms and a 10!C increase in water temperature will approximately double the rate of physiological function . Tropical aquatic plants are also sensitive to temperature and most require warmer temperatures to flourish ( >21 !C) (Fundamentals of Environmental Measurements, 2016). Even more importantly, temperature directly affects othe r parameters of water that together can have a larger impact on a system. Warm water holds less dissolved oxygen (DO) which e ffect s the survival of different aquatic organism (Water Properties: Temperature , 2016 ). Although LPH did not have an increase in temperature, it still had an average temperature above 20 !C, as did the MVI. This constant "warm" water resulted in significant decrease in DO levels. A healthy ecosystem requires high levels of dissolved oxygen for organi sms to survive Ã‘ 0 2 mg/L: not enough oxygen to support life; 2 4 mg/L: only a few fish and aquatic insects can survive; 4 7 mg/L: good for many aquatic animals, low for cold water fish;7 11 mg/L: very good for most stream fish (Behar, 1997). However, a few factors can contribute to a decrease in DO. A dding chemical s, r aising the temperature of water , or having a high activity of microbial organisms (e.g. bacteria or algae) can impact the DO in water ( Spietz et al, 2015 ) . The DO at MVI (p<0.0001) started at 6.08mg/L and ended at 0.26 mg/L. LPH (p<0.001) started at 7.79mg/L and ended at 0.78 mg/L. Therefore, the end water for both sites does not have enough oxygen to support life. To my knowledg e, there is no Costa Rican water law value for DO levels. Althoug h I did not test for bacterial growth, according to Spietz, decreasing levels in DO are usually d ue to bacterial growth (2016). However, like other organisms, when DO in wate r depletes, bacteria begin to die. Both sites introduce the ir greywater from the end of their systems back into th e grassy area around their biogarden. With such low oxygen levels, the bacteria would not affect the grass where the final greywater is being deposited.
Assessment of greywater parameters throughout treatment sites Arriaga 13 ! ! Dissolved oxygen is also directly correlated to salinity levels, the lower the dissolved oxygen concentration, the higher the salinity levels. Salinity is the total concentration of all dissolved salts in water (Conductivity, Salinity, & Total Dissolved Solids , 2016 ) . This pattern was more evident at LPH with a significant increase in salinity levels, and less at the MVI where no significant change was determined. To my knowledge, there is no Costa Rican water law value for salinity levels. Drinking water and healthy rivers both have salinity levels of zero. Disposing of water with high salinity levels can cause problems in soil and in water sources. Too much salt in soil can af fect the water uptake of roots, al so make the soil prone to erosion , and can result in salt staying in one area for some time (Rolston et al, 1964). Since both are introducing the water back into their lawns, over time, a high concentration of salt on the surface can cause native p l ants to di e and pollute water sources . S imilarly, to temperature, organisms can only survive in certain salt concentrations . However, because neither location is introducing the greywater directly into a river, this is not an immediate problem. But, if no action is taken, erosion can lead to the salt bei ng dispersed, especially during rainy season , and eventually ending up in waterways. Vary ing salt concentrations in water directly affect the conductivity in the water, the higher the salinity the higher the conductivity. Conductivity is the level of conc entration of ions that affects water's capability to pass an electrical current. High quality deionized water has a conductivity of about 55 ÂµS/cm at 25 Â¡C, drinking water ranges between 50 Ã 500 ÂµS/cm, and sea water is 50000 ÂµS/cm (i.e., sea water's conductivity is one million times higher than that of deionized water) ( Conductivity, Salinity & Total Dissolved). The data supports this with LPH having a significant increase in conductivity , while the MVI did not significantly change; which are directly correlated to the results of salinity. The final median for the MVI was 196.000 Âµ S/cm and for LPH was 210.00 Âµ S/cm. These results show that they are both within the salt range of drinking water; however, because the final temperatures for the MVI and the LPH were below 25C then the results could still change. To my knowledge, there is no Costa Rican water law value for conductivity lev els. However , the conductivity for laundry is much higher than for kitchen and bath grey water ( Arias ZÂœ"iga, 2010 ) , so it is expected for LPH to have a higher conductivity than MVI . Laundry water has a higher conductivity because detergents have a high concentration of ions (Nganga et al, 2012), which decreases viscosity Ã‘ a liquids ability to resist flow . Viscosity is a lso directly affected by temperature, an increase in temperature is an increase in conductivity (decrease in viscosity) because ionic mobility is dependent on viscosity ( Fundamentals of Environmental Measurements, 2016). Levels of conductivity affect soil composition similarly to salt concentrations. Salt concentration does not only correlate with conductivity, but also with t otal dissolved solids (TDS) . TDS are the combination of all ion particles smaller than 2 microns (0.0002 cm) including those that make up salinity concentration. This includes all the disassociated electrolytes that make up salinity concentrations ( Fundamentals of Environmental Measurements, 2016) . In "clean" water, TDS is approximately equal to salinity. In wastewater or polluted ar eas, TDS can include organic solutes (such as hydrocarbons and urea) in addition to the salt ions ( Bakare et al , 2017). This again is directly seen with LPH having a significant increase in TDS and the MVI not having a significant increase. Total dissolve solids are about 0.5 mg/L for laundry and 3.5 for kitchen. Like conductivity, this drastic change is due to the chemicals found in detergents. However, by Costa Rican water laws, grey water should have less than 0.05 mg/L of TDS when released. This strict number is important because the mixture of ion particles that can contribute to the concentration of TDS can include nitrates, phosphates, and
Assessment of greywater parameters throughout treatment sites Arriaga 14 ! ! hydrocarbons. All three of these ionic particles can cause an increase of bacterial and algae growth, which is h armful to humans and aquatic organisms (Minnesota Pollution Control Agency, 2008). All the above characteristics of water directly affect the pH of a system. However, LPH did not have a significant change in pH with a final pH of 6.79; while the MVI did h ave a significant decrease in pH creating a more acidic final water of 5. 31 . T his is expected because soaps and detergents often are alkaline and have a PH between 7 8 (Nganga et al, 2012). So , it makes sense the LPH is more basic than the MVI. The appropriate range by law to be between is 6.5 8.4 which the institute does not meet, but LPH does (Morel and Diener 2006). This could be due to the higher acidity in foods that are disposed of in the kitchen sink, such as coffee and tea (2014, Acid/ Alkaline Food Chart). Just like every other parameter, pH directly affects and is affected by every parameter. Th ese results show that there is a difference in treating the water. For future studies, testi ng other characteristics, such as phosphates and nitrates in the water could give a better picture of how the grey water is being treated. Also, potentially testing the are a s where the treated grey water is released and comparing it to areas that are not e xposed to the water and observing if a difference can be detected. Overall, being conscious about grey water and the importance of treating it before reusing or releasing is a step in the right direction. Los Pinos Hotel and the Monteverde Institute both a re doing a great service to their surrounding environment by taking the initiative in grey water treatment. I recommend Los Pinos Hotel to try to use biodegradable soaps to increase the effectiveness of their system. I would recommend the Monteverde Instit ute to try to balance the water that passes through their system to ensure an effective outcome. Acknowledgements I wo u ld like to thank my primary advisor, SofÂ’a, for her patience, encouragement, and support throughout the project. I would also like to thank Jorge and Lorenzo who work at the Monteverde Institute and helped me get myself on track by encouraging my ideas and giving me their expertise opinions. Also, the staff at Los Pinos Hotel, for allowing me to sample their system and always offering their help. Thank you to Luisa for helping me with all the lab equipment. And Syd for keeping me company all those late work days. Thank you, Franko for always remind me to stay tranquila. Thank you to Costa Rica, my family, and my school for giving me this opportunity. Pura Vida Literature Cited Arias ZÂœ " iga, A.L., ( 2010 ) SituaciÂ—n de PotabilizaciÂ—n y Saneamiento en Costa Rica. Decimosexto Informe Estado de la NaciÂ—n en Desarrollo Humano Sostenible. Retrieved from https://estadonacion.or.cr/files/biblioteca_virtual/016/ana_arias.pd f Bakare, B.F., Mtsweni, S., and Rathilal, S. (2017) Characteristics of greywater from different sources within households in a community in Durban, South Africa. Journal of Water Reuse and Desalination. Retrieved from http://jwrd.iwaponline.com/content/ppiwajwrd/7/4/520.full.pdf Bates, S. E. (2014). The Journey to Developing Interpretive Materials for the Monteverde Institute. Behar, S., (1997) Definition of Water Quality Parameters. Water Quality Committee.
Assessment of greywater parameters throughout treatment sites Arriaga 15 ! ! Retrieved from http://fosc.org/WQData/WQParameters.htm ! BosquEterno (2018). Watershed Property. Retrieved from https://bosqueternosa.wordpress.com/the watershed property/ Coler , E. (2015). Comparison of grey water tests before and after treatment in various locations around Monteverde. EAP Spring 2015. Retrieved from UCEAP Monteverde Station ! Conductivity, Salinity, & Total Dissolved Solids. (2016) Fundamentals of Environmental Measurements. Retrieved from https://www.fondriest.com/environmental measurements/parameters/water quality/conductivity salinity tds/#cond11a https://water.usgs.gov/edu/temperature.html ! El manjeo de las aguas grises en la Zona de Monteverde: Percepciones, Retos, y Soluciones (2014). GlobalizaciÂ—n y Salud Comunitaria. Retrieved from El Monteverde Institute. Fundamentals of Environmental Measurements (2016). W ater Temperature. Fondriest Environmental Inc. Retrieved from https://www.fondriest.com/enviro n mental measurements/parameters/water quality/water temperature/#watertemp2 Jackson, J. (2017) Building Costa Rica: Understanding Tico Plumbing. Howler Magazine Jefferson, B. , Palmer A., Jeffrey P., Stuetz R., and Judd S. (2004). Grey water characterization and its impact on the selection and operation of technologies for urban reuse . School of Water Sciences, Cranfield University, UK. Jordan, R., ( 2015 ). Water for the environm ent and for people. Stanford News. Retrieved from https://news.stanford.edu/features/2015/water/research/environment.html Minnesota Pollution Control Agency (2008). Nutr ients: Phosphorus. Nitrogen Sources, Impact ! on Water Quality A General Overview. Retrieved from https://www.pca.state.mn.us/sites/default/files/wq iw3 22.pdf ! Morel, A. and Diener, S. (2006). Greywater Management in Low and Middle Income Countries . ! Rep. no. 14/06. Dubendorf, Switzerland. ! Nganga, V. G. ., Kariuki, F. W., an d Kotut, K. (2012). A Comparison of the Physico Chemical ! and Bacteriological Quality of Greywater from Water Deficient Households in Homabay ! Town and Githurai Estates in Kenya. Th e Open Environmental Engineering Journal. Retrieved from https://pdfs.semanticscholar.org/ec1d/678bc93f20c72ea56d432535e0d50d0270ce.pdf ! Newell, S., Craig, D., and Harlow, S. (2005). ReedBed Maintenance Manual. The Monteverde Institute. Retrieved from http://www.collectivesessions.com/client/cor/public/ uploads/140483635475637e7f4c.pdf?1404836392 Rolston, D. E., Biggar, J.W., and Nielson, D.R. (1984). Effect of salt on soils. California Agriculture. Retrieved from http://calag.ucanr.edu/archive/?type=pdf&article=ca.v038n10p11 Sklivaniotis, M. and Angelakis, A.N. (2006). Water for Human Consumption through History. 1 st International Symposium on Water and Wastewater Technologies in Ancient Civilizations. Retrieved from http://www.a angelakis.gr/files/3%20FR88.pdf Walker, T., and Stanford, B. (2017). Direct Po table Reuse: Widespread Implementation Requires Ready Operators. Water Source. Retrieved from http://dx.doi.org/10.5991/OPF.2017.43.0009 ! Water Education Foundation (2018). Wastewater Treatment Proce ss in California. Retrieved from http://www.watereducation.org/aquapedia/wastewater treatment process california Water Properties: Temperature (2016). USGS. Retrieved from https://www.phmiracleliving.com/t food chart.aspx
Assessment of greywater parameters throughout treatment sites Arriaga 16 ! ! Appendix : Appendix A : An example of a biogarden outline. A pretreatment system usually is placed before the water enters the biogarden. The pretreatment system , the plants used, and size can vary. Appendix B: The first part of the grey water system at Los Pinos Hotel: 1) a mesh filter that catches solids in the water; (2) a stagnant area of water where the soap floats to the top and the rest continue below; ( 3) a pipe that delivers the water below into a serpentine tank; (4) a set of four switchbacks that allow the water to separate from the soap at a slower and more thorough rate .
Assessment of greywater parameters throughout treatment sites Arriaga 17 ! ! Appendix C: B iogarden, where water leaks out of two surface tubes allowing the water to seep down through various layers of sediment and roots that further filter the water . Holding tank where the water remains stagnant as it slowly drains into the garden at Los Pinos . Appendix D: The first part of the grey water system at the Monteverde Institute : (1) a mesh filter that collects solids, (2) a second trench that allows for separation of fats and oils; (3) a third trench that gives the water more time for separation. One of the two large tanks where the kitchen water mixes with the bathroom grey water and undergo sedimentation filtration.
Assessment of greywater parameters throughout treatment sites Arriaga 18 ! ! Appendix E: The first half of the biogarden, where I tested. Number 5 is the beginning and number 6 is the ending. A close up of the pipes of the biogarden where the water was tested. Appendix F: The YSI 556 Multi Probe System , a device used to calculate various parameters in a liquid solution.
Assessment of greywater parameters throughout treatment sites Arriaga 19 ! ! ! Appendix G: An example of the measuring strip used to determine the width of the grease or soap band. ! ! ! Appendix H: Samples from day number two and six at Los Pinos Hotel. ! ! ! Appendix I: Samples from day number two and six at the Monteverde Institute. ! !