Integrated Wastewater Management Reporting at Tourist Areas for Recycling Purposes, Including the Case Study of Hersonissos, Greece

Wastewater treatment facilities in tourist areas, in comparison to other municipal facilities, require specific configurations and additional management actions in order to achieve a reliable and cost-effective treatment. For example, the same facility operates during winter with minimum flows and in summer with peak flows. Moreover, careful effluent management is required to minimize environmental impact and health effects on tourists. In this study, effluent management data, including quantitative and qualitative effluent characteristics, reuse, and economic aspects of the Hersonissos Wastewater Treatment Plant (WTP) in Greece, are discussed. It has been designed to treat both municipal wastewater from the Hersonissos Municipality and septage from the wider area. Analysis of effluent quantitative data showed two flow peaks in the summer period and only one in winter. The WTP was found to provide a reliable level of treatment in terms of biochemical oxygen demand (95.9%), total suspended solids (97.2%), and total nitrogen (87.7%) removal, but increased numbers of fecal coliforms were measured at some peak flow periods, suggesting the need for additional management strategies. Effluent is reused mainly for agricultural irrigation; secondary uses include fire protection and landscape irrigation. Economic analysis showed that for each cubic meter treated, the total annual economic cost for treatment, filtration, and reuse infrastructure was 1.07 €, 0.05 €, and 0.08 €, respectively.     

MODELING HYDROLOGIC IMPACT OF WITHDRAWING THE GREAT LAKES WATER FOR AGRICULTURAL IRRIGATION1

ABSTRACT: Growing interest in agricultural irrigation in the Great Lakes basin presents an increasing competition to other uses of Great Lakes water. This paper, through a case study of the Mud Creek Irrigation District in the Saginaw Bay basin, Michigan, evaluates the potential hydrologic effects of withdrawing water for agricultural irrigation to the Great Lakes. Crop growth simulation models for corn, soybeans, dry beans, and the FAO Penman method were used to estimate the difference in evapotranspiration rates between irrigated and nonirrigated identical crops, based on climate, soil, and management data. The simulated results indicate that an additional 70–120 mm of water would be evapotranspirated during the growing season from irrigated crop fields as compared to nonirrigated identical plantings. Dependent upon the magnitude of irrigation expansion, an equivalent of about 1 to 5 mm of water from Lakes Huron-Michigan could be lost to the atmosphere. If agricultural irrigation further expands in the entire Great Lakes basin, the aggregated potential of water loss to the atmosphere through ET from all five Great Lakes would be even greater.     

WATER REUSE FROM SEWAGE EFFLUENT BY IRRIGATION: A PERSPECTIVE FOR HAWAII1

ABSTRACT: Surrounded by an ocean, the Hawaiian Islands are limited in their natural fresh water resources. The major readily developable potable sources are the high quality ground water sources which serve both domestic uses and sugarcane irrigation although irrigation water does not require as high a quality as drinking water. The increasing overall fresh water requirements for the island of Oahu will outstrip the potential yield of fresh ground water sources, as developed by present technology, by the year 2000 according to Honolulu Board of Water Supply projections. There are water shortage regions on other islands. Water reuse from sewage effluent for irrigation will augment natural water resources, furnish supplemental or alternative fertilizer, and reduce ocean water pollution and the costs of engineering systems. In cooperative field testing from 1971 to 1975, it was demonstrated that effluent can be applied as supplemental water for furrow irrigation of sugarcane without detriment to ground water quality and sugar yield. Studies are in progress to test different dilutions of effluent and its use with chemical ripeners to improve crop yield. Sugarcane plantations on Oahu, Maui, and Kauai are in various stages of water reuse by effluent irrigation. Reuse is presently practiced for irrigation of golf courses and is being planned for forage crops in Hawaii.     

REUSE OF DOMESTIC WASTEWATER FOR IRRIGATION IN ARID ZONES: A CASE STUDY1

ABSTRACT: The domestic sewage of the city of Beer-Sheva, Israel, which is located in an arid region, is treated in a series of facultative ponds. The treated effluent is stored temporarily in an open surface earthen reservoir (about 0.5 ± 10⁶ m³ in volume) and then used for irrigation. The effluent is applied via sprinkler and trickle irrigation systems. The main crops irrigated are cotton, wheat, alfalfa, and corn. Total cotton yield is over 5500 kg/ha, and the wheat grain yield is over 7500 kg/ha. The amount of effluent applied is about 6500 m³/ha for cotton (including preplant irrigation), and the wheat receives about 4500 m³/ha via irrigation and an additional 2000 m³/ha from precipitation. Due to the nutrient content in the effluent, the above yields are obtained without any additional fertilization.     

Are Investments in Groundwater Irrigation Profitable? A Case of Rice Farms from South India1

Varghese, Shalet Korattukudy, Jeroen Buysse, Aymen Frija, Stijn Speelman, and Guido Van Huylenbroeck, 2012. Are Investments in Groundwater Irrigation Profitable? A Case of Rice Farms from South India. Journal of the American Water Resources Association (JAWRA) 1‐15. DOI: 10.1111/j.1752‐1688.2012.00690.x Abstract: This article examines the profitability of cultivating double rice under bore well irrigation, given the cumulative interference of and reduced life span of wells, and thus increases the cost of groundwater extraction and use. The overexploitation of groundwater is a common stock problem and the cultivation of water intensive crops, such as rice, further exacerbates the overdraft of groundwater. Under these circumstances, we quantify the marginal benefit of irrigation investments in rice farming by estimating the probability of having a double rice crop as a function of the investment made in wells. Using this information, we explore profit maximization behavior of farms with a mathematical programming model to derive individual economic optima of irrigation costs. The results demonstrate that the ongoing overexploitation of groundwater, and its use to cultivate an economically inefficient crop, such as rice, has resulted in low profitability at farm level. A sensitivity analysis found that even when the investment in irrigation wells is reduced by 70%, small farms are still not economically efficient, thereby confirming the Tragedy of the Commons. Raising awareness amongst farmers with regard to the economics of irrigation would facilitate the participatory implementation of control mechanisms to regulate groundwater extraction.     

Nitrous oxide and ammonia fluxes in a soybean field irrigated with swine effluent

In the United States, swine (Sus scrofa) operations produce more than 14 Tg of manure each year. About 30% of this manure is stored in anaerobic lagoons before application to land. While land application of manure supplies nutrients for crop production, it may lead to gaseous emissions of ammonia (NH3) and nitrous oxide (N2O). Our objectives were to quantify gaseous fluxes of NH3 and N2O from effluent applications under field conditions. Three applications of swine effluent were applied to soybean [Glycine max (L.) Merr. 'Brim'] and gaseous fluxes were determined from gas concentration profiles and the flux-gradient gas transport technique. About 12% of ammonium (NH4-N) in the effluent was lost through drift or secondary volatilization of NH3 during irrigation. An additional 23% was volatilized within 48 h of application. Under conditions of low windspeed and with the wind blowing from the lagoon to the field, atmospheric concentrations of NH3 increased and the crop absorbed NH3 at the rate of 1.2 kg NH3 ha(-1) d(-1), which was 22 to 33% of the NH3 emitted from the lagoon during these periods. Nitrous oxide emissions were low before effluent applications (0.016 g N2O-N ha(-1) d(-1)) and increased to 25 to 38 g N2O-N ha(-1) d(-1) after irrigation. Total N2O emissions during the measurement period were 4.1 kg N2O-N ha(-1), which was about 1.5% of total N applied. The large losses of NH3 and N2O illustrate the difficulty of basing effluent irrigation schedules on N concentrations and that NH3 emissions can significantly contribute to N enrichment of the environment.     

Securing water for wetland conservation: a comparative analysis of policy options to protect a national nature reserve in China

This study evaluates four policy options to secure the water supply needed for wetland conservation in Qixinghe--a national wetland nature reserve in China--using four criteria: cost effectiveness, probability of success in achieving the water-saving goal, political feasibility, and farmer acceptance. This multi-criteria analysis framework reveals the ecological, economic, and socio-political trade-offs for policymakers when choosing among the four policy options. Results suggest that upgrading irrigation infrastructure in the area surrounding the wetland (Option I) is the most politically feasible option, but it is the second best option in terms of cost effectiveness. Constructing a dam to store and control floodwater (Option II) is the most reliable for achieving the water-saving goal. It is also the farmers' most favored strategy. But this option is the least cost effective and receives little support from local governments. Promoting farmers' adoption of water-saving practices (Option III) is the most cost effective, but it is less reliable for achieving the water-saving goal than Options I or II. Converting paddy crops to dry-land crops (Option IV) is politically infeasible and least reliable for achieving the water-saving goal. The overall ranking of the four options is determined using the policymakers' revealed weights on the four criteria. Option I is ranked first, followed by Options II, III, and IV.     

OPTIMIZATION OF WATER RESOURCES FOR IRRIGATION IN EAST JORDAN1

The paper describes an approach towards optimal allocation of surface and ground water resources to three agricultural areas in the Jordan Valley under conditions of scarce water supply. The optimizing model allocates water from three main rivers, each with reservoir storage, and from two ground water sources to three irrigation regions. Productivity of irrigation water, expressed as the net present value of the regional agricultural output, but allowing for crop water deficits, is first maximized using nonlinear programming. The allocation process then adopts techniques of linear programming to determine the least cost alternative based on the unit cost of water from each resource at each destination, as it varies with time.     

VALUING IRRIGATION WATER IN PUNJAB PROVINCE,PAKISTAN: A LINEAR PROGRAMMING APPROACH1

ABSTRACT: Linear programming models of a representative farm in a district of Pakistan's Punjab Province are formulated for the purpose of estimating the value of irrigation water. The models provide for choices among several irrigation levels for each potential crop. Solutions of the model for several water supply situations provide the basis for approximating the total, average, and marginal values of irrigation water. Prices for important crops in Pakistan are controlled at levels below their levels elsewhere in the world, so models are specified for both financial (domestic price) and economic (world price) scenarios. The value of water to society (its economic value) is high relative to the costs of some generally available water-augmenting investments, while financial values, which measure water management and allocation incentives faced by farmers, are less than the corresponding economic values. At current water supply levels, incremental returns to added water estimated from the economic model would justify investments in water-saving or water-augmenting technologies, while such a decision would be barely attractive assuming financial prices. While present government commodity price policies may serve to protect low-income and non-farm members of the population, they also inhibit farmer investments to increase the productivity of scarce irrigation water.     

GROUNDWATER QUALITY IN THE CORTARO AREA NORTHWEST OF TUCSON,ARIZONA1

ABSTRACT The Cortaro Area is currently the depository for much of the liquid waste from the City of Tucson. In the past, more than one-half of the sewage effluent was used for crop irrigation. However, since 1970 virtually all of the sewage effluent has been percolated in the normally dry Santa Cruz River channel. Nitrate and chloride contents were monitored monthly in water samples from about 20 large-capacity irrigation wells. Contents and seasonal trends for these constituents were closely related to the disposal of sewage effluent. Water quality problems other than nitrate include total dissolved solids, boron, coliform, and lead. High lead contents in the area appear to be a natural phenomenon and the coliform contents are likely related to poor well construction. The other quality problems are primarily due to sewage effluent.     

Management of treated pulp and paper mill effluent to achieve zero discharge

Pulp and paper mills are one of the major effluent generating industries in the world. In most cases, mill effluent (treated or raw) is discharged back into a river, creek, stream or other water body; resulting in negative environmental impacts, as well as social concerns, among the downstream users. Pulp and paper mill effluent management, which could result in zero discharge into downstream water bodies, would present the best management option to address socio-environmental concerns. This paper presents such an effort aimed at closing the water cycle by using treated effluent from the mill to irrigate forage and fodder crops for producing animals feed. The treated effluent is delivered from the mill through gravity into a winter storage dam of 490ML capacity. For irrigation applications on 110ha of farmland, which is 42% of the total farmland, the water is pumped from the winter storage dam to five individual paddocks with Centre Pivot (CP) irrigators and one rectangular paddock with a Soft Hose Travelling (SHT) irrigator. From October 2001 to June 2006, a total of 2651mm of wastewater was applied at the farm. The impact assessment results, obtained from field monitoring, investigations and analysis, indicated that the closed water cycle effluent management strategy described had resulted in a lessening of the impact on water resources usually associated with paper mills. However, social attitudes to the use of crops that have been irrigated with recycled waters and the resulting impact on market value of the produce may still be a major consideration.     

METHODOLOGY AND EMPIRICAL ESTIMATES OF THE RESPONSE FUNCTION OF SORGHUM TO IRRIGATION AND SOIL MOISTURE1

ABSTRACT: This paper presents a methodology for the estimation of response functions of crops to irrigation and soil moisture. A system analysis framework is applied to describe the relationships involved. Two subsystems are distinguished, with the first one involving the relationship between irrigation decision variables and soil state variables, and the second involving the relationship between soil state variables and crop yield. A method for tracing and predicting soil moisture profile variations over time and depth is presented, and empirical estimates of the response function of grain sorghum to soil moisture are derived. In the specification of the response function the concept of “critical days” is applied with a “critical day” being defined as one where the soil moisture is depleted below a certain critical level. The paper provides empirical evidence for the usefulness of the approach     

ON THE NECESSARY AND SUFFICIENT CONDITIONS FOR A LONG-TERM IRRIGATED AGRICULTURE1

ABSTRACT. Salinization and water logging have been the nemesis of irrigated agriculture societies since Babylonian times. Low quality water substitutes for high quality water for irrigation at an increasing rate up to the limits of the soil's ability to transmit the additional water and remove excess salts from the root zone. Soil transmissibility can be increased by additional investment in drainage ditches and underground tile. Low valued-high salt tolerant crops can be substituted for higher valued-salt sensitive crops to maintain production in areas served by irrigation water sources of deteriorating quality. Thus physical factors specify the necessary conditions for survival of an irrigated agriculture. The sufficient conditions for survival must be in terms of a positive net income in each subplanning period discounted to its present value.     

Leaching of three imidazolinone herbicides during sprinkler irrigation

Some imidazolinone herbicides have been shown to be mobile in soil, raising concern about their possible movement to ground water. Three imidazolinone herbicides (imazamethabenz-methyl, 497 g ha(-1); imazethapyr, 14.7 g ha(-1); and imazamox, 14.7 g ha(-1)) commonly used in crop production on the Canadian prairies were applied to a tile-drained field to assess their susceptibility to leach when subjected to sprinkler irrigation using a center pivot. Tile-drain flow began when the water table rose above tile-drain depth, and peak flow rates corresponded to the greatest depths of ground water above the tile drains. Interception of irrigation water by the tile drains in each quadrant of the field varied from ～11 to 20% of the water applied. Under a worst-case scenario in which irrigation began the day after herbicide application and irrigation water was applied at 25 mm d(-1) for 12 d, there was evidence of preferential flow of all three herbicides and hydrolysis of imazamethabenz-methyl to imazamethabenz in the initial samples of tile-drain effluent. In subsequent samples, concentrations (analysis by LC-MS-MS) of the summation of imazamethabenz-methyl (25-24,000 ng L(-1)) plus its hydrolysis product imazamethabenz (63-26,500 ng L(-1)) greatly exceeded those of imazethapyr (<13-1260 ng L) and imazamox (19-599 ng L(-1)), thus reflecting relative application rates. In contrast, estimates of total transport of each herbicide from the root zone, which varied in each quadrant and ranged from 0.06 to 2.3% for imazamethabenz-methyl plus imazamethabenz, 0.71 to 3.1% for imazethapyr, and 0.61 to 2.8% for imazamox, did not reflect application rates. In shallow ground water (piezometer samples), there was inconsistent and infrequent detection all four compounds. With the frequency and amount of rainfall typically encountered in the prairie region of Canada, contamination of shallow ground water with detectable concentrations of the three imidazolinone herbicides would be unlikely.     

IMPROVING IRRIGATION RETURN FLOW QUALITY WITH A WATER RENTAL MARKET1

ABSTRACT: Current policies for correcting the problem of irrigation return flow pollution tend to attack the symptoms of the problem, rather than its cause. The present institutional arrangement for allocating irrigation water is seen as the source of the problem. This paper examines the water quality benefits of altering the institutional arrangement to allow for irrigation water transfers through a rental market. It is conceptualized that by creating a water rental market an opportunity cost would be associated with the use of irrigation water such that profit maximizing farmers would be induced to use his water supply more efficiently and rent the surplus to other irrigators, thus reducing return flow pollution. It is shown that a water rental market could increase water quality in the Yakima River in southcentral Washington by 31 percent as well as increase farm incomes and crop production.     

TECHNICAL AND INSTITUTIONAL ASPECTS OF SEWAGE EFFLUENT-IRRIGATION WATER EXCHANGE,TUCSON REGION1

ABSTRACT .Many growing municipalities near irrigated agriculture are advocating a transfer of water now utilized for irrigation to municipal use. Alternatives are presented whereby this water can be transferred to municipal use in exchange for treated sewage effluent. The irrigation water would in effect be cycled through the municipal system prior to use on the farms. A case study of the Tucson region illustrates the relevant legal, economic and technical aspects. Effluent could be delivered to irrigators in Avra Valley at a cost less than that now paid for water pumped from declining water tables. In return the City of Tucson could import ground water now being used for irrigation through an existing pipeline which presently cannot be used because of a court injunction obtained by the irrigators. It appears that such an exchange agreement could be made without modification of existing statutory law. Similar exchange arrangements may prove to be feasible in other regions containing irrigated agriculture. Increased efficiency of water use can be achieved avoiding external effects which commonly arise in a direct transfer and are difficult to evaluate. High quality water is allocated to municipal use whereas nutrient-rich sewage effluent is transferred to irrigation.     

Sorption-desorption of carbamazepine from irrigated soils

Th anti-seizure medication carbamazepine is often found in treated sewage effluent and environmental samples. Carbamazepine has been shown to be very persistent in sewage treatment, as well as ground water. Due to environmental persistence, irrigation with sewage effluent could result in carbamazepine contamination of surface and ground water. To determine the potential for leaching of carbamazepine, a series of adsorption and desorption batch equilibrium experiments were conducted on irrigated soils. It was found that carbamazepine adsorption to biosolid-amended (T) soils had a KD of 19.8 vs. 12.6 for unamended soil. Based on adsorption, carbamazepine leaching potential would be categorized as low. During desorption significant hysteresis was observed and KD increased for both soils. Desorption isotherms also indicate a potential for irreversibly bound carbamazepine in the T soil. Results indicate that initial removal of carbamazepine via adsorption from irrigation water is significant and that desorption characteristics would further limit the mobility of carbamazepine through the soil profile indicating that carbamazepine found in sewage effluent used for irrigation has a low leaching potential.     

Cadmium availability from granulated and bulk-blended phosphate-potassium fertilizers

Recent field experiments have shown that high chloride (Cl) in irrigation waters can increase soil cadmium (Cd) uptake by crops because of the formation of soluble ion-pair complexes of Cd with Cl in soil solution. The present study was aimed at testing a hypothesis that KCl in granulated PK fertilizers may enhance Cd uptake by crops from Cd-containing P fertilizers because of close contact between Cd and Cl in the same granules. Less effect would be expected if the same granular PK fertilizers were bulk-blended because of separation of Cd and Cl in different granules. A single superphosphate (SSP) containing 32 mg Cd kg(-1) was granulated by the compaction process with KCl at a P to K ratio = 1:1. Granular KCl was also bulk-blended with granular SSP or Cd-free monocalcium phosphate (MCP) at the same P to K ratio. An acid Ultisol (pH 5.2) was treated with PK fertilizers at 400 mg kg(-1) each for P and K. Upland rice (Oryza sativa L.) and soybean [Glycine max (L.) Merr.] were grown to maturity, and signalgrass (Brachiaria decumbens Stapf.) was cut four times during the study. The results showed that the agronomic effectiveness in increasing crop yield was the same with SSP and MCP whether granulated or bulk-blended with KCl. Concentrations of Cd in plant tissue samples of all crops were much lower for MCP than for SSP. In all the plant tissue samples, except grain samples of upland rice, Cd concentrations obtained with granulated (SSP + KCl) were significantly higher than that with bulk-blended (SSP) + (KCl).     

Assessment of Water Availability and Scarcity Based on Hydrologic Components in an Irrigated Agricultural Watershed Using SWAT

This study assesses the water availability and the water scarcity based on the hydrologic behavior under different weather conditions and crop coverages in an irrigated agricultural area of Rincon Valley in New Mexico using the SWAT (Soil and Water Assessment Tool) model. Two spatial crop coverages included normal (2008) and dry (2011) years with 14 different crop sets for each year. The SWAT was applied to generate the five essential indicators (surface flow, evapotranspiration, soil water, groundwater recharge, and irrigation water) to evaluate the integrated water availability based on hydrologic response units (HRUs) along with the Arrey Canal to supply irrigation water in the crop areas. The water availability index scores (0–1 range with 1 being the most available and 0 the least available) of alfalfa, corn, cotton, and pecans were 0.21, 0.56, 0.91, and 0.20, respectively, in the normal year and 0.16, 0.78, 0.88, and 0.24, respectively, in the dry year. In the dry year, water scarcity values were high in mostly alfalfa areas, whereas cotton areas have mostly no stress with good water availability. The major water users of crops, ranked in order, were alfalfa, pecans, cotton, and corn. During the dry year, water availability showed to be balanced in terms of water supply and demand by controlling crop patterns from reducing alfalfa acreage by 12% and increasing cotton acreage by 13%.