Why Is Nonpoint Source Pollution Difficult To Control?

Ecological Modelling and Engineering of Lakes and Wetlands

Yi Zheng , ... Zhongrong Lin , in Developments in Environmental Modelling, 2014

Abstract

Nonpoint source (NPS) pollution has become a major threaten to the aquatic environment throughout the world and remains a great claiming for ecology management. Process-based, spatially distributed, and dynamic models provide desirable resolutions to the management of NPS pollution. However, their reliability in solving real management problems has been seriously questioned, since the model simulation usually involves pregnant uncertainty with complicated origins. This chapter addresses origins, complication, and quantification approaches of the uncertainty, besides as its touch on on management decisions. A framework for addressing the dubiousness in modeling watershed NPS pollution was commencement presented. Within this framework, different sources of the uncertainty were discussed and strategies to quantify the doubtfulness sources were reviewed. Recent advances in uncertainty analysis (UA) techniques for complex watershed water quality models were then introduced. Information technology has been recognized that UA alone does non guarantee the reduction of incertitude, and improving data and model structure would be the ultimate solution. The next generation of watershed NPS pollution models must incorporate recent and futurity advances in understanding the pollution process, and reduce the model construction doubtfulness by better representing the process in the models. Hereafter research directions for addressing the uncertainty issue were discussed as well.

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Nonpoint Source Water Pollution

In Environmental Applied science (Quaternary Edition), 2003

Determination

Controlling nonpoint source pollution in our waterways is currently one of the biggest challenges facing engineers, regulators, and scientists. Many nonpoint pollutants originate from mutual, everyday human being activities, similar driving a auto, putting in a new rose bed, walking the dog, or edifice a house. Because of its widespread nature, nonpoint source pollution is difficult to contain, fifty-fifty harder to eliminate, and costly to mitigate. Source control through public education, community planning, and regulatory guidelines tin can exist very effective, merely oftentimes requires substantial changes in human behavior. Technological approaches, such as storm water BMPs, tin can help reduce nonpoint source pollution, but rarely if always eliminate it entirely. Add to this, it is hard to predict whether a pollution reduction effort will exist successful because of the big variability in performances seen in the existing storm h2o treatment systems. Given the rapid changes occurring in nonpoint source pollution treatment engineering science, it is important to continue gathering information on what works, what does not work, and what factors contribute to successful nonpoint source pollution reduction.

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ENVIRONMENT

J.S. Shortle , J.B. Braden , in Encyclopedia of Energy, Natural Resources, and Ecology Economic science, 2013

Abstract

Nonpoint source pollution poses distinctive challenges to theoretical analysis equally well as applied policy formulation and implementation These challenges stem in part from a defining feature of nonpoint pollution – the inability to meter nonpoint emissions from individual nonpoint polluters routinely at a reasonable cost. They are besides the effect of the inherent stochasticity of nonpoint pollution and the complex, heterogeneous, nonlinear relationships that exist between human activities that cause nonpoint emissions and the ecology impacts of those emissions. Economists have proposed innovative instruments for nonpoint pollution that take good efficiency properties in theory, but which may be highly impractical in real-globe settings. Policy advances that are essential to manage nonpoint pollution efficiently are problem-specific computational investigations that integrate economic models with biophysical models of environmental processes to explore second all-time designs and mixtures that explicitly address not only incentive structures to induce efficient abatement simply too the information and administrative costs that emerge from the inherent spatial, temporal, and technological complexity of the problem.

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Hybrid Bioreactor Based on Periphyton

Yonghong Wu , in Periphyton, 2017

12.1 Introduction

Nonpoint source pollution refers to water pollution from diffuse sources ( Wilson et al., 1986). Nonpoint source water pollution negatively influences h2o bodies from sources such as polluted runoff from agronomical areas draining into a river, or windborne debris bravado out to sea. Nonpoint source pollution may derive from many different sources with no specific solution able to rectify the trouble, making it difficult to regulate. Nonpoint source water pollution is difficult to control considering information technology comes from the everyday activities of many unlike people, such every bit fertilizing a lawn, using a pesticide, or constructing a road or building (Zheng et al., 2014).

The input of nonpoint source pollution is becoming a master source of pollution events, such as blackness water agglomerates in rivers, eutrophication, and harmful algal blooms in downstream waters, in both adult and developing countries later the command of point source pollution (Wu et al., 2010b). The nigh important correspondent of nonpoint source wastewater is nutrient losses from farmland, grassland, forest, and route surfaces (Ongley et al., 2010). Nutrients mainly refers to inorganic matter from runoff, landfills, livestock operations, and crop lands. The 2 main nutrients of concern are phosphorus and nitrogen (Cha et al., 2016; Ouyang et al., 2014). Phosphorus is a chief ingredient in many fertilizers used for agriculture also every bit on residential and commercial properties, and may go a limiting food in freshwater systems and some estuaries (Cho et al., 2016; Hao et al., 2012; Turner et al., 2013). Phosphorus is nearly often transported to water bodies via soil erosion because many forms of phosphorus tend to be adsorbed on to soil particles (Ferreira et al., 2016; Tomer et al., 2016; Zimmer et al., 2016). Nitrogen is the other key ingredient in fertilizers, and it generally becomes a pollutant in saltwater or stagnant estuarine systems where nitrogen is a limiting nutrient (Hosseini et al., 2016; Tong et al., 2016; Xing et al., 2016). Like to phosphorus in freshwaters, backlog amounts of bioavailable nitrogen lead to eutrophication and algal blooms (Tekile et al., 2015; Wu et al., 2015).

Nitrogen and phosphorus are the major pollutants in nonpoint source wastewater and are the leading causes of degeneration in water quality and the deposition of ecosystem office (Wu et al., 2010a). Therefore, information technology is very of import that an integrated technology is developed to simultaneously remove nitrogen and phosphorus from nonpoint source wastewater to protect the water quality in downstream surface aquatic ecosystems.

To engagement, many ecological measures have been adult to reduce nonpoint source pollution (Wu et al., 2010a). They can be summarized into three classes: (1) ecological management based on the model of agricultural nonpoint source pollution at the watershed calibration (Wang et al., 2008) such every bit the all-time direction practices issued by the US Environmental Protection Bureau (USEPA), (2) integrated ecological restoration to ameliorate the self-purifying role of ecosystems, such as hierarchical eco-restoration (Wu et al., 2010a,b) and GIS-based ecological–economic modeling (Lant et al., 2005), and (3) the construction of ecology applied science such every bit vegetative strips between pollution sources and receiving h2o bodies (Duchemin and Hogue, 2009), riparian zones (Hefting et al., 2006), synthetic wetlands (Kay et al., 2007), and agricultural drainage ditches (Moore et al., 2010).

The application of the aforementioned measures helps to filter nonpoint source wastewater, promote sedimentation of the suspended particles and the pollutants leap to them, and recover ecological system function (Duchemin and Hogue, 2009; Wu et al., 2010a,b). These mitigation measures are suited to the current socioeconomic context in watershed (Duchemin and Hogue, 2009; Gunes, 2008), in which the adoption of uncomplicated and inexpensive agri-environmental practices is advocated with a view to protecting water quality and managing farm fertilizer use.

Nonpoint source wastewater originating in urban/suburban areas is caused by both natural factors (i.east., rainfall) and man activities (i.e., the lengthened wastewater discharges of industrial parks and irrigation) (Chen et al., 2008; Martínez et al., 2000). These human activities brand the composition of nonpoint source wastewater more than complex and heterogeneous. For example, some heavy metals might be introduced by industrial activities, which atomic number 82 to changes in the properties of nonpoint source wastewater. Moreover, the concentrations of some components of the nonpoint source wastewater might exist increased due to the combination of high loading diffuse wastewater from industrial production in the urban/suburban areas. In addition, the trouble of controlling nonpoint source wastewater in suburban/urban areas is complicated by the vast territory and the multiple types of state use (Duchemin and Hogue, 2009). Thus, it is necessary to explore new engineering or integrate current technologies to control and manage nonpoint source wastewater in urban/suburban areas.

The activated sludge process, such as the A²/O process, has been widely applied to treat high loading wastewater and tin can simultaneously remove organic matter, nutrients (e.g., nitrogen and phosphorus) and metals (eastward.thousand., chromium and arsenic) because it is highly efficient and environmentally friendly (Samaras et al., 2009; Ying et al., 2010). Photoautotrophic systems such equally wetlands and ecological ditches are often used to purify depression loading wastewater because information technology is inexpensive and environmentally benign. Still, the treatment of sludge in wetlands enhances the cost and limits its application in many developing or underdeveloped areas. The ecological ditches typically crave a large area of state for large-scale engineering, which conflicts with the local residents' need for cropland and industrial land employ (Wu et al., 2010a). Thus, it is practical to combine the advantages of these two technologies and overcome the shortages of both in treating "real-world" wastewater.

Therefore, we propose an integrated technology-hybrid bioreactor combined A²/O and ecological ditch to simultaneously remove high-loading nitrogen and phosphorus from heterogeneous nonpoint source wastewater and recover the microbial habitats. In the proposed biointegrated solution, we believe the most of import issue is to bring the aquatic ecosystem in the hybrid bioreactor to a self-modulating and self-sustaining land. To facilitate industrial-calibration application, three additional considerations should be taken into business relationship: (one) the hybrid bioreactor should be hands employed, inexpensive, and highly efficient; (2) the technology should be environmentally beneficial; and (3) the ecosystem should exist cocky-cycling and the microbial habitats should be recovered.

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Agroforestry

P.Thou.R. Nair , ... M. Rosa Mosquera-Losada , in Encyclopedia of Ecology, 2008

H2o Quality and Environmental Amelioration

Agricultural nonpoint source pollution is a significant crusade of stream and lake contamination in many regions of industrialized world. A major causative source of this pollution is nutrients such as phosphorus (P) and nitrogen (N) that are lost from soils of fertilized agronomical and forestry operations, especially in fibroid-textured, poorly drained soils where drainage water ultimately mixes with surface water. It has been estimated that beefiness cattle operations on improved pastures (184 000 ha), unimproved pastures (33 500 ha), and rangeland (47 000 ha) on ranches are a large contributor of P loads to Lake Okeechobee, Florida, one of the largest freshwater lakes in the USA. Contempo studies have shown that agroforestry practices such as silvopasture and riparian buffer could exist a means of addressing the problem of environmental touch of nonpoint source pollution. The deeper and more all-encompassing tree roots volition invariably be able to take up more nutrients from the soil compared to crops with shallower root systems – the so-called 'safety-internet' effect that has been affirmed in diverse agroforestry situations. Consequently, food-leaching rates from soils nether agroforestry systems where trees are a major component tin can be lower than those from treeless systems. Other studies documenting the effects of planted riparian forests on stream quality in temperate agronomical settings take also been reported, for example, in northwestern United states of america.

The water-quality enhancement resulting from the reduction of nutrient loading could be a substantial ecology benefit of agroforestry in heavily fertilized agricultural landscapes. With increasing realization of the adverse impacts of chemical agriculture and climate change on availability and quality of water in many parts of the globe, water is now a disquisitional issue in natural resource management. Time-tested integrated land-use practices such as agroforestry could exist appropriate approaches to addressing the problem. However, the science of this is nonexistent and needs to be explored and established.

The connectivity and buffering upshot offered by the presence of agroforestry systems on the landscape is another important environmental benefit of agroforestry that is little appreciated. It is mutual knowledge that the increasing presence of trees of similar or different species in an agricultural setting will take many positive biophysical influences (come across the sections, titled 'Soil productivity and protection' and 'Carbon storage'). As the copse historic period, these influences increase in magnitude; therefore, it is to be expected that when trees are introduced into degraded agricultural landscapes (intercropping) and stream banks (riparian buffer), there will be gradual changes at the system (mural) level. Long-term studies of this nature are rare, simply some convincing examples are available (run across the department titled 'Ecological engineering: agroforestry system pattern'). The fire-protection benefit offered past extensive tree-based systems such as the dehesa in the Mediterranean region ( Figure 4 ) is another benefit that has traditionally been enjoyed but never valued in economic terms.

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Pollution of Aquatic Ecosystems I

F.Thousand. Wilhelm , in Encyclopedia of Inland Waters, 2009

Nonpoint Source Pollution

The diffuse nature of NPS pollution, unlike PS pollution, makes it hard to place and thus eliminate it. By and large, reducing or eliminating NPS pollution requires a concerted sampling effort over large geographic areas to identify contributing sources (e.g., straight rainfall that is contaminated versus contamination after contact with soil). One time contaminant sources take been identified, their emptying requires further attempt targeting the identified pools. For example, agriculture, peculiarly the application of nitrogen-based fertilizers to grow corn in the US Midwest, has been identified as one of the major sources contributing to the large dead zone (surface area that lacks oxygen) in the Gulf of United mexican states. Backlog fertilizer not taken upwards by plants during the growing season enters waterways via run-off and is eventually delivered into the Mississippi River and ultimately the Gulf. Because primary product in marine environments tends to be express by nitrogen, its arrival stimulates primary production. Once algal cells die and sink, their decomposition decreases dissolved oxygen concentrations, leading to hypoxic and anoxic conditions. Identifying and implementing actions to control the application of fertilizer, which may limit subcontract income, on farms far removed from where pollution issues are manifested will exist hard. Generally, the restoration of aquatic ecosystems suffering NPS pollution requires a multipronged arroyo, including best direction practices, e.thousand., leaving or reestablishing native vegetation (buffer strips) almost h2o bodies; reducing pollution sources, e.thousand., acid rain producing emissions; and direct in-organization management, e.g., application of alum to immobilize phosphorus or removal of contaminated sediment. All these approaches are expensive and require considerable coordination at a watershed scale to ensure success. Remediation processes are also hampered past the long-altitude ship of pollutants, which may brand the problem international and crave nations to cooperate. Because developed countries take made considerable progress in harnessing PS pollution, NPS pollution is receiving attention and funding. However, in developing countries, NPS pollution volition not be dealt with for a meaning fourth dimension to come. Can we afford to wait as the population continues to aggrandize and nations become flush?

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Piggery Wastewater Treatment with Integrated Constructed Wetlands

Miklas Scholz , in Wetlands for Water Pollution Command (Second Edition), 2016

Abstract

Chapter 36 highlights that nonpoint source pollution such every bit landspreading of nitrogen-rich piggery wastewater poses a significant threat to surface waters. The aim was to examine the treatment of anaerobically digested piggery wastewater using four different mesoscale integrated constructed wetland (ICW) systems planted with Glyceria maxima (Reed Sweet-grass). Four replicates were used for each system to appraise differences due to nutrient loading, hydraulic loading, and effluent recycling. All systems were effective in removing total organic nitrogen, ammonia–nitrogen, nitrate–nitrogen, and molybdate reactive phosphorus. Nevertheless, ammonia–nitrogen removal was the greatest challenge for high menses rates (>100 1000ⁱⁱⁱ/ha/twenty-four hours). Nitrification was higher in summer than in winter. Readers will capeesh findings showing that effluent recycling within ICW was benign to lower ammonia–nitrogen only was associated with higher operational costs. The cost–benefit ratio based on ammonia–nitrogen removal for standard, recycling, high nutrient, and loftier flow rate treatments was 1.08:1:04:i.06:i.00. It follows that a high flow rate was only marginally more cost-effective.

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The Evolution of Analytical Technology and Its Impact on Water-Quality Studies for Selected Herbicides and Their Deposition Products in Water

Michael T. Meyer , Elisabeth A. Scribner(Retired) , in Handbook of H2o Purity and Quality, 2009

Mass Spectrometry

To assess the furnishings of agricultural nonpoint-source pollution in surface h2o and groundwater and the environmental fate and effects of emerging organic contaminants, it is of import that robust analytical methods be developed for these contaminants in soil and water. In the early 1950s, the fragmentation of small organic molecules was beginning to exist understood, but the mass spectrometer was very limited in sensitivity and resolution. This early instrument was the precursor of today'southward reasonably priced bench tiptop instruments seen in virtually chemical laboratories in the world (Mass Spectrometry Resource, 2005).

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Saltwater Toxicity Tests

B. Anderson , B. Phillips , in Marine Ecotoxicology, 2016

6.3.10.2 Stormwater Monitoring

Regulatory concerns in California accept recently emphasized nonpoint source pollution, and ambient testing in the marine environment has included monitoring of stormwater entering the nearshore littoral habitats, such as bays and estuaries. A number of contempo studies take documented stormwater toxicity using Pacific Coast species. Schiff et al. (2003) monitored toxicity of stormwater entering San Diego Bay, California, using the majestic sea urchin (South. purpuratus) fertilization examination. Laboratory testing of field-collected samples in conjunction with field mapping of the stormwater feather was used to bespeak the extent of toxicity in the bay. Chemical analyses and TIEs showed that toxicity was nearly likely due to zinc. In a like report using sea urchin fertilization tests, Bay et al. (1999) mapped the extent of ocean surface toxicity where Ballona Creek entered the ocean in southern California. These authors found that toxic plumes extending over iv km² were measured in Santa Monica Bay following large storm events. Chemical analyses and TIEs indicated toxicity to sea urchin sperm was again probable due to zinc. These authors conducted synoptic studies of benthic macroinvertebrate communities but did not detect impacts in the offshore environment.

Two studies accept used tests with fish embryos and larvae to document stormwater toxicity in California. As part of NPDES stormwater monitoring requirements, Skinner et al. (1998) conducted tests with embryos of inland silversides (Grand. beryllina) and medaka (O. latipes) to investigate effects of stormwater from a number of creeks in littoral San Diego County. In addition to egg mortality and larval hatching success, a number of teratogenic endpoints were evaluated. Developmental impacts and/or larval mortality were observed in 74% of the samples tested. Impacts on fish embryos were correlated with metals in these samples, peculiarly copper, atomic number 82, and zinc.

Phillips et al. (2004) tested samples from 15 stations entering Monterey Bay in key California as part of the Monterey Bay National Marine Sanctuary First Flush stormwater sampling program. Tests were conducted with larval topsmelt (A. affinis) and bivalves (M. galloprovincialis). Offset flush samples entering this system caused widespread toxicity to topsmelt, and TIEs and chemical analyses of stormwater suggested toxicity was due to high concentrations of copper and zinc. Bivalve (M. galloprovincialis) embryo evolution was also inhibited past the bulk of these stormwater samples and in those samples where TIEs were conducted, metals (copper and zinc) were implicated as the crusade of toxicity. Toxicity testing of stormwater is becoming a required component of NPDES monitoring in California. When combined with chemical analyses and TIEs, marine toxicity tests provide important information on potential hazards of stormwater discharge, and this information may be used to help identify contaminants of concern, a primal stride earlier source control.

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PHOSPHORUS IN SOILS | Overview

J.T. Sims , P.A. Vadas , in Encyclopedia of Soils in the Surround, 2005

Phosphorus Losses from Soils

Phosphorus transfer from soils to aquatic environments is a major nonpoint-source pollution business concern. The major pathway for P loss is surface runoff and soil erosion, although P can also be transported past subsurface h2o period to nearby streams, especially if artificial drainage is present (eastward.g., tiles, drainage ditches). As rainfall or irrigation water interacts with the surface soil, P desorbs or dissolves from soil particles, crop residues, fertilizers, or manure. Dissolved P can get out a field in surface runoff or be resorbed by soil or runoff sediment and then move as particulate P. The eroded sediment load in surface runoff determines particulate P loss. In areas where soils are vulnerable to wind erosion, soil P tin can also exist transported with fine, current of air-blown sediments and deposited in nearby waters. Years of extensive inquiry show that P loss is minimal when management practices forestall surface aggregating of P and minimize surface runoff and erosion.

Because soil P is relatively immobile, nearly fertilizer P remains nearly the soil surface. Nonetheless, leaching of P from the surface soil into the subsoil may occur in sandy soils and organic soils, and may be greater in soils where organic fertilizer is added than where inorganic fertilizer is added (Figure two). Leaching usually occurs in soils where P additions accept increased soil P to excessive concentrations. In such soils, P is more mobile because sorption sites have become increasingly saturated and solution P concentrations take increased. Leaching of P can exist exacerbated by preferential h2o flow where soil h2o containing relatively high concentrations of P from surface layers flows rapidly through soils in cracks, fissures, biopores, or finger flow. Phosphorus that has leached from surface soils may be retained in subsoils, gradually leach further into groundwaters, or move past subsurface flow to nearby streams.

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