ENE802DESIGNPROJECT

MSUWaterReclamationSystem

PreparedFor:

Dr.SusanMasten

DepartmentofCivilandEnvironmentalEngineering

MichiganStateUniversity

SubmittedBy:

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TAP Engineering A119 Engineering Research Complex Michigan State University East Lansing, MI 48823

December 9th, 2008

Dr. Susan Masten Professor Department of Civil and Environmental Engineering Research Complex A130 Michigan State University East Lansing, MI 48824 Re: Final Report TAP Engineering has completed a design for a water reclamation system on Michigan State University’s campus. The reclaimed water will be used to irrigate Forest Akers Golf Course. Our proposed system meets all Federal and State regulatory requirements. We would like to thank you for our opportunity to serve the local community on this very unique and exciting project. Please, do not hesitate to contact us with any questions, comments, or concerns. Sincerely, TAP Engineering

Tan Zhao Adam Rogensues Prianca Bhaduri

Project Manager Project Manager Project Manager

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EXECUTIVE SUMMARY

Introduction The purpose of this project was to design and demonstrate an innovative water reclamation system for Michigan State University’s campus. It was decided, that in order to minimize any future conflicts involving MSU’s potable water supply, a wastewater reclamation system was designed to supply irrigation water for the Forest Akers Golf Course using treated East Lansing Wastewater Treatment Plant (ELWWTP) effluent.

Legal and Regulatory Issues There are currently no federal regulations governing water reclamation and reuse in the U.S.; the regulatory burden rests within the states. Michigan currently does not have any regulation or guidelines set forth for the use of reclaimed water for golf course irrigation, therefore TAP Engineering adopted the water quality and water quality monitoring suggested requirements set forth by the US Environmental Protection Agency. The estimated reclaimed effluent needed for this project is sufficiently low enough to inhibit the manifestation of riparian water right and water ownership conflicts. The ELWWTP effluent water quality has prohibitively high concentration of fecal coliform and a prohibitively low chloride residual concentration (according to the EPA guidelines), therefore, our treatment system was designed to reduce the fecal coliform concentration and increase the chloride residual.

Effluent Quality Considerations A few known potentially problematic effluent constituents include phosphorus, nitrogen, salts, and suspended solids. Nitrogen and phosphorus are vital plant nutrients, so removal of these constituents was not needed. Both chloride residual and coliform removal need to be increased in order to meet the EPA’s suggested water quality. The effects of elevated salt concentrations in the reclaimed water on irrigated soils is often evaluated using the SAR. Typically, SAR and the EC are looked at together in order to predict any potential salt related issues. Considering the close proximity of the ELWWTP effluent water quality to the quality needed for negligible use restrictions (see Table5), it was assumed that the ELWWTP effluent was close enough to the qualities needed to neglect any use restrictions. Furthermore, the implementation of membrane technologies is unwarranted and would most likely significantly increase the process cost

Comparison of Disinfection Technologies Both chlorine and UV radiation are used to treat wastewaters. UV radiation is a newer technology when compared to the established chlorination disinfection. We have chosen chlorine as a disinfectant over UV radiation due to the multiple problems associated with UV lamps such as fouling, scaling etc. and the higher capital cost of its installation. For our treated water uses, chlorine would effectively disinfect the water to within permissible levels. Chlorine disinfection is not as maintenance sensitive as other technologies and can function well once it has be properly calibrated. The various aspects of chlorine residual and by-product formation can be negated by making the necessary considerations and taking proper precautions in the treatment design.

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Theory of Chlorination Disinfection Chlorination is the process of disinfecting water by adding chlorine in the form of liquefied chlorine, sodium hypochlorite, or calcium hypochlorite. Chlorine reacts with water to form hypochlorous acid and hydrochloric acid which further dissociate to give hypochlorite, chloride and hydrogen ions. Formation of hydrogen ions causes a decrease in the pH and addition of alkali may be necessary to maintain the pH of water. Chlorine reacts with ammonia and amino nitrogen compounds dissolved in water to form chloramines. Usually enough chlorine is added to oxidize all the ammonia and amino nitrogen compounds present in the water; this ensures complete disinfection. The chlorine residual is monitored and kept within safety limits. Chlorine residual may be decreased by dechlorination processes such as adsorption onto activated carbon. Free chlorine also reacts with some organic and inorganic matter to form disinfection-byproducts (DBPs). Formation of DBPs can be minimized by adding excess ammonia so that all the chlorine in water is present in a combined form.

Disinfection Process Design A sodium hypochlorite chlorination system was designed to treat tertiary filtration effluent with a design flow of 0.3 MGD (1153.8 m3/d), which is part of the total available 13.3 MGD effluent. The objective was to reduce the fecal coliform concentration from an as received average of 430 fecal coliform/100ml, (peak of 60000 coliform/100ml) to “no detectable fecal coliform” which means the number of fecal coliform organisms should not exceed 14/100 ml in any sample. The desired minimum effluent chlorine residual was 1mg/L Cl2.

A programmable logic controller (PLC) was used to precisely control the chlorine dosage and residual using the signals from flow meter and residual analyzer. An injector pump type mixer was used to maximum contact. Since we have a stable effluent flow, a required residual of 1mg/L and the programmable logic controller, we do not have to include a dechlorination unit but we do have an ammonia system to convert free residual chlorine to combine residual chlorine to arrest the formation of disinfection byproduct.

Additional Design Processes Gypsum will added to the irrigation area on a monthly basis in order to compensate for elevated salt concentrations in the effluent water. Operational storage capacity will be managed by the expansion of the west pond located on the Forest Akers Golf Course grounds. The pumping facility(s) should be marked to indicate that it is a non-potable resource. Non-potable pipelines will be properly identified and have adequate protection to avoid cross contamination. Flush valves should be installed in every irrigation system, particularly in low spots and at dead-ends.

Public Perception It is our belief that via full project transparency and effective information relay are vital to gaining full public support and acceptance of our project. The following tasks will outline the core public relations strategy:

• Manage information for all.

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• Maintain individual motivation and demonstrate organizational commitment. • Promote communication in a public dialog.

• Ensure fair and sound decision making. • Build and maintain trust.

Costs

Standard Piping Costs Pipe Diameter

(inches) Cost ($/LF) Total LF Estimated

Capital Cost

10 100 8000 $ 800,000.00 Pipe Crossing Costs

Pipe Diameter (inches)

Cost ($/inch dia./LF) Total LF Estimated Cost

10 655 500 $ 327,500.00 Excavation Costs

Unit Cost (per yd3)

Estimated Excavation

Volume (yd3)

Estimated Capital Cost

$10.67 3000 $32,010.00 Estimated Gypsum Cost

Cost/Application Estimated Annual Applications Estimated Annual Cost

$3,000.00 5 $15,000.00 Estimated Chlorination Cost

Estimated Chlorination Capital Cost

Estimated UFC Cost

Estimated O&M Cost

Estimated Capital Cost

$132,000.00 $100,000.00 $30,000.00 $232,000.00 Estimated Sodium Hypochlorite Cost

Estimated Cost per m3

Estimated Annual Volume (m^3)

Estimated Annual

Cost Total

$140 41.975 $5,877.61 $5,877.61 SUMMARY

Distribution Systems

Total Capital Costs Annual Costs

$ 1,127,500.00 $ 1,391,510.00 $ 50,877.61

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TABLE OF CONTENTS

EXECUTIVESUMMARY .......................................................................................................................................... 2

Introduction........................................................................................................................................................... 2

LegalandRegulatoryIssues ........................................................................................................................... 2

EffluentQualityConsiderations .................................................................................................................... 2

ComparisonofDisinfectionTechnologies ................................................................................................ 2

TheoryofChlorinationDisinfection............................................................................................................ 3

DisinfectionProcessDesign............................................................................................................................ 3

AdditionalDesignProcesses........................................................................................................................... 3

PublicPerception ................................................................................................................................................ 3

Costs .......................................................................................................................................................................... 4

TABLEOFCONTENTS ............................................................................................................................................ 5

LISTOFFIGURES ...................................................................................................................................................... 8

LISTOFTABLES........................................................................................................................................................ 9

INTRODUCTION..................................................................................................................................................... 10

ProblemDefinition........................................................................................................................................... 10

Background......................................................................................................................................................... 10

RiparianRightsinMichigan......................................................................................................................... 13

WaterOwnership ............................................................................................................................................. 14

MonitoringRequirements ............................................................................................................................ 14

Summary .............................................................................................................................................................. 15

FederallyRegulatedContaminants........................................................................................................... 17

NitrogenandPhosphorus............................................................................................................................. 17

ChlorideandColiform .................................................................................................................................... 17

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SodiumAdsorptionRatio.............................................................................................................................. 17

Summary .............................................................................................................................................................. 20

COMPARISONOFDISINFECTIONTECHNOLOGIES................................................................................ 21

Advantagesanddisadvantagesofchlorine,chlorinedioxide,ozoneandUVradiation: ... 21

Chlorine............................................................................................................................................................ 21

ChlorineDioxide........................................................................................................................................... 22

Ozone ................................................................................................................................................................ 22

UVradiation ................................................................................................................................................... 23

Summary .............................................................................................................................................................. 24

THEORYOFCHLORINATIONDISINFECTION........................................................................................... 25

BasicChemistry................................................................................................................................................. 25

ModeofActionofChlorine........................................................................................................................... 28

FormsofChlorineApplication.................................................................................................................... 28

Summary .............................................................................................................................................................. 29

DISINFECTIONPROCESSDESIGN.................................................................................................................. 30

SizingChlorinationFacilities....................................................................................................................... 30

ChlorineContactBasinDesign.................................................................................................................... 31

DosageControl .................................................................................................................................................. 33

InitialMixing....................................................................................................................................................... 33

ChlorineResidual ............................................................................................................................................. 34

OthersConsiderations.................................................................................................................................... 35

Summary .............................................................................................................................................................. 35

ADDITIONALDESIGNPROCESSES ................................................................................................................ 38

CompensationforElevatedSaltConcentrations ................................................................................ 38

OperationalStorage......................................................................................................................................... 39

DeliverySystems .............................................................................................................................................. 39

PumpingSystems ............................................................................................................................................. 39

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Piping..................................................................................................................................................................... 40

Sprinklers............................................................................................................................................................. 40

FlushValves ........................................................................................................................................................ 40

PUBLICPERCEPTION .......................................................................................................................................... 41

ManageInformationforAll.......................................................................................................................... 42

MaintainIndividualmotivationanddemonstrateorganizationalcommitment .................. 42

PromoteCommunicationinaPublicDialogue.................................................................................... 42

SoundDecisionMaking.................................................................................................................................. 43

BuildandMaintainTrust .............................................................................................................................. 43

Summary .............................................................................................................................................................. 43

PrecipitationinchlorinecontactBasins................................................................................................. 45

WasteCharacterization ................................................................................................................................. 45

OperatingandHandlingHypochlorite .................................................................................................... 47

Containers............................................................................................................................................................ 47

Transportation .................................................................................................................................................. 47

FacilityDesign.................................................................................................................................................... 47

SITECONSIDERATIONS...................................................................................................................................... 48

CONSTRUCTIONPLANNING............................................................................................................................. 49

Chlorination ........................................................................................................................................................ 50

Piping..................................................................................................................................................................... 51

Excavation ........................................................................................................................................................... 51

Gypsum ................................................................................................................................................................. 51

Summary .............................................................................................................................................................. 52

APPENDIX................................................................................................................................................................. 56

WasteCharacterizationGuidelines .......................................................................................................... 56

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LIST OF FIGURES

Figure1.InjectorPumpTypeMixer[29].................................................................................................... 34

Figure2.Schematicflowdiagramforsodiumhypochloritechlorination.................................... 37

Figure3.AmountsofGypsumandSulfurrequiredtoreplaceindicatedamountsofexchangeablesodium .......................................................................................................................................... 38

Figure4.Planninginitiativeframeworkoutline[9]. ............................................................................. 41

Figure5.Publicopinionsurveyresultsonvarioususesofreclaimedwater[2]. ..................... 42

Figure6.Sitemapoftheprojectarea(aerialphotocourtesyofGoogleMaps). ........................ 48

Figure7.Estimatedcostsofchlorinationtreatmentfacilities[‐49‐] ........................................... 51

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LIST OF TABLES

Table1.EPAsuggestedwaterqualitystandardsforUrbanReusepurposes. ............................ 12

Table2.Ourrelevanteffluentquality........................................................................................................... 12

Table3.StateofMichiganstandardeffluentqualitystandards.Note,thesearegeneralandaresubjecttochangeduringtheNPDESpermittingprocess. ........................................................... 13

Table4.EPAsuggestedmonitoringguidelinesfortestingfrequencyofwaterdesignatedasUrbanReuse............................................................................................................................................................. 13

Table5.IonconcentrationsofEastLansingWastewaterTreatmentplanteffluent. .............. 18

Table6.Alistofsuggestedlimitsforwidevarietyofelementsknowntobeharmfultovariousdifferentwildlifeandorganisms.................................................................................................... 19

Table7.Summaryofliquidindustrialwastegeneratorquantitybasedregulations(CourtesyofMDEQ). ............................................................................................................................................ 46

Table8.SummaryofCosts. ............................................................................................................................... 52

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INTRODUCTION

Problem Definition The purpose of this project was to design and demonstrate an innovative water reclamation system for the MSU campus. It was required that our innovative system:

1. Minimize waste generation

2. Be cost effective

3. Be capable of being permitted from a regulatory standpoint and acceptable to the general public

4. Consider all residuals generated to insure that Federal Regulations and Land Disposal are met.

5. Account for variations in the chemistry of wastewater and ensure that our system meets all Applicable and Relevant Appropriate Requirements.

The following assumptions were set for all participating project reams:

1. The entering our reclamation facility (i.e. East Lansing Waste Water Treatment Plant (ELWWTP) effluent) has been treated with preliminary treatment, primary sedimentation, activated sludge treatment, secondary clarification with ferric chloride to remove phosphate, and tertiary filtration.

After lengthy discussion and consideration of alternatives, TAP Engineering concluded that using reclaimed water for Forest Akers golf course irrigation was the most feasible and economically sound option. Therefore, the following report will demonstrate the design of a treatment facility for the use of Forest Akers golf course irrigation.

Background Forest Akers Golf Course currently utilizes well water pumped from a confined aquifer located below MSU’s campus. The same aquifer is used as MSU’s primary potable water supply. A considerable and increasing risk to much of the country’s drinking water supply involves aquifer depletion. Aquifer depletion is the process by which the rate of water withdrawal from the aquifer surpasses the rate of natural replenishment. In order to minimize any future conflicts involving the MSU’s potable water supply, a wastewater reclamation system was designed. The reclamation system was designed to reduce the current demand imposed on the local aquifer by supplying the golf course with reclaimed water for irrigation purposes.

Forest Akers Golf Course typically shuts down from the end of October to the 3rd week of the following April; no water is used in the winter. The golf course irrigates daily for approximately 200 days of the year. According to the historical data from 1998-2003, the golf course’s yearly average consumption was 38 million gallons per year (excluding abnormal year 2000) [5]. Average water needed on daily basis is approximately 0.3 MG considering a 1.5 design safety

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factor. The East Lansing Wastewater Treatment plant average effluent of 13.3 MGD is enough to cover the quantities needed for the golf course.

Effluent water quality data from May 2007-June 2008 was supplied by the East Lansing Wastewater Treatment Plant (ELWWTP). Relevant water quality data supplied included: coliform, pH, biological oxygen demand, dissolved oxygen, suspended solids, phosphorus, ammonia, chloride residual, cyanide, thallium, mercury and mercury. An effluent sample was provided by ELWWTP and the sodium, calcium and magnesium concentrations were determined using Flame Atomic Adsorption.

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LEGAL AND REGULATORY ISSUES

There are no federal regulations governing water reclamation and reuse in the U.S.; the regulatory burden rests within the states [1]. The only water reuse guidelines currently set in place by the state of Michigan are for agricultural food crop and agricultural non-food crop use [2]. Therefore, it is likely that T.A.P. Engineering and the Michigan Department of Environmental Quality (MDEQ) would have to work synergistically in order to establish reasonable state requirements. Given that this is not possible for the scope of this project, T.A.P. Engineering adopted the guidelines set forth by the US Environmental Protection Agency (EPA). Assuming that our system would be classified as Urban Reuse (typically considered the classification for golf course irrigation), the EPA’s suggested water quality standards for are as stated in Table1.

Table 1. EPA suggested water quality standards for Urban Reuse purposes. Quality Parameter Limits

pH 6-9

BOD < 10 mg/L

Turbidity < or = 2 NTU

Fecal Ecoli None detectable

Cl2 residual 1 mg/L minimum

Table 2. Summary of our relevant effluent quality Quality Parameter Our Effluent

pH 6.3-8.0

BOD <10 mg/L

Choliform 429 (avg)

Cl2 0.01-0.03

In Michigan, Part 4 of Part 31 of the Water Resources Protection, of Act 452 of 1994 sets water quality standards that are to be met in all waters of the state. A summary of Michigan’s standards can be found in Table3. These however, may not be the only enforceable standards for a particular operation. According to their website, the MDEQ requires “anyone discharging, or proposing to discharge waste or wastewater directly into the surface waters of the United States…to obtain an NPDES permit”. The conditions of the NPDES permit are often project specific, which can result in additional enforceable standards. In our case however, we are not

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directly discharging pollutants into surface waters, instead, we are irrigating landscape, which in turn would route the discharges into sanitary sewers, which does not require a permit [4].

Table 3. State of Michigan standard effluent quality standards. Note, these are general and are subject to change during the NPDES permitting process.

Michigan Effluent Standards Limits

pH 6.5-9

BOD/DO 5 mg/L warmwater fishery

or 7 mg/L coldwater fishery

Phosphorus 1 mg/L (monthly average)

Coliform

200 CFU/100ml as monthly average

and

400 CFU/100ml as weekly average

Total Suspended Solids 30 mg/L as monthly average

and 45 mg/L as 7-day average

Table 4. EPA suggested monitoring guidelines for testing frequency of water designated as Urban Reuse.

Parameter Testing Frequency

pH Weekly

BOD Weekly

Turbidity Continuous

Coliform Daily

Chloride Residual Continuous

Riparian Rights in Michigan A riparian user is not entitled to make any use of the water that substantially depletes the stream flow or significantly degrades the quality of the stream [2]. Our proposed design is estimated to use roughly 0.3 MGD of the total 13 MGD of effluent that is typically discharged by the ELWWTP. Thus, we are using, on average, only 2% of the total discharge volume which is

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assumed and hereby considered sufficiently low enough to not significantly degrade the quality of the stream or significantly deplete the stream flow.

Water Ownership To date, only a few states have clearly defined water rights to reclaimed water, in most states this is still an unsettled area of the law. An example of a state with clearly defined laws could be California. There, a permit from the State Water Resources Control Board (SWRCB) is required prior to changing the point of discharge, place of use, or purpose of use [1]. In general, the owner of the wastewater treatment plant that produces the effluent is considered the owner of the effluent water and is thus considered to have first rights to its use and is not usually bound to continue its discharge. However, certain scenarios may arise when in fact the WWTP is restricted in its effluent use [1]:

• Reduced Discharge-the reallocation or limitation of effluent discharge flows could spawn legal issues from downstream users if the relocation or limitation inflicts serious economic losses or negative environmental impacts.

• Reduced Withdrawal-a reuse program that reduces withdrawal on local water sources will probably pose no third party conflicts with respect to water rights issues, but the situation should still be considered.

An evaluation of the two scenarios above yields the conclusion that it is unlikely that any water ownership issues will arise in this instance. Our reduction in discharge quantity is minimal and will likely have little effect on downstream conditions. Furthermore, considering that the implementation of our proposed project will reduce demand on a local water source further suppresses the likelihood of any third party water rights issues.

Monitoring Requirements The EPA publication “Guidelines for Water Reuse” also provides monitoring guidelines that are to be followed. These are summarized in Table4.

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Summary There are currently no federal regulations governing water reclamation and reuse in the U.S.; the regulatory burden rests within the states. Michigan currently does not have any regulation or guidelines set forth for the use of reclaimed water for golf course irrigation. Therefore, TAP Engineering adopted the water quality and water quality monitoring requirements set forth by the US Environmental Protection Agency. Our proposed project would not need and NDPES permit. The estimated reclaimed discharge is sufficiently low enough to inhibit the manifestation of riparian water right and water ownership conflicts.

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EFFLUENT QUALITY CONSIDERATIONS

The EPA outlines a wide number of water contaminates commonly found in reclaimed water that are potentially dangerous to a wide number of plants and organisms (see

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Table 6). In our case however, we are dealing with a very specific customer with a limited number of potentially affected species (predominately bent grass or bluegrass). Furthermore, the testing of all the listed contaminants is very time consuming and expensive, thus it was considered out of the scope of this project to test for all the stated contaminants. The contaminants of elevated importance were tested and will be discussed in the proceeding section.

Federally Regulated Contaminants The ELWWTP was assumed to be in accordance with all state and federal water quality regulations. Therefore, it was assumed that the concentrations of state and federally regulated contaminants such as mercury, arsenic, nitrogen, and thallium were below the legal limit.

Nitrogen and Phosphorus Nitrogen and phosphorus containing fertilizers are commonly added to turfgrass, as they are essential nutrients to plant growth. Wastewater effluent often contains relatively significant concentrations of nitrogen and phosphorus. Not surprisingly, has been shown that turfgrass quality under effluent irrigation may be the same as or better than turf irrigated with potable water that was supplemented with Nitrogen-Phosphorus-Potassium fertilizer. In fact, the economic values of these nutrients within the reclaimed water can be of substantial economic value [1]. Therefore, it was assumed that the nitrogen within the effluent wastewater is of beneficial use, not a hazardous contaminant deserving of removal consideration.

Chloride and Coliform Tables 1 and 2 display the EPA’s guidelines and our effluent water quality, respectively. When analyzing these two tables, one can clearly see that our chloride residual as well as our fecal coliform removal both need to be significantly increased.

Sodium Adsorption Ratio A few known problematic effluent constituents include sodium and suspended solids. Elevated salinity typically does not have adverse effects in the short-term plant quality, but can cause issues when applied over long periods of time. When salts are applied over a long period of time, especially sodium, they can replace valuable ions such as calcium, magnesium, or potassium and break down break down the structure of the soil. More specifically, elevated sodium content causes deflocculation of the soil clay particles, which in turn severely reduces both soil aeration and water infiltration and percolation. The effects of elevated effluent salt contents on the irrigation of soils is often evaluated using Soil Adsorption Ration (SAR). The SAR is a ratio of sodium ion concentration to that of calcium plus magnesium. The following equation is used to calculate the SAR [1]:

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(1)

where the ion concentrations are expressed in meq/L. High SAR values (>9) can cause severe permeability problems. On the other hand, very low ionic concentration can have severe effects on the soil, as it may dissolve valuable ions (e.g. calcium) from the soil, which in turn could damage the plant.

Table 5. Ion concentrations of East Lansing Wastewater Treatmentplant effluent.

Species ppm meg/L

Calcium 110 5.5

Magnesium 30 2.5

Sodium 270 11.7

SAR 5.89

EC 1.048 dS/cm

Often times SAR and the electrical conductivity (EC) (EC is used to estimate the total dissolved solids concentration) are looked at together in order to evaluate if any salt related issues that may arise. For SARs between 3 and 6 with EC between 1.2-.03, the EPA suggests a slight to moderate restriction of water reuse. However, one should note that for EC’s above 1.2 with SARs between 3 and 6, there is no recommended restriction [1]. Considering the close proximity of our product water quality to the quality needed for negligible use restrictions (see Table5), we will hereby assume that our water is close enough to the qualities needed in order to neglect any use restrictions.

The type of grass that dominates Forest Akers is known as annual bluegrass [5] and it is known to be sensitive to larger values of EC (should be <3 dS/m). Accordingly, given that our EC well below what is considered the “sensitive” limit of annual bluegrass, we’ve concluded that a salt content removal process, such as nanofiltration or reverse osmosis will not be necessary for the proposed project. In fact, if such process were implemented, it is likely that the water would require resalinification as the lack of ion concentration in the product water results in the extraction of salt ions from the soil and roots, to the product irrigation water. Thus the implementation of membrane technologies in this instance is unwarranted and would most likely significantly increase the process cost.

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Table 6. A list of suggested limits for wide variety of elements known to be harmful to various different wildlife and organisms.

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Summary A few known potentially problematic effluent constituents include phosphorus, nitrogen, salts, and suspended solids. Nitrogen and phosphorus are vital plant nutrients, so removal of these constituents was not needed. Both chloride residual and coliform removal need to be increased in order to meet the EPA’s suggested water quality. The effects of elevated salt concentrations in the reclaimed water on irrigated soils is often evaluated using the SAR. Typically, SAR and the EC are looked at together in order to predict any potential salt related issues. Considering the close proximity of the ELWWTP effluent water quality to the quality needed for negligible use restrictions (see Table5), it was assumed that the ELWWTP effluent was close enough to the qualities needed to neglect any use restrictions. Furthermore, the implementation of membrane technologies is unwarranted and would most likely significantly increase the process cost.

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COMPARISON OF DISINFECTION TECHNOLOGIES

A general comparison of the disinfection technologies is presented below. The CrT values differ with both temperature and pH. The characteristics of the reclaimed water and the degree of treatment required decide the appropriate disinfection technology to be utilized for maximum effectiveness. Deciding factors in the selection of a disinfectant are 1) Economic evaluation 2) Public and operator safety 3) Environmental effects, and 4) Ease of operation.

Advantages and disadvantages of chlorine, chlorine dioxide, ozone and UV radiation:

Chlorine Advantages:

1. Well-established technology 2. Effective disinfectant 3. Chlorine residual can be monitored and maintained 4. Combined chlorine residual can also be provided by adding ammonia. 5. Germicidal chlorine residual can be maintained in long transmission lines. 6. Availability of chemical system for auxiliary uses such as odor control, dosing RAS,

and disinfecting plant water systems. 7. Oxidizes sulphides. 8. Capital cost is relatively inexpensive, but cost increases considerably if conformance

to Uniform Fire Code Regulations is required. 9. Available as calcium and sodium hypochlorite that are safer than chlorine gas. 10. Can be generated on-site.

Disadvantages:

1. Hazardous chemical that can be a threat to plant workers and public; strict safety measures must be employed in light of Uniform Fire Code Regulations.

2. Relatively long contact time required. 3. Combined chlorine is less effective for inactivating some viruses, spores and cysts at

low dosages. 4. Residual toxicity of treated effluent must be reduced through dechlorination. 5. Forms trihalomethanes and other DBPs. 6. Releases volatile organic compounds from chlorine contact basins. 7. Oxidizes iron, magnesium and other inorganic compounds (consumes disinfectant). 8. Oxidizes a variety of organic compounds. 9. Increases TDS level of treated effluent.

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10. Increases chloride content of treated effluent. 11. Acid generation; pH of the wastewater can be reduced if alkalinity is insufficient.

Chlorine Dioxide Advantages:

1. Effective disinfectant for bacteria, Giardia and viruses. 2. More effective than chlorine for inactivating most viruses, spores, cysts and oocysts. 3. Biocidal properties not affected by pH. 4. Under proper generation conditions, halogen-substituted DBPs not formed. 5. Oxidizes sulphides. 6. Provides residuals.

Disadvantages:

1. Unstable, must be produced on-site. 2. Oxidizes iron, magnesium and other inorganic compounds (consumes disinfectant). 3. Oxidizes a variety of organic compounds. 4. Forms DBPs (chlorite and chlorate) limiting applied dose. 5. Potential for the formation of halogen-substituted DBPs. 6. Decomposes in sumlight. 7. Can lead to the formation of odors. 8. Increases TDS level of treated effluent. 9. Operating costs can be high.

Ozone Advantages:

1. Effective disinfectant 2. More effective than chlorine in disinfecting most viruses, spores, cysts and oocysts. 3. Biocidal properties not affected by pH. 4. Shorter contact time than chlorine. 5. Oxidizes sulphides. 6. Requires less space. 7. Contributes dissolved oxygen 8. At higher dosages than required for disinfection, ozone reduces the concentration of

trace organic matter.

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Disadvantages:

1. Ozone residual monitoring and recording requires more operator time than for chlorine residual.

2. No residual effect. 3. Less effective in inactivating some viruses, spores, cysts and oocysts at low dosages

used for coliform organisms. 4. Forms DBPs 5. Oxidizes iron, magnesium and other inorganic compounds (consumes disinfectant). 6. Oxidizes a variety of organic compounds. 7. Off-gas requires treatment. 8. Safety concerns 9. Highly corrosive and toxic. 10. Energy intensive. 11. Relatively expensive. 12. Highly operational and maintenance sensitive.

UV radiation Advantages:

1. Effective disinfectant. 2. Requires no hazardous chemicals. 3. No residual toxicity. 4. More effective than chlorine in inactivating most viruses, spores and cysts. 5. No formation of DBPs at dosages used for disinfection. 6. Does not increase TDS level of treated effluent. 7. Effective in the destruction of resistant organic constituents such as NDMA 8. Improved safety 9. Requires less space than chlorine disinfection.

Disadvantages

1. No immediate measure of whether disinfection was successful. 2. No residual effect. 3. Less effective in inactivating some viruses, spores, cysts at low dosagesused for

coliform organisms. 4. Energy intensive. 5. Hydraulic design of UV system is critical. 6. Capital cost is relatively inexpensive, but price is coming down as new and improved

technology is brought to the market.

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7. Large number of UV lamps required where low-pressure low-intensity systems are used

8. Low-pressure low-intensity lamps require acid washing to remove scale. 9. Lacks a chemical system that can be adapted for auxiliary uses such as odor control,

dosing RAS, and disinfecting plant water systems. 10. Fouling of UV lamps. 11. Lamps require routine periodic replacement 12. Lamp disposal is problematic due to presence of mercury.

Summary Both chlorination and UV radiation are commonly used to treat wastewaters. UV radiation is a newer technology as opposed to the established chlorination disinfection. We have chosen chlorine as a disinfectant over UV radiation due to the multiple problems associated with UV lamps such as fouling, scaling etc and the higher capital cost of its installation. Chlorination is a safer, popular method of disinfection. For our treated water uses, chlorine would effectively disinfect the water to within permissible levels. Chlorine is not that maintenance sensitive and can function well once fully calibrated. All the various aspects of chlorine residual and by-product formation can be negated by making necessary considerations and taking measures for it in the treatment design.

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THEORY OF CHLORINATION DISINFECTION

The main purpose of disinfection process is to achieve removal and/or inactivation of pathogenic organisms. The main pathogenic organisms in wastewater are bacteria, protozoan oocysts and cysts, helminthes and viruses. Dechlorination is the process by which chlorine is used for disinfection. The theory and application of dechlorination is presented in the following discussion.

Basic Chemistry Chlorine and Chlorine Compounds. Chlorine may be used as a disinfectant in the form of compressed gas under pressure that is dissolved in water at the point of application, solutions of sodium hypochlorite, or solid calcium hypochlorite. The three forms are chemically equivalent because of the rapid equilibrium that exists between dissolved molecular gas and the dissociation products of hypochlorite compounds. The relative amount of chlorine present in chlorine gas, or hypochlorite salts, is expressed in terms of available chlorine. The concentration of hypochlorite (or any other oxidizing disinfectant) may be expressed as available chlorine by determining the electrochemical equivalent amount of Cl2 to that compound. The equation below shows that 1 mole of elemental chlorine is capable of reacting with two electrons to form inert chloride:

Equation 2 shows that 1 mole of hypochlorite (OCl−) may react with two electrons to form chloride:

OCl− + 2e− + 2H+ = Cl− + H2O (2)

Hence, 1 mole of hypochlorite is electrochemically equivalent to 1 mole of elemental chlorine, and may be said to contain 70.91 g of available chlorine (identical to the molecular weight of Cl2). The molecular weights of Ca(OCl)2 and NaOCl are, 143 and 74.5, respectively, so that pure preparations of the two compounds contain 99.2 and 95.8 weight percent available chlorine; hence, they are effective means of supplying chlorine for disinfection purposes. When a chlorine-containing compound is added to water containing insignificant quantities of kjeldahl nitrogen, organic material, and other chlorine-demanding substances, a rapid equilibrium is established among the various chemical species in solution. The term free available chlorine is used to refer to the sum of the concentrations of molecular chlorine (Cl2), hypochlorous acid (HOCl), and hypochlorite ion (OCl−), each expressed as available chlorine.

Cl2 + 2e− = 2Cl− (1)

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The dissolution of gaseous chlorine to form dissolved molecular chlorine is expressible as a phase equilibrium, and may be described by Henry’s law:

Cl2(g) = Cl2(aq) H(mol/L-atm) = [Cl2(aq)]/PCl2 (3)

where quantities within square brackets represent molar concentrations, PCl2 is the gas phase partial pressure of chlorine in atmospheres, and H is the Henry’s law constant, estimated from the following equation [10]:

H = 4.805 × 10−6 exp( 2818.48/T (mol/L-atm))

(4)

Dissolved aqueous chlorine reacts with water to form hypochlorous acid, chloride ions, and protons as indicated by Equation 5.

Cl2(aq) + H2O = H+ + HOCl + Cl− (5)

(6)

This reaction typically reaches completion in 100 ms [11,12] and involves elementary reactions between dissolved molecular chlorine and hydroxyl ions. The extent of chlorine hydrolysis decreases with decreasing pH and increasing salinity. Therefore, the solubility of gaseous chlorine may be increased by the addition of alkali or by the use of fresh, rather than brackish, water. Hypochlorous acid is a weak acid and may dissociate according to Equation 7:

HOCl = OCl− + H+ (7)

Ka = [OCl−][H+]/[HOCl] (8)

Reactions with Ammonia. Chlorine reacts with ammonia and amino nitrogen compounds dissolved in water to form chloroamines. In the presence of ammonium ion, free chlorine reacts in a stepwise manner to form chloramines. This process is depicted in Equations 9-11:

NH4+ + HOCl = NH2Cl + H2O + H+ (9)

NH2Cl + HOCl = NHCl2 + H2O (10)

NHCl2 + HOCl = NCl3 + H2O (11)

These reactions are dependent on the pH, temperature and contact time, and on the ratio of chlorine to ammonia. Free chlorine not only reacts with ammonia but is also a strong oxidizing agent. The terms total available chlorine and total oxidants refer, respectively, to the sum of free

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chlorine compounds and reactive chloramines, or total oxidating agents. Usually enough chlorine is added to react with all oxidizable substances, such that if additional chlorine is added it will remain as a free residual. This ensures that complete disinfection has taken place. The amount of chlorine that must be added to reach a desired level of residual is called chlorine demand. Reactions with Organic Matter. Organic amines react with free chlorine to form organic monochloramines. Organic chloramines may also be formed by the direct reaction between monochloramine and the organic amine, and this is apparently the most significant mechanism of organic N-chloramine formation at higher concentrations such as might exist at the point of application of chlorine to a water [15]. Pure solutions of amino acids and some proteins yield breakpoint curves identical in shape to those of ammonia solutions [16,17]. Reactions with Other Inorganic Compounds. Reactions of free chlorine with inorganic compounds are generally first order in both the oxidizing agent (hypochlorous acid or hypochlorite anion) and the reducing agent. Nitrites present in partially nitrified waters react with free chlorine via a complex, pH-dependent mechanism [19]. Dechlorination. When the chlorine residual in a treated water must be lowered prior to distribution, the chlorinated water can be dosed with a substance that reacts with or accelerates the rate of decomposition of the residual chlorine. Compounds that may perform this function include thiosulfate, hydrogen peroxide, ammonia, sulfite/bisulfite/sulfur dioxide, and activated carbon; however, only the latter two materials have been widely used for this purpose in water treatment [26]. . Chick’s Law and Elaborations. Disinfection is analogous to a bimolecular chemical reaction, with the reactants being the microorganism and the disinfectant, and can be characterized by a rate law as are chemical reactions:

r = −kN (12)

where r is the inactivation rate (organisms killed/volume-time) and N is the concentration of viable organisms. In a batch system, this results in an exponential decay in organisms, because the rate of inactivation equals dN/dt, assuming that the rate constant k is actually constant (e.g., the disinfectant concentration is constant). Watson (1908) proposed Equation 14.28 to relate the rate constant of inactivation k to the disinfectant concentration C [27]:

k = k′Cn (13)

where n is termed the coefficient of dilution and k′ is presumed independent of disinfectant concentration, and, by virtue of Equation 14.27, microorganism concentration. From the Chick-Watson law, when C, n, and k′ are constant (i.e., no demand, constant concentration), the preceding rate law may be integrated so that in a thoroughly mixed batch system,

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ln(N/N0) = −k′Cnt (14)

where N and N0 are, respectively, the concentrations of viable microorganisms at time t and time 0. If n=1, the above equation can be rewritten as follows:

1/k’ ln(N/N0) = Ct = D (15)

Where D = germicidal dose for a given degree of inactivation (Mg.min/L). The performance of disinfection is based on the amount of dose (concentration multiplied by time).

Mode of Action of Chlorine Free chlorine at low pH has been known to be more biocidal than free chlorine at high pH. Once taken into the environment of the living organism, chlorine may enter into a number of reactions with critical components causing inactivation. In bacteria, respiratory, transport, and nucleic acid activity are all adversely affected. In bacteriophage f2, the mode of inactivation appears to be disruption of the viral nucleic acid [28].

Forms of Chlorine Application Chlorination. Chlorine may be obtained for disinfection in three forms, as well as generated on-site. For very small water treatment plants, solid calcium hypochlorite (Ca(OCl)2) can be used. This can be applied as a dry powder, or in proprietary tablet dispensers. Calcium hypochlorite is more expensive than the other chemical forms, and particularly in hard waters, its use can lead to scale formation. Generally, the least expensive form at large usage rates is liquefied chlorine gas. The use of liquefied chlorine gas carries with it certain risks associated with accidental leakage of the gas. As a result, a number of utilities have elected to use the somewhat more expensive sodium hypochlorite (NaOCl) as a source of disinfectant. Sodium Hypochlorite. NaOCl is only available as a liquid and usually contains 12.5 to 17 percent available chlorine at the time it is manufactured. It can be purchased in bulk or manufactured onsite; however, the solution decomposes more readily at high concentrations and is affected by exposure to light and heat. It must therefore be stored in a cool location in a corrosion-resistant tank. Another disadvantage of NaOCl is the chemical cost. The purchase price may range from 150 to 200 percent of the cost of liquid chlorine. The handling of liquid sodium hypochlorite requires special design considerations because of its corrosiveness, the presence of chlorine fumes, and gas binding in chemical feed lines. Several proprietary systems are available for the generation of sodium hypochlorite from sodium chloride or seawater. On-site generation systems have been used only on a limited basis, typically at relatively large plants, due to their complexity and higher power cost.

Source Water Chlorination/Preoxidation. Prechlorination, the addition of chlorine at an early point within treatment, is designed to minimize operational problems associated with biological

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slime formation on filters, pipes, and tanks, and also release of potential taste and odor problems from such slimes. In addition, prechlorination can be used for the oxidation of hydrogen sulfide or reduced iron and manganese. Probably the most common point of addition of chlorine for prechlorination is the rapid mix basin (where flocculant is added). However, due to present concerns for minimizing the formation of chlorine byproducts, the use of prechlorination is being supplanted by the use of other chemical oxidants (e.g., ozone, permanganate) for the control of biological fouling, odor, or reduced iron or manganese. Postchlorination. Postchlorination, or terminal disinfection, is the primary application for microbial reduction. It has been most common to add chlorine for these purposes either immediately before the clear well or immediately before the sand filter. In the latter case, the filter itself serves, in effect, as a contact chamber for disinfection. The distribution system itself, from the entry point until the first consumer’s tap, provides additional contact time. Superchlorination/Dechlorination. Some poor quality waters have organic compounds that react with chlorine to form toxic compounds that adversely affect the quality of treated water. In the process of superchlorination/dechlorination, chlorine is added beyond the breakpoint to react with all the ammonia nitrogen. Generally, the residual chlorine obtained at this point is higher than may be desired for distribution. The chlorine residual may be decreased by the application of a dechlorinating agent such as sulfur compounds which reduces the residual chlorine or adsorption on and reaction with activated carbon. Chloramination.Chloramination, the simultaneous application of chlorine and ammonia or the application of ammonia prior to the application of chlorine, resulting in a stable combined residual, has been a long-standing practice at many utilities.

Summary Chlorination is the process of disinfecting water by adding chlorine in the form of liquefied chlorine, sodium hypochlorite or calcium hypochlorite. Chlorine reacts with water to form hypochlorous acid and hydrochloric acid which further dissociate to give hypochlorite, chloride and hydrogen ions. Formation of hydrogen ions causes a decrease in the pH and addition of alkali may be necessary to maintain the pH of water. Chlorine reacts with ammonia and amino nitrogen compounds dissolved in water to form chloramines. Usually enough chlorine is added to oxidize all the ammonia and amino nitrogen compounds present in the water as this ensures complete disinfection. The chlorine residual is monitored and kept within safety limits. Chlorine residual may be decreased by dechlorination processes such as adsorption onto activated carbon. Free chlorine also reacts with some organic and inorganic matter to form disinfection-byproducts(DBPs). Formation of DBPs can be minimized by adding excess ammonia so that all the chlorine in water is present in a combined form.

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DISINFECTION PROCESS DESIGN A NaOCl (sodium hypochlorite) chlorination system was designed to treat tertiary filtration effluent. The design flows are 0.3 MGD (1153.8 m3/d), which is part of the total available 13.3 MGD effluent. The influent to the disinfection system is expected to contain an average of 430 fecal coliform/100ml, with a peak of 60000 coliform/ 100ml. The effluent coliform standards are set as “no detectable fecal coliform” as stated previously, which mean the number of fecal coliform organisms should not exceed 14/100 ml in any sample. It is also desired have minimum effluent chlorine residual of 1mg/L Cl2.

Sizing Chlorination Facilities The first thing to design the chlorination facilities and equipment is to know the dosage to which NaOCl is to be applied. Use of the CT concept to control the disinfection process is predominant in the United States. In some states, the CT value and the contact time are specified in regulatory requirements. For example, the state of California requires a CT value of 450mg min/L and a modal contact time of 90 min at peak flow for certain reclamation application. When the residual in the effluent is specified or the final number of coliform bacteria is limited, onsite testing is preferred to determine the dosage. In this preliminary design, we are calculating the dosage based on CT approach.

Assuming we have the conditions of initial effluent chlorine demand 4mg/L; demand due to decay during chlorine contact 2.5 mg/L; required contact time 60 mins.

Estimate the required chlorine residual using the following equation:

€

N /N0 = (Ct /b)−n

Use the typical values given above for the coefficients.

b=4.0

n=2.8

C=0.15 mg/L

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The required dosage= 4.0mg/L+ 2.5mg/L+ 0.15 mg/L=6.65 mg/L

According to the EPA Design Manual Municipal Wastewater Disinfection, treatment of sand filter effluent to reduce initial coliform 100-10000/100ml to lower than 2.2/100ml require a dosage of 8-18 mg/L. To ensure coliform organisms do not exceed 14/100 ml in any sample, we arbitrarily chose 10mg/L from the range that is higher than the calculated value. Since Michigan dose not have a specific regulation, we check this with the regulation of California. A dosage of 10mg/L with a contact time of 90 mins has a CT value of 900 mg mins/L which satisfies the regulations.

The capacity of the chlorinator and storage tank is calculated as follows:

Chlorine is supplied as 10 percent NaOCl solution, therefore

Daily NaOCl Volume=

The shipping time for the vendor is 3days and assumes a 15-day emergency reserve. Storage volume can then be calculated as

Storage volume= (3+15) *0.115= 2 m3

Correcting for NaOCl decay

18*0.031=0.558

Chlorine Contact Basin Design Contact Basins are to be designed to ensure that some defined percentage of the flow remains in the basin for the design contact time to ensure effective contact between the disinfecting agent

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and the liquid. The contact time is usually regulated by specific agency in the range from 30-120mins. Since Michigan dose not have a regulation on this, we adopt the value specified by the State of California; 90mins.

A Baffled serpentine contact chamber was chosen as the basin configuration. Baffles will be placed at the beginning of each pass. The contact basin was designed based on dispersion as follows:

Assume trial cross-sectional dimensions for the chlorine contact basin and determine the corresponding length and velocity to achieve a dispersion number of about 0.015.

Assume dimensions Width=0.75m, Depth=1.5m, Number of channels=2

The Velocity

The required length

The Reynolds Number can be computed as

Compute the coefficient of dispersion

Determine the dispersion number

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Which is lower than 0.015.

In this contactor design L/W ration will be 42.6 which is the around the preferable value of 40. Submerged baffles will be placed in the beginning of each channel to break up density current; limit short circuiting and minimize the effect of hydraulic dead space.

The channel number of two satisfies the reliability and redundancy requirement to facilitate maintenance and cleaning. When light flocculent accumulated in the basins to a certain extent, one basin could be removed from service so that the accumulated solids can be removed.

Dosage Control Flow meter or chlorine residual analyzer can be used to pace the chlorine flow rate to the wastewater flow rate or to control the dosage by automatic measurement of chlorine residual. In the compound system in our design, the control signals obtained from the flow meter and from the residual recorder are fed to a programmable logic controller (PLC); this provide more precise control of the chlorine dosage and residual.

Initial Mixing Other conditions being equal, effective mixing is one of the most important factors to achieve effectiveness. Diffuser is common and cheap, but it is not very effective. To get best performance, chlorine is expected to be introduced and mixed ideally in less than a second. To achieve this goal, an injector pump type mixer will be used as shown in the following figure.

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Figure 1. Injector Pump Type Mixer [29]

Chlorine Residual Excess chlorine may occur from accidental overdosing or from intentional addition of large quantities of chlorine to accelerate disinfection. Low level chlorine residual can have potential toxic effect. Chlorine in excess of a desirable concentration of free residual chlorine typically in the range 0.2-1ppm should be removed. Since we have an effluent minimum residual of 1.0 mg/L and we are using programmable logic controller to control the feeding rate, we are not necessarily need to include a dechlorination component in our system. Instead, we included an ammonia addition system to convert free residual chlorine to combined residual chlorine.

Ammonia is usually added to water immediately after chlorination to provide more stable chlorine residual. Chloramines are less reactive than free chlorine and thus can persist for longer period. Ammonia is used to arrest the formation of disinfection byproducts. Aqua ammonia is most commonly used and is cheaper than anhydrous ammonia when lower quantities are needed. The storage tank should be a permanent onsite facility and should have enough storage for at least 10 days of maximum usage. Very good mixing is required to ensure efficiency.

Assuming we are using a 20% aqua ammonia (as weigh as nitrogen by volume) to convert the 1mg/L free chlorine residual to chloramines.

Daily free residual chlorine = (1g/m3) (1153.8m3/d) (1kg/1000g) =1.2kg/d

Ammonia added should have chlorine to ammonia mole ratio of 1 (weight ratio 5.07)

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Ammonia needed per day = (1.2kg/d)/5.07=236.6g/d as nitrogen

Aqua ammonia solution needed = (236.6 g/d) / (200g/L) =1.2 L/day

Storage tank volume = (1.2L/day) (10days) =12 L

Others Considerations A chlorine residual measurement will be taken at the contact basin outlet to ensure compliance with the regulatory agency requirement. The final sample will also be analyzed for bacteria using standard laboratory procedures.

Summary The sodium hypochlorite chlorination system is to treat tertiary filtration effluent with a design flow of 0.3 MGD (1153.8 m3/d), which is part of the total available 13.3 MGD effluent. The objective was to reduce the fecal coliform concentration from an as received average of 430 fecal coliform/100ml, (peak of 60000 coliform/100ml) to “no detectable fecal coliform” which means the number of fecal coliform organisms should not exceed 14/100 ml in any sample. The desired minimum effluent chlorine residual was 1mg/L Cl2.

A programmable logic controller (PLC) was used to precisely control the chlorine dosage and residual using the signals from flow meter and residual analyzer. An injector pump type mixer was used to maximum contact. Since we have a stable effluent flow, a required residual of 1mg/L and the programmable logic controller, we do not have to include a dechlorination unit but we do have an ammonia system to convert free residual chlorine to combine residual chlorine to arrest the formation of disinfection byproduct. A summary if the system design parameters can found in Table7.

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Table 7. Design Parameters for the sodium hypochlorite chlorination system

Design Parameters Values

Disinfectant Concentration 10mg/L NaOCl

Contact Time 10mins

CT Value 900 mg mins/L

Daily Disinfectant Consumption 115 L/d NaOCl

Disinfectant Storage Tank 2.1m3

Contact Basin Channels Number 2

Contact Basin Width 0.75m

Contact Basin Depth 1.5m

Contact Basin Length 32m

Daily Ammonia Consumption 1.2L 20% Aqua Ammonia

Ammonia Storage Tank 12L

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Figure 2. Schematic flow diagram for sodium hypochlorite chlorination

Receiving Water

Wastewater Effluent

Flowmeter

Chlorine Solution

Chlorine Residual Analyzer

Liquid Sodium Hypochlorite

Injector

Control Signal

Injector

Effluent Water

Liquid Sodium Hypochlorite

Storage

Feed Pump

Pump

Pulsation Dampner

Back-Pressure

Valve

Mixer

Aqua NH3 Storage tank

Control Signal

Programmable Logic Controller

Mixer

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ADDITIONAL DESIGN PROCESSES

Compensation for Elevated Salt Concentrations Sodium accumulation of soils can be controlled through the use of various amendments such as gypsum and sulfur. These are typically inexpensive materials that can be ground fine enough to be watered into the soil. The amount of such materials applied depends on how much Na is on the cation exchange sites. A useful table for determining the amount of gypsum needed is shown below (see Figure3).

Figure 3. Amounts of Gypsum and Sulfur required to replace indicated amounts of exchangeable sodium

The use of Figure3 requires the knowledge of the exchangeable sodium per 100 grams of soil (ESP). Since ESP could not be directly measured, a correlation between ESP and SAR was used [7]:

(16)

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Application of the above equation yields an ESP of 6.91. Multiplying by a factor of 1.25 in order to compensate for lack of quantitative replacement and rounding up, we have an ESP of 9. The total irrigatable acreage of the golf course is 64 acres [5]. Assuming that all the irrigatable acreage is irrigated with reused effluent water and that our arbitrary soil layer thickness is 6”, the total application rate of gypsum is 7.7 tons/acre-ft. With a price of around $5/ton [8], his would yield a total cost of around $3,000. It was found that it is better to frequently apply gypsum in lighter doses, as opposed to applying less frequently in larger doses [21]. Therefore, it will be assumed that gypsum will be applied monthly with the previously stated doses, as opposed to seasonally at elevated doses.

Operational Storage The purpose of operational storage facilities is to provide a reliable supply of water during periods of down time at the treatment plant, meet peak daily fluctuations in water demands and allow for optimum plant operation. Storage facilities can either be covered storage tanks or open retention ponds. When higher quality product water is needed, covered storage tanks should be used, as open retention ponds can produce lower water quality due to biological growth. However, for agricultural and golf course irrigation open retention ponds are considered adequate [3].

Storage facilities should be designed to hold 1.5-2 times the average summer day demand. Our average daily demand is 0.3 MGD. Converting this volume to cubic yards and multiplying by 2 yields a total volume of 3300 yards. Therefore, our total volume of excavation was assumed to be 3300 cubic yards.

It is known that Forest Akers has two retention ponds currently in place; an East pond and a West pond. Furthermore, it is known that the west course retention pond can be expanded, to a certain degree, without having to redesign the golf course [5]. The specific volume of the current retention pond as well as the total expandable area available was not obtainable; therefore, it was assumed that the west course pond had ample area for expansion and was used as our retention facility.

Delivery Systems During design, the designer should obtain both seasonal and diurinal estimates of the quanity and quality of water to be delivered. Our quantities available much surpass the daily need.

Pumping Systems The pumping facility(s) should be marked to indicate that it is a non-potable resource.

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Piping Non-potable pipelines will be properly identified and have adequate protection to avoid cross contamination. Non-potable pipe should be buried at least 1 ft deeper than the potable supply. All piping should have emboldened letters, integrally stamped and marked. Color-coded warning tape should be consistent throughout the area. Hose bibs discharging treated effluent should be secured to prevent any use form the public. The bibs should also be posted with signs reading “Reclaimed Water, Do Not Drink”.

Sprinklers Sprinkler selection and location require special consideration. Impact heads are considered less “cloggable” so should be used.

Flush Valves Flush valves should be installed in every irrigation system, particularly in low spots and at dead-ends.

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PUBLIC PERCEPTION

Public perception and public acceptance are of utmost importance when implementing water reuse projects. They can essentially make or break your project approval. Much research on public perception and acceptance of water reuse projects has been conducted. This includes numerous case studies on both successful and unsuccessful projects. It is our belief that proper acceptance via full project transparency and effective information relay is essential and will be the primary task involved with the marketing of this project. For this campaign we will likely adopt a model similar to that outlined by Hartley et al. (see

Figure 4. Planning initiative frameworkoutline[9].

PLANNING INITIATIVE FRAMEWORK

1 Manage information for all

2 Maintain individual motivation and demonstrate organizational commitment

3 Promote communication in a public dialog

4 Ensure fair and sound decision making

5 Build and maintain trust

Figure 4. Planning initiative framework outline [9].

Research has shown that a majority of the public is in favor of water reclamation/reuse. A survey conducted by Alpha Communications in 2001 showed that people overwhelmingly thought that water reuse was very beneficial, especially for golf courses (see Figure 5). Problems typically arise when there data sharing with the public is limited. An example could be the reclamation project set forth for the city of San Diego California. Improper data sharing spurred public discontent and eventually stopped the project. A successful example could the San Antonio Water Systems Reclamation Program. Although they too experienced public opposition, fairness and direct publicly visible actions assisted in overcoming the antagonism [9].

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Figure 5. Public opinion survey results on various uses of reclaimed water [2].

Manage Information for All We propose to use a variety of strategies in order to effectively manage project related information and news. This strategy will include the formation of a project related committee, an actively updated website, the hiring of experienced and established local press relations personnel, and the establishment of friendly media contacts. The fundamental purpose for the extensive list of information management items is to essentially “fill vacuum of information” [3]. If the proper authorities do not adequately provide the general public with ample data, then someone else will. The key is to provide enough information from the proper sources in order to prevent any such undesirable circumstances.

Maintain Individual Motivation and Demonstrate Organizational Commitment This task involves the use of water resource managers. This could include relevant personnel, Michigan Department of Environmental Quality personnel, Michigan Department of Natural Resources personnel, project engineers, etc. The target here is to demonstrate genuine commitment and to engage and hear the public and make certain that they understand that we take their concerns seriously [9].

Promote Communication in a Public Dialogue The core of this strategic element involves the formation of a Citizen’s Advisory Committee. The Committee would serve the purpose of providing in depth input on the project as well as

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reinforcing the notion that the public’s opinion is important and utilized. The committee should contain the following personnel [3]:

• Private citizens who are not likely to incur financial gain or loss greater than the average homeowner

• Representatives of public interest groups

• Public officials

• Citizens or representatives of groups with substantial economic interest in the project

A well functioning, well-organized committee will:

• Provide information from a group that is politically active in the community

• Raise questions to serve as valuable insight into questions that will be asked at other meetings

• Provide a sounding board for ideas

• Test market the public participation proves to determine it’s success

• Lend credibility to the process in the eyes of elected officials

Sound Decision Making All participants should agree that the decision making process and outcome are just, fair and sound. Sounds decisions are ones that are well thought out and are based upon accepted knowledge.

Build and Maintain Trust Diligence to the previous items will contribute to formation and maintenance of trust. It is also advisable to pursue the establishment of trust and credibility even when they are not necessarily needed. This should include the procurement of favorable media contacts and relations at the very early stages of project planning.

Summary It is our belief that via full project transparency and effective information relay are absolutely vital to gaining full public support and acceptance of our project. The following tasks will outline the core public relations strategy:

• Manage information for all

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• Maintain individual motivation and demonstrate organizational commitment

• Promote communication in a public dialog

• Ensure fair and sound decision making

• Build and maintain trust

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WASTEDISPOSAL

Precipitation in chlorine contact Basins A problem often encountered in the operation of chlorine contact basins is the formation and precipitation of a light flocculent material. The principal cause of the formation and precipitation of floc is the lowering of the pH that results from the addition of chlorine. The problem occurs most frequently where alum is used for phosphorus removal in separate precipitation facilities or is added before the effluent filters. For a variety of reasons including high pH and inadequate initial mixing, not all of the alum added reacts completely to form a floc that can be removed by precipitation or filtration. Thus, in addition to meeting reliability and redundancy requirements, a minimum of two chlorine contact basins is necessary to allow one basin to be removed from service so that the accumulated solids can be removed from the basins.

Waste Characterization The waste generated by the processes describe above falls under nonhazardous liquid waste according to Michigan’s Waste Management Guidelines. The key waste characterization tests we would expect to conduct are:

1. A Waste survey to identify waste streams (Our waste stream would primarily consist of the residue from the chlorine contact basin).

2. A paint filter test: This test is used to determine the presence of free liquid in a representative sample of the waste. A predetermined amount of material is placed in a paint filter. If any portion of the material passes through and drops from the filter within the 5-minute test period, it contains free liquids. If these wastes are not regulated under the hazardous waste regulations, they are regulated under Part 121 of Act 451 as a liquid industrial waste.

3. Toxicity Characteristic Leaching Procedure (TCLP): this test determines if the toxicity characteristics of the waste cause it to fall under the category of hazardous wastes. It can predict whether a waste is likely to leach chemicals into groundwater.

4. Flashpoint test: This determines if the waste is ignitable. 5. pH test – to determine if the waste is corrosive.

A copy of the waste characterization guidelines can be found in the Appendix.

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Depending on the amount of waste generated, the regulations applied on the waste would be determined. A summary of the regulations are listed below: Table 8. Summary of liquid industrial waste generator quantity based regulations (Courtesy of MDEQ).

In order to meet storage requirements, the following metrics must be met:

1. Containers need to be in a protected environment (away from weather, fire, physical damage and vandals)

2. Containers should have enough head space so that liquid doesn’t spill due to expansion in heat or contraction in cold.

3. Containers will be labeled legibly.

4. Containers must be kept closed.

Also, it we be required that the facility obtain a site identification number (if one is not already assigned to our site) before shipping waste off-site. (A site identification number is issued for a facility at a specific address and is used on waste manifests. If it isn’t known for sure if a business has a site identification number (some people call this an EPA ID number), or what regulated waste activities are on file with Waste and Hazardous Material Division, we would contact our District Office or search the Waste Data System (WDS) at www.deq.state.mi.us/wdspi.) We plan to contract one of the certified liquid transporters in Michigan (the list is given in here: http://www.michigan.gov/deq/0,1607,7-135-3312_7235---,00.html) to dispose the waste to a near-by landfill. The handling of the waste by the certified transport company is regulated under the Michigan guidance.

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SAFETYANDHEALTH

Operating and Handling Hypochlorite All those handling or oparting systems involving sodium hypochlorite systems should wear eye protection and have access to emergency eyewash and showers. The undiluted chemical can cause severe burns. All areas exposed to hypochlorite should be washed thoroughly.

Containers It will assumed that hypochlorite will be transported in 900 kg containers, which is believed to be the industry standard. 900 kg containers are moved, stored and used in the horizontal position. The valves on these containers are very similar to those on upright standard cylinder valves except for the absence of a fusible plug. There are a total of three fusible plugs located on each end of the 900 kg container. The valves on theses containers must be orientated vertically in order to allow for the withdrawal of the gas from the upper valve and liquid withdrawal from the lower valve.

Transportation Tank trucks for container transportation are available in 13600-18000 kg capacities are available. Also, “single-unit” rail cars are available in 14500, 27200, 50000, 77100, and 81500 kg capacities.

Facility Design Adequate space for proper loading and unloading of the 900 kg containers must be provided. Facilities handling 900 kg containers must comply with the same safety device, light, and ventilation requirements as those handling cylinders. An adequately designed 900 kg handling facility will have an overhead monorail hoist and a motorized trolley with at least 1800 kg capacity. The monorail should be appropriately designed to allow for transportation of the container from the supplier vehicle to its proper use or storage position.

Chlorine storage tank and chlorinator equipment rooms will be walled off from the rest of the plant and should be accessible only from the outdoors. Glass viewing window will be placed in the inside wall to check any leakage that may occur. Fan controls and air mask will be located in the entrance. The flow diagram is shown in the following figure.

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SITE CONSIDERATIONS

The ELWWTP is located in relative close proximity to the Forest Akers Golf course (see Figure6). It was assumed that the ELWWTP had ample space for the addition of a chlorination system. The product water will thus be produced on site and then transfered via an estimated 8000 ft of piping to the Forest Akers Golf course. There are two retention ponds located on the property of the golf course; and East one and West one. As stated in the “Operational Storage” section, the west pond can be expanded without having to redesign the layout of the course; it was thus assumed that this would provide the retention volume needed.

Figure 6. Site map of the project area (aerial photo courtesy of Google Maps).

WATERTREATMENT

PLANT

FORESTAKERSGOLFCOURSE

WETLANDS

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CONSTRUCTION PLANNING

Typical time requirement for the facilities planning through the completion of the plant’s first year operation is 6-8 years, and this is only true when project progress and approval is timely (see Table9). Design typically consists of facilities planning and actual design in preparation of documents for bidding and construction. The same engineer is retained for planning, design and construction to maximize efficiency. Our water reclamation system is a small plant that may require shorter time for implementation than those indicated in the table.

Table 9. Typical implementation time table for wastewater treatment plant

Activity Duration, months

Facilities Planning 8-12

Regulatory Approval 2-3

Preliminary Design 5-6

Value Engineering 1-2

Final Design 7-10

Regulatory Approval 2-3

Bidding 2-3

Contract Award 1-2

Construction 30-38

Start-up 2-5

First year operation 12

Total 72-96

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COSTS

Chlorination Literature pertaining to dechlorination unit process construction costs were not easily obtained. The most reliable data obtained was found in an EPA publication titled “Wastewater technology factsheet: Chlorination Disinfection”. A chart found within the document (see ) was used as the single cost estimation utility for our core disinfection process. The chart displays data collected from a 1995 survey for the average costs of secondary effluent disinfection treatment. The process specifics were not given, so it was assumed that the average costs were calculated using data for both free chlorine and combined chlorine process plants. Our expected chlorine dose was 10 mg/L using an average dry weather flow of 1 MGD, yielding an estimated capital cost of $441,000 and an estimated operation and management cost of $60,000, based on the data form Figure7. We will not be dechlorinating, therefore the cost incurred for a dechlorination process will not be considered.

The capacity considered for the price stated above is much higher than what our design calls for, so our estimated price was reduced by two thirds. Therefore, our estimated capital cost will be 30% of the value stated above; or $132,000. The uniform fire code costs for small systems can be as much as 25% more than what is given in Figure7. Therefore, adjusting for the scale of our operation and accounting for the 25% cost increase for small systems, our estimated uniform fire code compliance cost is roughly $100,000.

The operation and management cost estimation includes power consumption, cleaning chemicals and supplies, miscellaneous equipment repairs, and personnel costs. Again, since the estimates given in the figure below are for an operation of increased capacity, we will conservatively estimate our O&M costs to half what is given, or $30,000. Although limited resources were identified, the price of industrial grade sodium hypochlorite was $140 per cubic meter [22]. Based on an estimated daily consumption of 0.115 m3/day, the annual estimated sodium hypochlorite costs was $5,900.

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Figure 7. Estimated costs of chlorination treatment facilities [54]

Piping The distance between the ELWWTP and the Forest Akers Golf Course was conservatively estimated to be 8000 linear feet (LF) using Google Maps ©. The price per LF of standard 10” water piping was found to be $100/LF and the price per “Pipe Crossing” was found to be $655/LF [54]. This yielded a standard pipe distribution cost of $800,000. Special crossings are pipe crossing, such as railroads and roadways that require horizontal boring. Assuming a total of 4 crossings, the special crossing cost total was roughly $330,000. Summarizing, the total estimated distribution system costs was $1.1 million.

Excavation As stated above, excavation of the West retention pond is needed in order provide the operational storage needed for the irrigation system. The estimated total volume needed was 3300 yd3. Based on data from the Colorado Department of Labor and Employment [54], our total excavation costs are $32,000.

Gypsum As stated previously, the estimated cost per application of gypsum is roughly $3,000. Assuming five applications per year, our total annual gypsum costs are $15,000.

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Summary

Table 10. Summary of Costs.

Standard Piping Costs Pipe Diameter

(inches) Cost ($/LF) Total LF

Estimated Capital

Cost

10 100 8000 $ 800,000.00

Pipe Crossing Costs Pipe Diameter

(inches) Cost

($/inch dia./LF) Total LF Estimated Cost

10 655 500 $ 327,500.00

Excavation Costs

Unit Cost (per yd3)

Estimated Excavation

Volume (yd3)

Estimated Capital Cost

$10.67 3000 $32,010.00 Estimated Gypsum Cost

Cost/Application Estimated

Annual Applications

Estimated Annual Cost

$3,000.00 5 $15,000.00 Estimated Chlorination Cost

Estimated Chlorination Capital Cost

Estimated UFC Cost

Estimated O&M Cost

Estimated Capital

Cost $132,000.00 $100,000.00 $30,000.00 $232,000.00

Estimated Sodium Hypochlorite Cost

Estimated Cost per m3

Estimated Annual Volume

(m^3)

Estimated Annual

Cost Total

$140 41.975 $5,877.61 $5,877.61 SUMMARY

Distribution Systems

Total Capital Costs Annual Costs

$ 1,127,500.00 $ 1,391,510.00 $ 50,877.61

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SOURCES

1. The USGA, Wastewater Reuse for Golf Course Irrigation, Michigan: Lewis Publishers, 1994.

2. The U.S. Environmental Protection Agency, Guidelines for Wastewater Reuse, Washington D.C: Camp Dresser & McKee Inc., 2004.

3. Asano, Takashi, Wastewater Reclamation and Reuse, Pennsylvania: Technomic Publishing Company Inc., 1998.

4. The State of Michigan, “Who needs and NPDES permit?” The Michigan Department of Environmental Quality. 2008. The State of Michigan. 7 Dec. 2008. http://www.michigan.gov/deq/0,1607,7-135-3313_3682_3713-10200--,00.html

5. O’Conner, Sean. Personal Interview. 2 Oct. 2008.

6. The U.S. Department of Agriculture, Diagnosis and Improvement of Saline and Alkali Soils, Washington, D.C.: U.S. Government Printing Office, 1954

7. Robbins, C. “Sodium adsorption ration-exchangeable sodium percentage relationships in high potassium saline-sodic soil”. Irrigation Sciences 5 (1984).

8. Electric Power Research Institute. “Agricultural use of gypsum and other products from Flue Gas Desulfurization (FGD) systems”. 2006. Electric Power Research Institute. 1 Dec. 2008. http://mydocs.epri.com/docs/public/000000000001014637.pdf

9. Hartley, T.W. “Public perception and participation in water reuse”. Desalination 187 (2006).

10. Downs, A., and C.Adams. The Chemistry of Chlorine,Bromine, Iodine and Astatine. Pergamon, Oxford, 1973.

11. Aieta, E., and P. Roberts. “The Chemistry of Oxo-Chlorine Compounds Relevent to Chlorine Dioxide Generation,” In Water Chlorination: Environmental Impact and Health Effects, vol. 5 (R. Jolley, ed.). Boca Raton, FL: Lewis Publishers, 1985.

12. Morris, J. C. “The Mechanism of the Hydrolysis of Chlorine.” Journal of the American Chemical Society, 68:1692–1694, 1946.

13. Chang, S. “Modern Concept of Disinfection.” ASCE Journal of the Sanitary Engineering Division, 97(689), 1971.

14. Morris, J. “Kinetics of Reactions Between Aqueous Chlorine and Nitrogen Compounds.” In Principles and Applications of Water Chemistry (S. Faust, ed.).Wiley, New York, 1967.

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15. Isaac, R., and J. Morris. “Rates of Transfer of Active Chlorine Between Nitrogenous Substances,” In Water Chlorination: Environmental Impact and Health Effects (R. Jolley, ed.). Butterworth, Stoneham, MA, 1980.

16. Baker, R. “Studies on the Reaction Between Sodium Hypochlorite and Proteins. I. Physicochemical. Study of the Course of the Reaction.” Biochemical Journal, 41:337, 1947.

17. Wright, N.“The Action of Hypochlorites on Amino Acids and Proteins:The Effects of Acidity and Alkalinity.” Biochemical Journal, 30:1661, 1936.

18. Wojtowicz, J. A. “Chlorine Monoxide, Hypochlorous Acid, and Hypochlorites,” In Kirk-Othmer Encyclopedia of Chemical Technology (3d ed.). vol. 5 (R. E. Kirk et al., eds.).Wiley, New York, p. 580–611, 1979.

19. Cachaza, J. “Kinetics of Oxidation of Nitrite by Hypochlorite in Aqueous Basic Solution.” Canadian Journal of Chemistry, 54:3401, 1976.

20. Valentine,R. “Disappearance of Monochloramine in the Presence of Nitrite,” In Water Chlorination:Environmental Impact and Health Effects, vol. 5 (R. Jolley, ed.). Lewis Publishers, Chelsea, MI, 1985.

21. Camberato, J.J. “Overcoming High Sodium in Soil and Irrigation Water”. Clemson University. 1 Dec. 2008.http://virtual.clemson.edu/groups/turfornamental/Irrigation%20Water%20Quality/overcoming_high_sodium.htm

22. The Innovation Group. “Chemical Profiles: Sodium Hypochlorite”. The Innovation Group. 17 Jan. 2003. http://www.the-innovation-group.com/ChemProfiles/Sodium%20Hypochlorite.htm

23. Texas Water Development Board. “Cost Estimating Procedures: TWDB Region H”. Texas Water Development Board. 2006. http://www.twdb.state.tx.us/rwpg/2006_RWP/RegionH/CD-Region%20H%202006%20Plan/Chapter%204/Appendices/Appendix%204C%20-%20Cost%20Estimating%20Procedures/FINAL%20CHAPTER_4C%20Cost%20Estimating%20Procedure.pdf

24. Division of Oil and Public Safety. “Rates for a activities associated with the excavation, transportation and disposal of petroleum-contaminated soils”. Colorado Department of Labor and Employment. 25 Jan. 2005. http://oil.cdle.state.co.us/Archive_Old%20Items/Fund/excvdisp.asp

25. The US Environmental Protection Agency. “Wastewater Technology Factsheet: Chlorine Disinfection”. Sept. 1999.

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26. Snoeyink,V., and M. Suidan.“Dechlorination by Activated Carbons and Other Dechlorinating Agents.” In Disinfection: Water and Wastewater (J. Johnson, ed.). Ann Arbor Science, Ann Arbor, MI, 1975.

27. Watson, H. E. “A Note on the Variation of the Rate of Disinfection with Change in the Concentration of the Disinfectant.” Journal of Hygiene, 8:536–542, 1908.

28. Dennis, W. H. et al. “Mechanism of Disinfection: Incorporation of 36Cl into f2 Virus.” Water Research, 13:363, 1979b.

29. Pentech- Houdaille Industries.

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APPENDIX

Waste Characterization Guidelines

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