various methods have been devised and used to create balance and harmony between human activity and the environment ( 15 ) .
the purpose of using these methods is modification and minimization of the negative effects and consequences of human activities by using a set of protective and reform measures ( 6 , 7 ) .
an environmental impact assessment ( eia ) is one of the best ways to assess the impacts of sections or activities of a project on the components of the environment by identifying and understanding the importance of the environment ; finally , according to the its results , it provides solutions to create greater consistency ( 8 , 9 ) .
this action is a decision - making process in order to reduce the impact of human activities on the environment through changes in how the project is done or if it needs to prevent its construction ( 10 ) . among the assessment procedures followed in iran ,
this method presented by leopold in the late 1960s in the global arena is a technic that considers all the environmental consequences of a project and is approved by the american national environmental law ; this method was used in this study ( 11 , 12 ) .
many environmental problems are caused by increased production of municipal solid waste , which causes pollution of soil , surface , and groundwater and the air .
traditional views regarding the release and open dumping cause and exacerbate many problems and environmental effects ( 13 , 15 ) . proper control and waste management play important roles in improving the quality of the environment and thereby promote public health and wildlife protection ( 16 , 17 ) .
for this reason , according to paragraph a of article 192 of the fifth development plan of the islamic republic of iran , landfills are projects for which an environmental impact assessment must be conducted . in recent years
, many studies in iran have been conducted to evaluate the environmental impact of projects ; for example , elahabadi et al .
conducted a descriptive study on a compost plant in sabzevar using the leopold matrix in 2010 . according to the results and comparing
the positive and negative effects , the plant s design and its implementation in the intended site were possible and have a positive rating ( 18 ) .
another study was conducted in the same way : proposed landfill options for special waste were evaluated in khorasan razavi . in that study
, eight suggested sites were prioritized in the first phase of site selection studies in terms of environmental conditions ; ultimately , three options were reported as the best options for construction of landfill ( 19 ) .
municipal solid wastes of gonabad have been disposed in traditional and improper methods in the current landfill at 15 kilometers north of the city for many years .
the population of gonabad was 36,367 people in 2011 , and the daily production of waste , on average , is 45 tons . any initial processing is not performed on waste .
waste is dumped into pits ( depth of 3 meters ) dug by machinery ( tranche method ) .
the lack of a proper drainage system to collect leachate and landfill gas is one of the current problems , thereby releasing offensive odors around the landfill and increased risk of explosion .
there is no lining in the base of landfill , so leachate can easily infiltrate and pollute the soil .
also there is no suitable site for hazardous and hospital wastes that are collected separately . because of improper enclosure of the disposal site
, low weight wastes such as paper and plastic easily flow out of place with the wind .
this problem can be intensified according to information received from the wind rose in the spring and summer , with southeast winds and southwest winds in autumn and winter .
part of the collection path is a dirt road , and movement of heavy waste collection vehicles causes the release of particulate matter into the air and reduces the air quality of the landfill .
total noncompliance with environmental standards and regulations , lack of cooperation on source separation , the unsuitability of the landfill and disposal method in gonabad s landfill are concerns that have caused many problems , especially in environmental and human health . prior to this study
, no study has been done to assess the environmental impact of this landfill . due to the growing population in gonabad and especially in the increase of immigration from surrounding towns , increasing
the amount of waste generated in the city is inevitable , and , according to the current improper conditions in the landfill , there are threats to public health of citizens and ecologically , along with biological threats to flora and fauna populations .
the main objective of this paper was to assess the environmental impacts of the current municipal solid waste landfill of gonabab by using the iranian leopold matrix method ( iranian matrix ) and reporting its negative environmental consequences .
this cross - sectional study was carried out to assess the environmental impacts of gonabad s landfill in 2015 .
this city is located in a warm and dry region in the southern province of khorasan razavi .
landfill soil is impermeable black kaolin , and underground waters in this area are in the high depth of the soil . in this study , the city s
gonabad s landfill is located in the 15 km of gonabad - mashhad road , latitude 34 degrees 54 minutes and longitude 50 degrees 52 minutes .
the landfill area is intended for the 100 hectares ; it was built and operated in 2010 . the environmental impact assessment ( eia )
the most common methods of eia in the world are the matrix , tables , network , maps overlay , and gis modeling .
selection procedure for conducting eia depends on various parameters such as type of project , environmental conditions , costs , timing , and available field and library information . in this paper , we evaluated the environmental impacts of landfill in gonabad using the iranian matrix .
the matrix method , as a common method , with the overall judgment of average , has no particular separation of time and place in the evaluation .
however , being standard and scientific , the reliability of evaluation criteria can be achieved by this method .
this matrix contains 100 works on the horizontal axis ( columns ) and 88 environmental factors on the vertical axis ( rows ) , which formed a table or matrix with 8800 cells ; any cell is an intersection of an activity from the horizontal axis and a parameter from the vertical axis .
matrixes has been formed for four environments ( physical , biological , economic , and social ) on the horizontal axis and activities that happened in various stages of the project on the vertical axis . in this method ,
the matrixes have been scored for each of the proposed options ( current landfill , compost plant , recycling plant , incineration , sanitary landfill ) in constructional and operational phases separately ( 20 , 21 ) .
table 1 shows the range and impact of environmental effects on each of environmental parameters . after scoring the matrix , the results
were concluded in excel software , and the combination of positive and negative effects on both phases of activities and final conclusion took place .
the final result is achieved as follows : if any of the options of the final score is less than 3 , that option is rejected ; if the final score of options is more than 3 , that option is acceptable with corrective measures ( 22 , 23 ) .
on average , 40 tons of municipal solid waste is produced daily in gonabad . according to physical analysis , organic waste by 70% and plastic by 9% are the most common type of waste produced in gonabad .
s waste , including organic waste , plastic , paper , metal and glass , are reusable ( composting and recycling ) . environmental impact assessment waste management
options in gonabad were conducted for constructional and operational phases of waste management options by using the iranian leopold matrix . in the process of scoring , in both construction and operation phases , positive and negative effects of all activities on the environment components
the average of negative effects was a result of positive and negative effects of each option .
a comparison of the final results of the environmental assessment of five options in this study by the iranian leopold matrix , in order to prioritize and identify the optimal choice for waste management in gonabad , is presented in table 2 .
the results showed that , despite the current open dumping option having no construction phase , the most negative effect is related to this option with a score of 2.35 . comparing
the average negative environmental impacts of each option showed that a composting option has the least negative environmental impact . in total , in all options studied in the construction and operation phases , most negative effects on the physical , biological , socio - economic environments were related to noise pollution , air quality , land ecosystems , income and costs , and an increase in real estate prices , respectively ; in the case of cultural environment , most negative effects were related to landscapes and social acceptance . in current open dumping of waste , soil characteristics in the physical environment , vectors in biological environment and health indicators and important diseases in operational phase have the greatest negative effects .
in all , of the four proposed alternative options , social acceptance has less negative points than the current option .
this study aimed to assess the environmental effects of waste management options , including sanitary landfill , current open dumping and recycling , composting and incineration plant by using the iranian leopold matrix in the city gonabad . summing up the results of the iranian leopold matrix showed that the first option ( current open dumping ) , with a score of 2.35 , has more negative impacts than other options ; thus it was selected as the fifth priority for waste management in gonabad .
environmental impact assessment has been done only for the operational phase in this option because this option does not need sanitary landfill facilities and advanced equipment . according to the final score of this option ( 2.35 ) , running this option has severe negative effects on environmental components ( table 2 ) , and its implementation is rejected .
this is mainly because of the nonconformity with environmental regulations and nonstandard nature of this method on waste management .
negative effects on the physical components mainly due to the exposure of soil and groundwater to wastes and leachate ( 3 ) .
improper disposal of municipal solid waste can cause a large entrance of hazardous pollutants to the environment . in this option
, there are fewer negative effects on economic components because it has less investment and operation costs and requires simpler equipment than other options .
the second option ( sanitary landfill ) , with a final score of 1.59 , has weak negative consequences on the environment components .
the negative effects of the implementation of this option are mainly related to socio - economic components and costs of digging the trenches and use of multilayer coatings ( 15 ) . according to the final score of the option ( 1.59 ) ,
iranian leopold matrix results indicated that the third option ( compost plant ) with a final score of 1.57 , has the lowest negative effects in five studied options and was selected as the first priority in waste management in gonabad . according to table 2 ,
the negative impact of this option was the less than the other options ; however , this option also will have weak negative consequences on the environment components .
the highest negative rates are related to high costs of implementing this option in its construction phase ; but since about 70% of the city s waste composition consists of biodegradable organic maters , the proceeds from the sale of compost , the project will be justified economically .
other advantages of this option are creation of job opportunities and the return of consumable materials and reducing the use of resources . the fourth option ( recycling ) , with a final score of 1.68 , was designated as the third priority for waste management in gonabad . because only about 22% of the waste in gonabad are recyclable components , and , due to the need for sophisticated equipment to separate and recycling sites and construction costs , the desirability of implementing this option in gonabad has been less than composting and sanitary landfill options . the fifth option ( incineration ) because of deficiencies such as high initial investment and maintenance costs , air pollution , odor and smoke problems and need to dispose of residual ash from the combustion process , with a final score of 2.3 , was selected as the fourth priority among the five options . at present , unsanitary disposal of waste is being done in gonabad , which has high negative effects , and it is expected to continue this trend , which will cause irreversible effects on environmental components .
environmental assessment of five different options for waste management in gonabad demonstrated that a compost plant with a final score of 1.57 has the least negative impacts . in a similar study done in birjand , the results were similar to those in the present study , and composting options were the first priority in waste management ( 23 ) .
also , in another study in which the environmental impacts of solid waste landfill in shahrekord ( 3 ) were evaluated , consolidated compost - recycling option was introduced as the first priority of waste management .
the similarities and differences from recent studies and the present study were mainly because of the different composition of waste and weather conditions in studied areas .
the results of this study showed that the current option ( open dumping ) , due to severe environmental damage and health problems , has been rejected and will not be responsible for waste management over the years .
compost plant options with the lowest negative score ( 1.57 ) was the best option for waste management in gonabad .
 introductionan environmental impact assessment ( eia ) before embarking on any project is a useful tool to reduce the potential effects of each project , including landfill , if possible . 
 the main objective of this study was to assess the environmental impact of the current municipal solid waste disposal site of gonabad by using the iranian leopold matrix method.methodsthis cross - sectional study was conducted to assess the environmental impacts of a landfill site in gonabad in 2015 by an iranian matrix ( modified leopold matrix ) . 
 this study was conducted based on field visits of the landfill , and collected information from various sources and analyzing and comparing between five available options , including the continuation of the current disposal practices , construction of new sanitary landfills , recycling plans , composting , and incineration plants was examined . 
 the best option was proposed to replace the existing landfill.resultsthe current approach has a score of 2.35 , the construction of new sanitary landfill has a score of 1.59 , a score of 1.57 for the compost plant , and recycling and incineration plant , respectively , have scores of 1.68 and 2.3.conclusionresults showed that continuation of the current method of disposal , due to severe environmental damage and health problems , is rejected . 
 a compost plant with the lowest negative score is the best option for the waste disposal site of gonabad city and has priority over the other four options . 
1. Introduction
2. Material and Methods
3. Results
4. Discussion
5. Conclusions