Appendix a Settlement and Slope Stability Analyses

Appendix A Settlement and Slope Stability Analyses

SETTLEMENT & SLOPE STABILITY ANALYSES

Saugus RESCO Landfill Saugus, Massachusetts

Prepared for:

June, 2008

Prepared by:

11 Northeastern Boulevard Salem, NH 03079-1953

Project 119504

Table of Contents______

List of Tables ...... ii List of Attachments ...... ii

1.0 Introduction...... 1-1 2.0 General Subsurface Conditions ...... 2-1 3.0 Settlement Analysis ...... 3-1 3.1 General...... 3-1 3.2 Settlement Model...... 3-1 3.3 Calculations...... 3-2 4.0 Static and Seismic Slope Stability Analyses ...... 4-1 4.1 General...... 4-1 4.2 Method of Analyses...... 4-1 4.2.1 Slope Stability Analyses ...... 4-1 4.2.2 Permanent Displacement Analysis for Seismic Conditions ...... 4-2 4.3 Cross-Section Across Phase III...... 4-2 4.3.1 Critical Slope Stability Cross-Section ...... 4-2 4.3.2 Subsurface Conditions for Analysis...... 4-2 4.3.3 Shear Strength of Boston Blue Clay...... 4-3 4.3.4 Results of Slope Stability Analyses ...... 4-4 4.3.4.1 Static Slope Stability Assuming No Consolidation of BBC ...... 4-4 4.3.4.2 Static Slope Stability Assuming Consolidation of BBC...... 4-4 4.3.4.3 Slope Stability under Seismic Conditions...... 4-4 4.4 Cross-Section Across Phase IV...... 4-6 4.4.1 Critical Slope Stability Cross-Section ...... 4-6 4.4.2 Soil Parameters...... 4-6 4.4.3 Results of Static Slope Stability Analysis...... 4-6 4.4.4 Results of Seismic Slope Stability Analysis...... 4-7 5.0 Conclusions and Recommendations...... 5-1 5.1 Settlement ...... 5-1 5.2 Slope Stability...... 5-1 6.0 Bibliography...... 6-1

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List of Tables ______

Table 1 Boston Blue Clay Consolidation Calculations Table 2 Undrained Shear Strength of Boston Blue Clay Under Partial Consolidation Table 3 Undrained Shear Strength of Boston Blue Clay Under 100% Consolidation Table 4 Summary of Slope Stability Analyses Results – Cross Section Across Phase III Table 5 Summary of Slope Stability Analyses Results – Cross Section Across Phase IV

List of Attachments ______

Attachment A Settlement Analysis Attachment B Results of Static and Seismic Slope Stability Analyses Cross-Section Across Phase III B-1 Location of Slope Stability Cross-Section and Test Boring B-2 Results of Static Slope Stability Analysis B-3 Probabilistic Seismic Hazard Based on USGS B-4 Pseudo-Static Slope Stability Analysis to Determine Yield Acceleration B-5 Permanent Displacement Calculations Attachment C Results of Static and Seismic Slope Stability Analyses Cross-Section Across Phase IV C-1 Results of Static Slope Stability Analysis C-2 Results of Seismic Slope Stability Analysis

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1.0 Introduction

Refuse Energy Systems Company (RESCO), now known as Wheelabrator Saugus, J.V. (Wheelabrator), owns and operates a waste-to-energy plant and the adjacent ash residue disposal site, known as the Saugus RESCO Landfill (Landfill), in Saugus, Massachusetts. The Landfill accepts municipal solid waste (MSW) ash residue from the waste-to-energy plant located adjacent to the Landfill. The currently approved final grading plan for the Landfill consists of a ridge and valley configuration with a maximum elevation of 50 feet mean sea level (MSL) along the ridges. In all, there are five valley lines and six ridge lines. In addition, the Landfill consists of five phases, I through V. Phases I and II have been filled to the currently approved final grading, and Phases III, IV, and V are currently uncapped and either active or dormant covered with a layer of intermediated cover.

In accordance with the 2008 Revisions to the Final Engineering Plan (2008 FEP), additional ash residue will be placed within the area between ridges by flattening the cross-slope (this is referred to as the “valley fill”). The minimum cross-slope will be decreased from a five percent to a two percent slope, with a side slope of three horizontal to one vertical immediately adjacent to the valley line and in the perimeter areas. The slope along the length of the valley line will be maintained at one percent. The maximum Landfill elevation will remain at 50 feet MSL.

This report presents the results of analyses performed by Shaw Environmental, Inc. (Shaw) to determine the impact of the valley fill on landfill settlement and global slope stability of the Landfill Phases III, IV, and V.

The settlement analysis was performed using an idealized cross section taken at a critical cross section located within Phases III and IV. The slope stability was analyzed using two cross sections. The first slope stability cross section was taken perpendicular to the western perimeter of Phase III. The second slope stability cross section was taken perpendicular to the northwestern perimeter of Phase IV.

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2.0 General Subsurface Conditions

Boring logs of existing test borings and monitoring wells were used to interpret the general subsurface conditions at the Landfill. No field investigation or laboratory tests were performed as part of this study. A review of these logs shows that the Landfill is underlain by the following strata, starting from the top:

• Existing municipal solid waste (MSW) ash residue

• Municipal solid waste

• A layer of peat (not encountered at all locations)

• A layer of sand

• Boston Blue Clay (BBC)

• Glacial till

In general, ash residue deposits vary from 0 to 40 feet in thickness to a maximum elevation of 50 feet MSL overlying the MSW. The bottom of MSW is at an approximate elevation of 0 feet MSL with a maximum thickness of approximately 25 to 30 feet. The thickness of peat varies from 0 to 7 feet. The thickness of sand is between 5 to 10 feet. The thickness of the BBC varies from 20 to 80 feet. The BBC consists of an over-consolidated upper crust which has a medium stiff consistency. The lower part of the BBC is soft, and it is normally consolidated.

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3.0 Settlement Analysis

3.1 General The purpose of the settlement analysis performed was to determine whether the proposed two percent cross-slope will be adequate to accommodate any differential settlements in the Landfill that may occur in the future. If excessive differential settlement were to occur, surface water runoff to the valleys would be impeded which could result in ponding of surface water. The settlement analysis was performed for an idealized cross-section taken between a critical ridge and valley identified based on the subsurface conditions.

3.2 Settlement Model The MSW ash residue is relatively incompressible due to its cementing properties. Similarly, the settlement of the sand layer can be assumed to be very small because it is dense and its thickness is small. Therefore, the only strata that would contribute to landfill settlement include the following: MSW, peat layer, and the BBC. There are two settlement components associated with all of these three strata: (i) primary compression, and (ii) secondary compression. The potential contribution of each of these two components to differential settlement is discussed below.

Primary Compression: The primary compression or primary consolidation of peat and BBC occur when the surcharge load is transferred to the soil skeleton as the excess pore pressure dissipates with time. Although the primary compression mechanism is different for MSW, the state-of-practice is to model its primary compression similar to primary consolidation of peat or clay. The magnitudes of the final value of primary compression of all three strata are proportional to: (i) the thickness of each stratum, and (ii) the magnitude of the surcharge loading. Although the subsurface condition (i.e., thicknesses of the various strata) under the site may vary with location, it is reasonable to assume that such change would be minimal over the length of settlement cross-section taken between any adjacent ridges and valleys because of the relatively short length. Therefore, it can be assumed that the change in subsurface conditions would have very little impact on differential settlement between adjacent ridges and valleys. Accordingly, only the differential settlement due to change in surcharge loading between two points is considered. Also, since the final value of the primary compression (i.e., at 100 percent consolidation) is of interest, the time rate of settlement is not of importance.

Secondary Compression: Secondary compression within peat and BBC occur due to an internal rearrangement of the soil skeleton with time, which is independent of surcharge loading. This is a time dependent phenomenon. The secondary compression of MSW occurs due to biological decomposition of the waste with time. Again, the state-of-practice is to model the secondary

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compression of MSW similar to the secondary consolidation of peat or clay. Also, only the final value of the secondary compression for all three strata is of interest. Since it is not dependent on surcharge loading, the secondary compression can contribute to differential settlement between two adjacent points only if the strata thicknesses between the two points vary. Since it is assumed that the thicknesses of strata are relatively uniform between adjacent ridges and valleys, the contribution of secondary compression to differential settlement should be negligible. It should also be noted that since the MSW is relatively old, it is very likely that almost all of the secondary settlement has already taken place. Accordingly, contribution of differential settlement due to secondary compression has been discounted in the settlement analysis.

Based on the above discussion, it can be seen that only the primary compressions of MSW, peat, and BBC due to the difference in surcharge loading between two points need to be computed to estimate the differential settlement between those two points. The critical settlement points are selected along a cross-section taken perpendicular to the critical ridge and valley.

3.3 Calculations The settlement analysis is presented in Attachment A. Based on a review of the existing test boring logs, Shaw developed a typical cross-section along with an idealized subsurface profile. The calculations estimated a slope reduction of approximately 0.24 percent (i.e., post-settlement slope of 1.76 percent) between the critical ridge and valley. A long-term post-settlement slope of 1.76 percent would be adequate to promote surface run-off.

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4.0 Static and Seismic Slope Stability Analyses

4.1 General In accordance with the 2008 FEP, ash residue placement will continue in Phases III, IV, and V. To analyzed the global slope stability of Phases III, IV, and V, the following two cross sections were used:

• The first cross section is perpendicular to the western perimeter of Phase III where the thickness of the underlying BBC is inferred to be the greatest within Phases III, IV, and IV. This is referred to as Cross Section Across Phase III in this report. At this location, a significant thickness of MSW and ash residue is already present; therefore, consolidation of the BBC from the existing surcharge loading was considered in the slope stability analysis of this cross section.

• The second cross section is perpendicular to the northwestern perimeter of Phase IV. This is referred to as Cross Section Across Phase IV in this report. At this location, the thickness of the BBC is relatively small. However, the thickness of the existing ash residue is minimal; therefore, the slope stability analysis for this cross section was performed assuming no consolidation of the BBC. Also, the slurry wall at this location is closest to the toe of the Landfill slope; therefore, sliding block type failure surfaces through the slurry wall were analyzed at this cross section location to determine the potential impact of the Landfill slope on the slurry wall. 4.2 Method of Analyses 4.2.1 Slope Stability Analyses The slope stability analysis for the Landfill was performed using the computer program GSTABL7© (Version 2.0) developed by Gregory Geotechnical Software (GGS 2001) in conjunction with the user interface program STEDwin© (Version 3.56) developed by Annapolis Engineering Software. The GSTABL7© computer program is an advanced version of the original STABL computer program developed at Purdue University (Purdue 1988). GSTABL7© performs two-dimensional limit equilibrium analysis using the method of slices to compute factors of safety against slope instability based on any of the following four analysis procedures:

• The modified Bishop method for circular failure surfaces (this method satisfies only moment equilibrium)

• The simplified Janbu method for circular, random, or sliding block failure surfaces (this method satisfies only force equilibrium)

• The Spencer method for circular, random, or sliding block failure surfaces (this method satisfies both force and moment equilibrium)

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• The Morgenstern-Price method for circular, random, or sliding block failure surfaces (this method also satisfies both force and moment equilibrium)

Because they satisfy both force and moment equilibrium, the factors of safety computed from the Spencer and the Morgenstern-Price methods are more accurate than those obtained from the other two methods. However, the factors of safety computed from the modified Bishop method for circular failure surfaces are typically very close to those computed from Spencer or Morgenstern-Price methods. The simplified Janbu method typically yields conservative factors of safety.

The slope stability analyses presented in this report were performed using the modified Bishop method for circular failure surfaces. To be conservative, the simplified Janbu method with the active and passive wedges generated according to the Rankine theory were used for sliding-block failure surfaces.

4.2.2 Permanent Displacement Analysis for Seismic Conditions The likely magnitude of the seismically-induced paramagnet displacement has been estimated using the simplified charts published by Makdisi and Seed (1978). These charts make use of the

ratio of the yield acceleration to the maximum horizontal acceleration (ky/kmax) to provide an estimate of the likely permanent displacement. The yield acceleration value is the horizontal acceleration that results in a pseudo-static factor of safety of 1. The yield acceleration was determined using pseudo-static slope stability analysis using GSTABL©. The maximum acceleration is the maximum of the acceleration values averaged over the entire failure surface.

4.3 Cross-Section Across Phase III 4.3.1 Critical Slope Stability Cross-Section As noted previously, based on a review of the existing subsurface information in conjunction with the existing and designed ash residue grading at the landfill, a cross-section perpendicular to the western perimeter of Phase III is the most critical for slope stability of the three remaining phases. The location of this critical cross-section is shown in Attachment B-1. The design slope of the ash residue along the landfill perimeter is 3H:1V from elevation 20 feet to elevation 50 feet MSL at this cross-section.

4.3.2 Subsurface Conditions for Analysis The subsurface conditions at this cross-section location have been determined based on existing test boring logs (Wehran 1989; The IT Group 2000). Test boring PTB-8, monitoring well PMW- 5D, and piezometer PZ-00-4 are located in the vicinity of the selected critical slope stability cross-section; boring logs for these locations are used to approximate the subsurface conditions under the selected slope stability cross section. Based on these logs (see Attachment B-1) and literature from the 1976 MIT test site along I-95 in Saugus, the following thicknesses have been

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assumed for the various layers/strata underlying the existing ash residue (listed in a descending order):

− Existing MSW = 20 feet − Peat = 7 feet − Sand/Silt = 5 feet − Medium Boston blue clay = 18 feet − Soft Boston blue clay = 60 feet − A till or bedrock was assumed below El. –90 (NGVD)

4.3.3 Shear Strength of Boston Blue Clay

A short-term analysis for the end-of-filling stage using undrained shear strengths (Su) for the BBC represents the most critical slope stability condition. Therefore, the most critical soil parameter for slope stability is the undrained shear strength of the BBC. To our knowledge, no site-specific shear strength testing of the BBC is available for the Landfill. Therefore, Shaw has used the soil testing information from the Massachusetts Institute of Technology (MIT) research work performed in 1976 for the I-95 embankment in Saugus. This information was provided to Wehran Engineering (now Shaw) by Prof. Charles Ladd of MIT in 1988. A method developed by Ladd and Foott (1974), known as SHANSEP (stress history and normalized soil engineering properties), was used to estimate the undrained shear strength of the BBC with depth.

Because of the presence of sandy strata both above and below the BBC stratum, it is assumed that the BBC has two-way drainage. Since the Su of the BBC varies with depth, the BBC was

subdivided into vertical layers to assign varying Su values with depth. To account for the varying surcharge loading from the varying ash residue height across the cross section, the BBC was also subdivided horizontally.

It should be noted that the BBC has been gaining shear strength with time due to its consolidation from the weight of the MSW and the ash residue. To simplify shear strength gain computations, the consolidation due to the MSW and the ash residue have been computed separately and added (i.e., a linear superposition was used). The shear gain due to the MSW has been computed through 2008 assuming that the MSW was placed linearly between 1955 and 1985. The degree of consolidation calculations in Table 1 show that the BBC is almost fully consolidated under the weight of the MSW placed prior to 1985. The shear strength gain due to weight of the ash residue has been computed assuming that the ash residue was placed linearly between 1985 and 2008. The calculations presented in Table 1 show that the consolidation of the BBC varies with depth from 59 to 83 percent.

The shear strength calculations are shown in Table 2. This table also shows the SHANSEP equation and parameters used to estimate the Su. The left part of Table 2 shows the estimated

original Su of the BBC corresponding to pre-landfill conditions assuming the original ground

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elevation to be at 0 feet MSL. The estimated Su values in Table 2 have been used in the static slope stability analysis.

Table 3 shows the Su values assuming full consolidation of the BBC under both the MSW and the ash residue. These Su values have been used in the seismic slope stability analysis.

4.3.4 Results of Slope Stability Analyses 4.3.4.1 Static Slope Stability Assuming No Consolidation of BBC The initial slope stability analysis was performed using the original shear strength of the BBC corresponding to the original ground elevation (assumed to be 0 feet MSL) prior to any waste placement at the Landfill. Therefore, this analysis ignores the consolidation and resulting strength gain within the BBC from the waste/ash residue placement above elevation 0 feet MSL.

As noted previously, the computed Su values for the BBC are shown in Table 2. The slope stability analysis using these original Su values for the BBC yielded a minimum factor of safety of 1.36, which less than the acceptable factor of safety of 1.5. This shows that consolidation of the BBC should be considered in the slope stability analysis. The slope stability analysis results are included in Attachment B-2.

4.3.4.2 Static Slope Stability Assuming Consolidation of BBC This slope stability analysis accounts for the likely shear strength gain within the BBC from the weight of the MSW and ash residue. The shear strength gain calculations are discussed in

Section 4.3; the estimated Su values corresponding to this condition are shown in Table 3. The static slope stability analysis assuming consolidation of the BBC through 2008 yielded a minimum factor of safety 1.6, which is greater than the acceptable value of 1.5. The slope stability analysis results are included in Attachment B-2.

4.3.4.3 Slope Stability under Seismic Conditions General

Subtitle D regulations require that landfills located within seismic impact zones1 be designed to withstand peak ground acceleration (PGA) value having a ten percent probability of exceedance in 250 years (which is equivalent to two percent probability of exceedance in 50 years). Based on the United States Geological Survey (USGS) website, the PGA having a two percent probability of exceedance in 50 years for this site is determined to be 0.16g; the corresponding moment magnitude of the earthquake is 6. Printouts of the USGS based probabilistic seismic hazard are included in Attachment B-3. Since the PGA value is greater than 0.1g, this Landfill is located within a seismic impact zone and, therefore, requires a seismic slope stability analysis.

1 Seismic impact zones are areas where the peak ground acceleration having a 10 percent probability of exceedance 250 years is greater than 0.10g.

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Because the seismic loading is cyclic in nature (i.e., loading magnitude and direction change rapidly with time), an allowable factor of safety criterion is not appropriate for seismic slope stability. Instead, the state-of-practice is to use the concept of an acceptable permanent displacement. According to the U.S. Environmental Protection Agency (USEPA 1995), 12 inches is considered as the maximum allowable limit of seismically-induced permanent displacement for landfill slopes.

Based on Newmark (1965), the potential for permanent displacement exists only if the maximum of the average horizontal accelerations induced within the slope stability cross-section exceeds the yield acceleration. The yield acceleration is the horizontal acceleration that results in a pseudo-static factor of safety of 1, which corresponds to an incipient state of slope movement. Therefore, the first step in the seismic slope stability analysis is to determine the yield acceleration value for the cross-section analyzed.

Yield Acceleration

An iterative pseudo-static slope stability analysis was performed using the GSTABL7© computer program to determine the minimum yield acceleration for the critical slope stability cross section analyzed. The iterative analysis involved repeating the pseudo-static slope stability analysis by varying the input horizontal acceleration value until the resulting factor of safety is 1.

The PGA value corresponding to a ten percent probability on 250 years has a recurrence interval of 2,475 years. Therefore, it is reasonable to assume that the BBC has gained 100 percent

consolidation when the site is subjected to the design PGA value. Accordingly, the Su values from Table 3 that correspond to 100 percent consolidation under the MSW and ash residue were assigned to the BBC while determining the yield acceleration. The iterative analysis showed that the minimum yield acceleration value for the critical cross section analyzed is 0.081g. The results of the final iterations of the pseudo-static slope stability analyses are included in Attachment B-4.

Since the computed yield acceleration value is less the PGA value (i.e., 0.16g), a permanent displacement analysis was performed as discussed below.

Permanent Displacement

In the absence of seismic response analysis (e.g., SHAKE) to determine the time history of average accelerations within the critical failure surface, it is assumed that the maximum of the

average acceleration values (kmax) within the critical failure surface (corresponding to the yield acceleration value) is equal to the PGA value. This assumption is conservative since the magnitudes of horizontal acceleration values at different points within the failure plane would be different, and all of these values would be less than or equal to the PGA value; therefore, the

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average accelerations at different time durations (and hence the kmax) would be typically less than the PGA value.

The permanent displacement calculations performed using the Makdisi and Seed (1978) chart is presented in Attachment B-5. These calculations estimate a maximum permanent displacement of approximately 4 inches. Since this is less than the maximum allowable limit of 12 inches, it is acceptable.

The results of both static and seismic slope stability analyses for this cross-section are summarized in Table 4.

4.4 Cross-Section Across Phase IV 4.4.1 Critical Slope Stability Cross-Section Since the existing ash residue elevations within Phase IV are significantly lower than 50 feet, it is concluded that slope stability along the outer perimeter of Phase IV could be critical, at this stage of the landfill operation. Accordingly, this second cross-section taken perpendicular to the northwestern perimeter of Phase IV (next to Route 107) was analyzed for slope stability. The location of this cross-section is shown in Attachment C-1. The subsurface condition at this cross-section location was interpreted based on the log for test boring PTB-6 (the boring log is included in Attachment C-1).

4.4.2 Soil Parameters Again, a short-term analysis for the end-of-filling stage using undrained shear strength for the BBC represents the most critical slope stability condition. Therefore, as noted previously, the critical soil parameter for slope stability is the undrained shear strength of the soft BBC. The shear strength calculations along with the SHANSEP parameters used are presented in Attachment C-1. The initial average undrained shear strength of the BBC at the analyzed cross-section location, assuming no consolidation, is conservatively estimated to be 1,015 pounds per square foot (psf).

4.4.3 Results of Static Slope Stability Analysis Slope stability of the Landfill slope with both circular and sliding-block type failure surfaces was analyzed. The sliding-block type failure surface was also used to analyze potential failure surfaces that pass through the slurry wall.

As noted previously, a short-term analysis using undrained shear strength for the BBC represents the most critical slope stability condition. To be conservative2, this analysis was performed

2 It should be noted that the shear strength of the BBC will increase with time due consolidation from the ash to be placed in the future. Therefore, the analyses performed are conservative.

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assuming the current undrained shear strength for the BBC which is estimated to be 1015 psf. This analysis yielded a static factor of safety of 2.15 for the circular failure mode and 1.87 for the sliding-block type failure mode. A sliding-block failure surface passing through the slurry wall yielded a higher factor of safety of 2.06. Therefore, all the computed factors of safety values are greater than the acceptable value of 1.5.

The results of slope stability analyses for static conditions are included in Attachment C-1. A summary of the results is presented in Table 5.

4.4.4 Results of Seismic Slope Stability Analysis The yield acceleration was determined using the GSTABL7© computer program. Again, the estimated original undrained shear strength was assigned to the BBC in this analysis, which is conservative because it ignores consolidation and strength gain within the BBC. The analysis shows a minimum yield acceleration value of 0.151g for a sliding-block type failure mode through the slurry wall. Since this value is very close to the PGA, the anticipated permanent displacement would be very small. A permanent displacement analysis using the Makdisi and Seed (1978) chart estimated a permanent displacement of only 0.1 inches, which is significantly lower than the allowable limit of 12 inches.

The GSTAB7© plots and printouts of the pseudo-static slope stability analyses are included in Attachment C-2. The permanent displacement analysis is also presented in Attachment C-2. A summary of the computed yield acceleration values and the estimated permanent displacement is shown in Table 5. It should be noted that these results are conservative because: (i) they ignore the consolidation of the BBC during filling, and (ii) the slope stability analyses were performed using the Janbu method.

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5.0 Conclusions and Recommendations

5.1 Settlement The settlement analysis discussed herein demonstrates that a minimum slope of two percent over the valley fill areas of the Landfill would be adequate to accommodate future differential settlements.

The settlement analysis is a predictive assessment of the anticipated settlement based on idealized subsurface conditions and assumed settlement model and parameters. It is possible that actual subsurface conditions may not be as uniform as inferred from the limited test borings and settlement parameters could vary, which could result in a few localized depressions. Therefore, provisions are included in the Closure and Post-Closure Plan for the Landfill for inspection and re-grading of the final cover if detrimental differential settlements are observed in the field.

5.2 Slope Stability

The slope stability analysis for the Landfill shows adequate factors of safety under static conditions for both circular and sliding-block type failure surfaces, including failure surfaces through the slurry wall. The seismic analysis shows that the potential for excessive permanent displacement during the design earthquake does not exist.

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6.0 Bibliography

Bray, J.D., Rathje, E.M., Augello, A.J., and Merry, S.M. (1998). "Simplified Seismic Design Procedure for Geosynthetic-Lined, Solid-Waste Landfills." Geosynthetics International, Vol. 5, Nos. 1-2.

Code of Federal Regulations, Title 40, Part 258.

Gregory Geotechnical Software (GGS). (2001). GSTABL7© with STEDwin© Slope Stability Analysis System, Program Manual, Version 2.0, dated September 2001.

Kavazanjian, Jr., E., Matasovic, N., Bonaparte, R., and Schmertmann, G.R. (1996). "Evaluation of MSW Properties for Seismic Analysis." Geoenvironment 2000, Geotechnical Special Publication No. 46, pp. 1126-1141.

Ladd, C.C. and Foott, R. (1974). “New Design Procedures for Stability of Soft Clays,” Journal of the Geotechnical Engineering Division, Proceedings of the American Society of Civil Engineers, Vol. 100, GT 7, July, pp. 763-786.

Makdisi, F.I., and H.B. Seed. (1978). “Simplified Procedure for Estimating Dam and Embankment Earthquake-Induced Deformations." Journal of the Geotechnical Engineering Division, ASCE, Vol. 104, No. GT7.

Newmark, N.M. (1965). "Effects of Earthquakes on Dams and Embankments." Geotechnique, Volume 5, No. 2.

Purdue University. (1988). User Guide for PC STABL 5M.

Schiffman R.L. (1958). "Field Applications of Soil Consolidation: Time-Dependent Loading and Varying Permeability,” Highway Research Board, Bulletin 248.

U.S. Environmental Protection Agency (EPA). (1995). RCRA Subtitle D (258) Seismic Design Guidance for Municipal Solid Waste Landfill Facilities by Gregory N. Richardson, Edward Kavazanjian, Jr., and Neven Matasovic, Report No. EPA 600/R-95/051.

USGS website: http://earthquake.usgs.gov/research/hazmaps/

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Tables

Table 1 Boston Blue Clay Consolidation Calculations Cross Section Across Phase III Saugus RESCO Landfill

1. Consolidation from Existing MSW Based on ash residue filling at 3H:1V to elevation 50 feet MSL Approximate year the MSW filling started = 1955 Approximate year MSW filling ended = 1985

Assuming the waste filling took place linearly t0 = 30 years Year when percent of consolidation required 2008 t = 53 years

Based on the 1999 analysis, Cv for the clay cv = 0.2 ft2/day Total thickness of clay 2H = 78 ft2/day Assuming two-way drainage H = 39 ft

2 T0 = Cv . t0/H T0 = 1.44 2 T = Cv . t/H T = 2.54

T-T0 = 1.10

Soil Nos. z z/H up/u0(T) up/u0(T-T0)T0.u/u0 u/u0 % Consol. (see Note 1) (See Note 2) (See Note 2) 5, 6, 7, 8, & 9 9 0.23 0.001 0.015 0.014 0.01 99 10, 11, 12, 13, &14 33 0.85 0.0032 0.04 0.0368 0.03 97 15, 16, 17, 18, & 19 15 0.38 0.002 0.025 0.023 0.02 98

Notes: 1. Soil nos. correspond the soil numbering used in the slope stability analysis 2. These value are obtained from Table 2 of "Field Applications of Soil Consolidation: Time-Dependent Loading and Varying Permeability", by Schiffman, R.L. (1958). z = depth u = excess pore pressure

2. Consolidation from Ash Residue Based on ash residue filling at 3H:1V to elevation 50 feet MSL Approximate year the ash filling started = 1985 Year when percent consolidation required = 2008

Assuming the filling to be linear t0 = t = 23 2 T =T0 = Cv . t0/H T0 = T = 1.10

2 uz/u0 = (z/H) - (0.5)(z/H)

Soil Nos. z z/H uz/u0 up/u0(T) T0.u/u0 u/u0 % Consol. (See Note) 5, 6, 7, 8, & 9 9 0.23 0.204 0.015 0.189 0.17 83 10, 11, 12, 13, &14 33 0.85 0.488 0.04 0.448 0.41 59 15, 16, 17, 18, & 19 15 0.38 0.311 0.025 0.286 0.26 74

Note: These value are obtained from Table 2 of "Field Applications of Soil Consolidation: Time-Dependent Loading and Varying Permeability", by Schiffman, R.L. (1958). Table 2 Undrained Shear Strength of Boston Blue Clay Under Partial Consolidation Cross Section Across Phase III Saugus RESCO Landfill

Based on ash residue filling at 3H:1V to elevation 50 feet MSL Original ground elevation = 0.0 ft Total unit weight of clay = 108.0 pcf Ground water elevation = 0.0 ft Unit weight of water = 62.4 pcf Unit weight of MSW = 65.0 pcf Unit weight of ash = 100.0 pcf

σ'vc Consolidation from MSW Consolidation from Ash ∆σ'vc σ'vc + ∆σ'vc

Soil No. Soil Elev. Effect. OCR Original Su MSW Ht. MSW Wt. % Consol. Stress Incr. Ash Ht. Ash Wt. % Consol. Stress Incr. Total Stress New Effect. New OCR New Su Stress (see Note 1) (see Note 2) Increase Stress (see Note 3) (ft) (psf) (psf) (ft) (psf) (psf) (ft) (psf) (psf) (psf) (psf) (psf) 1 Ash 2 MSW 3 Peat 1000 4 Silt/Sand 5 Med. BBC -21.0 957.6 5 656 12.5 813 99 804 0 0 83 0 804 1762 2.72 757 6 Med. BBC -21.0 957.6 5 656 17.5 1138 99 1126 0 0 83 0 1126 2084 2.30 788 7 Med. BBC -21.0 957.6 5 656 20.0 1300 99 1287 10 1000 83 830 2117 3075 1.56 863 8 Med. BBC -21.0 957.6 5 656 20.0 1300 99 1287 23 2300 83 1909 3196 4154 1.15 926 9 Med. BBC -21.0 957.6 5 656 20.0 1300 99 1287 30 3000 83 2490 3777 4735 1.01 955 10 Soft BBC -45.0 2052 2.5 827 12.5 813 97 788 0 0 59 0 788 2840 1.81 893 11 Soft BBC -45.0 2052 2.5 827 17.5 1138 97 1103 0 0 59 0 1103 3155 1.63 915 12 Soft BBC -45.0 2052 2.5 827 20.0 1300 97 1261 10 1000 59 590 1851 3903 1.31 962 13 Soft BBC -45.0 2052 2.5 827 20.0 1300 97 1261 23 2300 59 1357 2618 4670 1.10 1004 14 Soft BBC -45.0 2052 2.5 827 20.0 1300 97 1261 30 3000 59 1770 3031 5083 1.01 1024 15 Soft BBC -75.0 3420 1.3 836 12.5 813 98 796 0 0 74 0 796 4216 1.05 878 16 Soft BBC -75.0 3420 1.3 836 17.5 1138 98 1115 0 0 74 0 1115 4535 1.00 907 17 Soft BBC -75.0 3420 1.3 836 20.0 1300 98 1274 10 1000 74 740 2014 5434 1.00 1087 18 Soft BBC -75.0 3420 1.3 836 20.0 1300 98 1274 23 2300 74 1702 2976 6396 1.00 1279 19 Soft BBC -75.0 3420 1.3 836 20.0 1300 98 1274 30 3000 74 2220 3494 6914 1.00 1383

Notes: 1. Over-consolidation ratio (OCR) based on MIT data from Route I-95 test fill S = (0.2)(σ ′ )(OCR) 0.765 2. The undrained shear strength (Su) values for BBC were obtained using the following SHANSEP relationship: u σ vc 0.765 3. The undrained shear strength (Su) values were obtained using the following SHANSEP relationship: Su = (0.2)(′vc+∆′σ vc )(OCR) Table 3 Undrained Shear Strength of Boston Blue Clay Under 100% Consolidation Cross Section Across Phase III Saugus RESCO Landfill

σ'vc Consolidation from MSW Consolidation from Ash ∆σ'vc σ'vc + ∆σ'vc

Soil No. Soil Elev. Effect. OCR Original Su MSW Ht. MSW Wt. % Consol. Stress Incr. Ash Ht. Ash Wt. % Consol. Stress Incr. Total Stress New Effect. New OCR New Su Stress (see Note 1) (see Note 2) Increase Stress (see Note 3) (ft) (psf) (psf) (ft) (psf) (psf) (ft) (psf) (psf) (psf) (psf) (psf) 1 Ash 2 MSW 3 Peat 1000 4 Silt/Sand 5 Med. BBC -21.0 957.6 5 656 12.5 813 100 813 0 0 100 0 813 1770 2.70 758 6 Med. BBC -21.0 957.6 5 656 17.5 1138 100 1138 0 0 100 0 1138 2095 2.29 789 7 Med. BBC -21.0 957.6 5 656 20.0 1300 100 1300 10 1000 100 1000 2300 3258 1.47 875 8 Med. BBC -21.0 957.6 5 656 20.0 1300 100 1300 23 2300 100 2300 3600 4558 1.05 947 9 Med. BBC -21.0 957.6 5 656 20.0 1300 100 1300 30 3000 100 3000 4300 5258 1.00 1052 10 Soft BBC -45.0 2052 2.5 827 12.5 813 100 813 0 0 100 0 813 2865 1.79 895 11 Soft BBC -45.0 2052 2.5 827 17.5 1138 100 1138 0 0 100 0 1138 3190 1.61 918 12 Soft BBC -45.0 2052 2.5 827 20.0 1300 100 1300 10 1000 100 1000 2300 4352 1.18 987 13 Soft BBC -45.0 2052 2.5 827 20.0 1300 100 1300 23 2300 100 2300 3600 5652 1.00 1130 14 Soft BBC -45.0 2052 2.5 827 20.0 1300 100 1300 30 3000 100 3000 4300 6352 1.00 1270 15 Soft BBC -75.0 3420 1.3 836 12.5 813 100 813 0 0 100 0 813 4233 1.05 879 16 Soft BBC -75.0 3420 1.3 836 17.5 1138 100 1138 0 0 100 0 1138 4558 1.00 912 17 Soft BBC -75.0 3420 1.3 836 20.0 1300 100 1300 10 1000 100 1000 2300 5720 1.00 1144 18 Soft BBC -75.0 3420 1.3 836 20.0 1300 100 1300 23 2300 100 2300 3600 7020 1.00 1404 19 Soft BBC -75.0 3420 1.3 836 20.0 1300 100 1300 30 3000 100 3000 4300 7720 1.00 1544

Notes: 1. Over-consolidation ratio (OCR) based on MIT data from Route I-95 test fill ′ 0.765 2. The undrained shear strength (Su) values for BBC were obtained using the following SHANSEP relationship: Su = σ(0.2)(σ vc )(OCR) 0.765 3. The undrained shear strength (Su) values were obtained using the following SHANSEP relationship: Su = (0.2)(′vc+∆′σ vc )(OCR)

Table 4 Summary of Slope Stability Analyses Results – Cross Section Across Phase III Saugus RESCO Landfill

Static Estimated Consolidation Yield Analysis S Values from Factor of Permanent of BBC u Acceleration Safety Displacement Static None From Table 2 1.36 -- -- Partial Static From Table 2 1.60(1) -- -- (see Table 1) Yield 100% From Table 3 -- 0.081g 4 inches(1) Acceleration

Notes: BBC = Boston Blue Clay Su = Undrained shear strength (1) These values are acceptable

Table 5 Summary of Slope Stability Analyses Results – Cross Section Across Phase IV Saugus RESCO Landfill

Static Estimated Slope Stability Consolidation Yield Failure Mode Factor of Permanent Run of BBC Acceleration Safety Displacement 1 None Circular 2.15(1) 0.201g --

2 None Block 1.87(1) 0.154g -- Block through 3 None 2.06(1) 0.151g 0.1 inches(1) slurry wall

Notes: BBC = Boston Blue Clay (1) These values are acceptable

Attachment A Settlement Analysis

N:\projects\119504\2008\VF FEP Docs\Global Stability 376' 376' 325' 51'

Elevation 50 A 2% B 6.5 2% 3 3 23.5' 1 1

C Ash 33

Solid Waste 17

0 -0.5 Peat 0.5 -1 Sand/Silt 0.5

Medium Boston Blue Clay 9

-10

20 Soft Boston Blue Clay

-30

Figure 1. Idealized Settlement Cross-Section (Not to Scale)

Page 1 of 5 Required: Determine whether the 2% slope on the final grading will be adequate considering settlement over the long-term

Assumptions: - Figure 1 shows an idealized cross-section taken perpendicular to the valley line - The post-settlement slope between Points A and B would be the most critical - The differential settlement between points A and B will determine the post-settlement slope - Assuming the ash and sand to be relatively incompressible, the underlying layers that will undergo settlement are the solid waste, peat, and Boston Blue Clay (BBC) - All three compressible layers have two components of settlement: (i) a primary compression, which is both load and thickness dependent, and (ii) a secondary compression, which is time and thickness dependent (for waste, the secondary compression includes decomposition of waste with time and for BBC it is secondary consolidation) - To simplify the settlement calculations, it is assumed that the thicknesses of the different compressible strata are uniform; therefore, the secondary settlements at both A and B would be the same - Therefore, only the primary compression due to difference in the surcharge loading between A and B would lead to differential settlement - The difference in surcharge loading between A and B is that due to 6.5 feet of ash - Based on the discussion above, only the primary compression of solid waste, peat, and BBC at Point A due to the 6.5 feet difference in ash thickness needs to be computed to determine the slope change between A and B due to differential settlement

Page 2 of 5 Design Parameters

Critical Slope Length: - Distance between Points A and B = 325 ft - Minimum initial slope = 2 %

Thicknesses of Various Layers: - Thickness of excess ash at Point A = 6.5 ft - Ash thickness at B = 26.5 ft - Thickness of solid waste = 17 ft - Thickness of peat = 0.5 ft - Thickness of sand/silt = 0.5 ft - Thickness of medium Boston Blue Clay = 9 ft - Thickness of soft Boston Blue Clay = 20 ft

Groundwater Table: - Assumed depth to groundwater table = 0 ft

Ash Parameters: - Unit weight = 105 pcf

Solid Waste Parameters: - Unit weight = 65 pcf - Compression ratio = 0.3 - Number of sublayers used = 3

Peat Parameters: - Unit weight = 100 pcf - Compression ratio = 0.4 - Number of sublayers used = 1

Sand/Silt Parameters: - Unit weight = 120 pcf

Medium Boston Blue Clay Parameters: - Unit weight = 110 pcf - Compression ratio = 0.15 - Recompression ratio = 0.02 - Number of sublayers used = 5

Soft Boston Blue Clay Parameters: - Unit weight = 110 pcf - Compression ratio = 0.3 - Recompression ratio = 0.025 - Number of sublayers used = 5

Page 3 of 5 Calculations

Excess Loading at Point A relative to Point B = 682.5 psf

Excess settlement of solid waste under Point A:

Sublayer Sublayer Mid-Depth Total Effective Incremental thickness Elevation Vert. Stress Vert Stress Settlement (ft) (ft) (psf) (psf) inches 1 5.7 14.2 2967 2967 1.83 2 5.7 8.5 3335 3335 1.65 3 5.7 2.8 3703 3703 1.50 Cumulative = 5.0 Inches

Excess settlement of peat under Point A:

Sublayer Sublayer Mid-Depth Total Effective Incremental thickness Elevation Vert. Stress Vert Stress Settlement (ft) (ft) (psf) (psf) inches 1 0.5 -0.25 3912.5 3896.9 0.17 Cumulative = 0.2 Inches

Excess settlement of Medium Boston Blue Clay under Point A:

Sublayer Sublayer Mid-Depth Total Effective Past Max. Final Effective Incremental thickness Elevation Vert. Stress Vert. Stress Vert. Stress Vert. Stress Settlement (ft) (ft) (psf) (psf) (psf) (psf) inches 1 1.8 -1.9 4097 3978 7000 4660 0.03 2 1.8 -3.7 4295 4064 6500 4746 0.03 3 1.8 -5.5 4493 4149 6000 4832 0.03 4 1.8 -7.3 4691 4235 5500 4917 0.03 5 1.8 -9.1 4889 4321 5000 5003 0.03 Cumulative = 0.1 inches

Excess settlement of Soft Boston Blue Clay under Point A:

Sublayer Sublayer Mid-Depth Total Effective Incremental thickness Elevation Vert. Stress Vert. Stress Settlement (ft) (ft) (psf) (psf) inches 1 4.0 -12.0 5208 4459 0.89 2 4.0 -16.0 5648 4649 0.86 3 4.0 -20.0 6088 4840 0.83 4 4.0 -24.0 6528 5030 0.80 5 4.0 -28.0 6968 5220 0.77 Cumulative = 4.1 inches

Differential Settlement between Points A and B = 9.4 inches

Slope reduction between Points A and B due to the above differential settlement = 0.24 %

Post-Settlement Slope = 1.76 %

Page 4 of 5 Page 5 of 5

Attachment B Results of Static and Seismic Slope Stability Analyses Cross-Section Across Phase III

N:\projects\119504\2008\VF FEP Docs\Global Stability

B-1 Location of Slope Stability Cross-Section and Test Boring

N:\projects\119504\2008\VF FEP Docs\Global Stability

B-2 Results of Static Slope Stability Analysis

N:\projects\119504\2008\VF FEP Docs\Global Stability

******************************************************************** SLOPE STABILITY ANALYSIS SYSTEM Modified Bishop, Simplified Janbu, or GLE Method of Slices. (Includes Spencer & Morgenstern-Price Type Analysis) Including Pier/Pile, Reinforcement, Soil Nail, Tieback, Nonlinear Undrained Shear Strength, Curved Phi Envelope, Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Wate Surfaces, Pseudo-Static & Newmark Earthquake, and Applied For ********************************************************************

Analysis Run Date: 2/21/2008 Time of Run: 02:07PM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Global-Stabil\ Output Filename: C:\GEOTECHNICAL\saugus\2008\Global-Stabil\ Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Glob••••tabil\

PROBLEM DESCRIPTION: RESCO; Ash at 3H:1V to El. 50'; No Conso lidation; Run#S1-Bc-1

BOUNDARY COORDINATES 5 Top Boundaries 24 Total Boundaries

Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 160.00 120.00 165.00 2 2 120.00 165.00 150.00 170.00 2 3 150.00 170.00 240.00 200.00 1 4 240.00 200.00 490.00 198.00 1 5 490.00 198.00 600.00 197.00 1 6 150.00 170.00 600.00 170.00 2 7 0.00 150.00 600.00 150.00 3 8 0.00 143.00 600.00 143.00 4 9 0.00 138.00 120.00 138.00 5 10 120.00 138.00 160.00 138.00 6 11 160.00 138.00 200.00 138.00 7 12 200.00 138.00 240.00 138.00 8 13 240.00 138.00 600.00 138.00 9 14 0.00 120.00 120.00 120.00 10 15 120.00 120.00 160.00 120.00 11 16 160.00 120.00 200.00 120.00 12 17 200.00 120.00 240.00 120.00 13 18 240.00 120.00 600.00 120.00 14 19 0.00 90.00 120.00 90.00 15 20 120.00 90.00 160.00 90.00 16 21 160.00 90.00 200.00 90.00 17 22 200.00 90.00 240.00 90.00 18

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 2 of 11 23 240.00 90.00 600.00 90.00 19 24 0.00 60.00 600.00 60.00 20 Default Y-Origin = 0.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) 1

ISOTROPIC SOIL PARAMETERS

20 Type(s) of Soil

Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 105.0 105.0 0.0 38.0 0.00 0.0 1 2 75.0 75.0 0.0 28.0 0.00 0.0 1 3 100.0 100.0 1000.0 0.0 0.00 0.0 1 4 120.0 120.0 0.0 30.0 0.00 0.0 1 5 108.0 108.0 656.0 0.0 0.00 0.0 1 6 108.0 108.0 656.0 0.0 0.00 0.0 1 7 108.0 108.0 656.0 0.0 0.00 0.0 1 8 108.0 108.0 656.0 0.0 0.00 0.0 1 9 108.0 108.0 656.0 0.0 0.00 0.0 1 10 108.0 108.0 827.0 0.0 0.00 0.0 1 11 108.0 108.0 827.0 0.0 0.00 0.0 1 12 108.0 108.0 827.0 0.0 0.00 0.0 1 13 108.0 108.0 827.0 0.0 0.00 0.0 1 14 108.0 108.0 827.0 0.0 0.00 0.0 1 15 108.0 108.0 836.0 0.0 0.00 0.0 1 16 108.0 108.0 836.0 0.0 0.00 0.0 1 17 108.0 108.0 836.0 0.0 0.00 0.0 1 18 108.0 108.0 836.0 0.0 0.00 0.0 1 19 108.0 108.0 836.0 0.0 0.00 0.0 1 20 130.0 130.0 0.0 34.0 0.00 0.0 1 1

1 PIEZOMETRIC SURFACE(S) SPECIFIED

Unit Weight of Water = 62.40 (pcf)

Piezometric Surface No. 1 Specified by 2 Coordinate Points Pore Pressure Inclination Factor = 0.50

Point X-Water Y-Water No. (ft) (ft) 1 0.00 153.00 2 600.00 154.00 1

A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified.

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 3 of 11 3600 Trial Surfaces Have Been Generated.

60 Surface(s) Initiate(s) From Each Of 60 Points Equally Spaced Along The Ground Surface Between X = 0.00(ft) and X = 150.00(ft)

Each Surface Terminates Between X = 200.00(ft) and X = 400.00(ft)

Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = 0.00(ft)

15.00(ft) Line Segments Define Each Trial Failure Surface.

Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First.

* * Safety Factors Are Calculated By The Modified Bishop Method * *

Total Number of Trial Surfaces Evaluated = 3600 Statistical Data On All Valid FS Values: FS Max = 6.927 FS Min = 1.356 FS Ave = 2.362 Standard Deviation = 0.808 Coefficient of Variation = 34.2

Failure Surface Specified By 31 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 10.61 149.39 3 21.85 139.47 4 33.69 130.25 5 46.07 121.79 6 58.96 114.11 7 72.30 107.25 8 86.03 101.23 9 100.12 96.06 10 114.50 91.78 11 129.11 88.41 12 143.91 85.94 13 158.83 84.39 14 173.81 83.77 15 188.81 84.09 16 203.76 85.33 17 218.60 87.49 18 233.28 90.57 19 247.74 94.56 20 261.93 99.43 21 275.79 105.17 22 289.26 111.76 23 302.30 119.17 24 314.86 127.38 25 326.88 136.35

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 4 of 11 26 338.32 146.05 27 349.15 156.43 28 359.30 167.47 29 368.76 179.12 30 377.47 191.33 31 382.17 198.86 Circle Center At X = 176.28 ; Y = 325.69 ; and Radius = 241.93

Factor of Safety *** 1.356 ***

Individual data on the 48 slices

Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 7.0 1907.8 0.0 0.0 0. 0. 0.0 0.0 2 3.0 1998.7 0.0 400.9 0. 0. 0.0 0.0 3 0.6 492.6 0.0 177.6 0. 0. 0.0 0.0 4 7.2 8506.3 0.0 4114.9 0. 0. 0.0 0.0 5 4.0 6901.8 0.0 3932.4 0. 0. 0.0 0.0 6 1.9 3828.0 0.0 2129.5 0. 0. 0.0 0.0 7 10.0 25465.4 0.0 14893.8 0. 0. 0.0 0.0 8 12.4 42956.9 0.0 25313.7 0. 0. 0.0 0.0 9 3.0 12164.0 0.0 7028.1 0. 0. 0.0 0.0 10 9.9 44268.2 0.0 25858.3 0. 0. 0.0 0.0 11 13.3 69427.0 0.0 39712.3 0. 0. 0.0 0.0 12 13.7 81649.7 0.0 45765.3 0. 0. 0.0 0.0 13 14.1 92831.3 0.0 51021.9 0. 0. 0.0 0.0 14 14.4 102729.5 0.0 55462.2 0. 0. 0.0 0.0 15 5.5 41154.1 0.0 21874.6 0. 0. 0.0 0.0 16 2.2 16815.8 0.0 8925.7 0. 0. 0.0 0.0 17 6.9 53551.7 0.0 28268.6 0. 0. 0.0 0.0 18 14.8 120152.8 0.0 61828.2 0. 0. 0.0 0.0 19 6.1 51308.3 0.0 25854.5 0. 0. 0.0 0.0 20 8.8 76736.0 0.0 37875.0 0. 0. 0.0 0.0 21 1.2 10477.7 0.0 5053.3 0. 0. 0.0 0.0 22 13.8 127317.9 0.0 59712.2 0. 0. 0.0 0.0 23 15.0 146000.0 0.0 64932.1 0. 0. 0.0 0.0 24 11.2 113322.0 0.0 48188.3 0. 0. 0.0 0.0 25 3.8 38789.7 0.0 16040.6 0. 0. 0.0 0.0 26 14.8 156045.9 0.0 62658.5 0. 0. 0.0 0.0 27 12.0 128273.8 0.0 49262.3 0. 0. 0.0 0.0 28 2.7 29488.5 0.0 10964.5 0. 0. 0.0 0.0 29 6.7 72927.4 0.0 26916.2 0. 0. 0.0 0.0 30 7.7 83263.8 0.0 30027.0 0. 0. 0.0 0.0 31 14.2 147061.8 0.0 52820.5 0. 0. 0.0 0.0 32 13.9 135542.0 0.0 47874.3 0. 0. 0.0 0.0 33 13.5 122672.1 0.0 42123.9 0. 0. 0.0 0.0 34 13.0 108712.1 0.0 35591.1 0. 0. 0.0 0.0 35 1.3 9958.9 0.0 3193.2 0. 0. 0.0 0.0 36 11.3 83989.4 0.0 25108.1 0. 0. 0.0 0.0 37 12.0 78686.7 0.0 20282.2 0. 0. 0.0 0.0 38 1.9 11615.3 0.0 2607.2 0. 0. 0.0 0.0 39 5.9 32885.9 0.0 6299.8 0. 0. 0.0 0.0 40 3.6 18399.7 0.0 2658.0 0. 0. 0.0 0.0 41 4.1 19616.0 0.0 1974.7 0. 0. 0.0 0.0 42 3.7 16501.2 0.0 575.4 0. 0. 0.0 0.0 43 3.0 12455.5 0.0 0.0 0. 0. 0.0 0.0 44 10.2 37148.9 0.0 0.0 0. 0. 0.0 0.0

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 5 of 11 45 2.1 6449.4 0.0 0.0 0. 0. 0.0 0.0 46 7.4 18994.4 0.0 0.0 0. 0. 0.0 0.0 47 8.7 12544.5 0.0 0.0 0. 0. 0.0 0.0 48 4.7 1868.5 0.0 0.0 0. 0. 0.0 0.0 Failure Surface Specified By 31 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 5.08 160.21 2 15.71 149.62 3 26.97 139.71 4 38.83 130.53 5 51.23 122.09 6 64.14 114.45 7 77.50 107.62 8 91.25 101.64 9 105.35 96.53 10 119.74 92.30 11 134.37 88.98 12 149.18 86.57 13 164.10 85.09 14 179.09 84.54 15 194.09 84.93 16 209.03 86.25 17 223.86 88.49 18 238.52 91.66 19 252.96 95.73 20 267.12 100.69 21 280.94 106.52 22 294.37 113.20 23 307.36 120.71 24 319.85 129.00 25 331.81 138.06 26 343.18 147.85 27 353.91 158.32 28 363.98 169.44 29 373.33 181.17 30 381.94 193.46 31 385.23 198.84 Circle Center At X = 180.40 ; Y = 325.46 ; and Radius = 240.92

Factor of Safety *** 1.360 ***

1 Failure Surface Specified By 32 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 10.71 149.49 3 22.01 139.64 4 33.89 130.47 5 46.29 122.03 6 59.16 114.33 7 72.47 107.41 8 86.17 101.30 9 100.20 96.00

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 6 of 11 10 114.52 91.55 11 129.09 87.95 12 143.84 85.23 13 158.72 83.38 14 173.69 82.42 15 188.69 82.35 16 203.67 83.17 17 218.57 84.87 18 233.35 87.46 19 247.94 90.91 20 262.31 95.23 21 276.39 100.39 22 290.15 106.38 23 303.52 113.17 24 316.47 120.74 25 328.95 129.07 26 340.91 138.12 27 352.31 147.87 28 363.12 158.27 29 373.28 169.30 30 382.78 180.91 31 391.57 193.06 32 395.20 198.76 Circle Center At X = 182.34 ; Y = 334.99 ; and Radius = 252.72

Factor of Safety *** 1.364 ***

Failure Surface Specified By 29 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 12.71 160.53 2 23.33 149.93 3 34.63 140.07 4 46.58 131.00 5 59.11 122.75 6 72.16 115.37 7 85.69 108.88 8 99.62 103.32 9 113.89 98.70 10 128.44 95.07 11 143.21 92.42 12 158.12 90.77 13 173.10 90.13 14 188.10 90.50 15 203.03 91.88 16 217.84 94.27 17 232.46 97.65 18 246.81 102.00 19 260.84 107.31 20 274.48 113.56 21 287.66 120.71 22 300.34 128.73 23 312.44 137.59 24 323.92 147.25 25 334.72 157.66 26 344.80 168.77 27 354.10 180.53 28 362.60 192.90 29 366.20 198.99

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 7 of 11

Circle Center At X = 175.09 ; Y = 312.56 ; and Radius = 222.44

Factor of Safety *** 1.364 ***

1 Failure Surface Specified By 30 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 12.71 160.53 2 23.33 149.94 3 34.62 140.06 4 46.53 130.94 5 59.00 122.61 6 71.99 115.10 7 85.44 108.46 8 99.29 102.71 9 113.49 97.87 10 127.98 93.97 11 142.68 91.02 12 157.55 89.02 13 172.51 88.00 14 187.51 87.96 15 202.49 88.89 16 217.36 90.79 17 232.09 93.66 18 246.59 97.48 19 260.82 102.23 20 274.71 107.90 21 288.20 114.46 22 301.23 121.88 23 313.76 130.13 24 325.72 139.19 25 337.06 149.00 26 347.75 159.53 27 357.73 170.73 28 366.95 182.55 29 375.39 194.95 30 377.72 198.90 Circle Center At X = 180.65 ; Y = 318.23 ; and Radius = 230.38

Factor of Safety *** 1.366 ***

Failure Surface Specified By 29 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 2.54 160.11 2 13.19 149.54 3 24.53 139.72 4 36.50 130.68 5 49.05 122.47

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 8 of 11 6 62.12 115.11 7 75.66 108.66 8 89.61 103.13 9 103.89 98.55 10 118.45 94.95 11 133.22 92.33 12 148.13 90.71 13 163.12 90.09 14 178.12 90.49 15 193.05 91.89 16 207.86 94.30 17 222.47 97.69 18 236.82 102.06 19 250.84 107.39 20 264.47 113.65 21 277.65 120.81 22 290.32 128.84 23 302.42 137.70 24 313.90 147.36 25 324.70 157.77 26 334.77 168.88 27 344.08 180.65 28 352.57 193.01 29 356.16 199.07 Circle Center At X = 164.74 ; Y = 312.95 ; and Radius = 222.86

Factor of Safety *** 1.367 ***

1 Failure Surface Specified By 30 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 7.63 160.32 2 18.29 149.77 3 29.59 139.91 4 41.50 130.78 5 53.96 122.43 6 66.92 114.88 7 80.33 108.16 8 94.14 102.31 9 108.29 97.34 10 122.73 93.27 11 137.40 90.12 12 152.23 87.90 13 167.18 86.63 14 182.17 86.30 15 197.16 86.93 16 212.08 88.49 17 226.87 91.00 18 241.47 94.43 19 255.83 98.78 20 269.88 104.03 21 283.57 110.16 22 296.85 117.14 23 309.66 124.94 24 321.95 133.53 25 333.67 142.89 26 344.79 152.97 27 355.24 163.73

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 9 of 11 28 364.99 175.13 29 374.00 187.12 30 381.72 198.87 Circle Center At X = 179.83 ; Y = 323.60 ; and Radius = 237.31

Factor of Safety *** 1.367 ***

Failure Surface Specified By 32 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 5.08 160.21 2 15.76 149.67 3 27.04 139.79 4 38.89 130.59 5 51.26 122.11 6 64.12 114.39 7 77.42 107.44 8 91.10 101.30 9 105.13 95.98 10 119.44 91.50 11 134.00 87.89 12 148.75 85.15 13 163.63 83.29 14 178.60 82.32 15 193.60 82.24 16 208.58 83.05 17 223.48 84.75 18 238.26 87.34 19 252.85 90.80 20 267.22 95.12 21 281.30 100.29 22 295.05 106.29 23 308.41 113.09 24 321.35 120.68 25 333.82 129.03 26 345.76 138.10 27 357.15 147.86 28 367.93 158.29 29 378.08 169.34 30 387.55 180.97 31 396.31 193.15 32 399.83 198.72 Circle Center At X = 187.38 ; Y = 334.05 ; and Radius = 251.89

Factor of Safety *** 1.368 ***

1 Failure Surface Specified By 31 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft)

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 10 of 11 1 7.63 160.32 2 18.29 149.76 3 29.57 139.89 4 41.45 130.72 5 53.86 122.30 6 66.77 114.65 7 80.12 107.81 8 93.86 101.81 9 107.95 96.66 10 122.33 92.38 11 136.94 88.99 12 151.73 86.51 13 166.65 84.94 14 181.64 84.28 15 196.63 84.55 16 211.59 85.74 17 226.44 87.84 18 241.13 90.85 19 255.62 94.76 20 269.83 99.54 21 283.73 105.19 22 297.25 111.68 23 310.35 118.99 24 322.97 127.09 25 335.08 135.95 26 346.61 145.54 27 357.54 155.81 28 367.82 166.74 29 377.41 178.27 30 386.27 190.38 31 391.67 198.79 Circle Center At X = 184.78 ; Y = 328.61 ; and Radius = 244.35

Factor of Safety *** 1.368 ***

Failure Surface Specified By 29 Coordinate Points

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT 2/21/2008 Page 11 of 11 22 298.39 126.47 23 310.67 135.09 24 322.35 144.50 25 333.38 154.67 26 343.71 165.54 27 353.30 177.08 28 362.10 189.22 29 368.23 198.97 Circle Center At X = 174.59 ; Y = 315.88 ; and Radius = 226.28

Factor of Safety *** 1.368 ***

**** END OF GSTABL7 OUTPUT ****

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-1.OUT

Analysis Run Date: 2/21/2008 Time of Run: 02:10PM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Global-Stabil\ Output Filename: C:\GEOTECHNICAL\saugus\2008\Global-Stabil\ Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Glob••••tabil\

PROBLEM DESCRIPTION: RESCO; Ash at 3H:1V to El. 50'; With Con solid. through 2008; Run#S1-Bc-2

BOUNDARY COORDINATES 5 Top Boundaries 24 Total Boundaries

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 2 of 10 23 240.00 90.00 600.00 90.00 19 24 0.00 60.00 600.00 60.00 20 Default Y-Origin = 0.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) 1

ISOTROPIC SOIL PARAMETERS

20 Type(s) of Soil

Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 100.0 100.0 0.0 40.0 0.00 0.0 1 2 75.0 75.0 0.0 28.0 0.00 0.0 1 3 100.0 100.0 1000.0 0.0 0.00 0.0 1 4 120.0 120.0 0.0 30.0 0.00 0.0 1 5 108.0 108.0 757.0 0.0 0.00 0.0 1 6 108.0 108.0 788.0 0.0 0.00 0.0 1 7 108.0 108.0 863.0 0.0 0.00 0.0 1 8 108.0 108.0 926.0 0.0 0.00 0.0 1 9 108.0 108.0 955.0 0.0 0.00 0.0 1 10 108.0 108.0 893.0 0.0 0.00 0.0 1 11 108.0 108.0 915.0 0.0 0.00 0.0 1 12 108.0 108.0 962.0 0.0 0.00 0.0 1 13 108.0 108.0 1004.0 0.0 0.00 0.0 1 14 108.0 108.0 1024.0 0.0 0.00 0.0 1 15 108.0 108.0 878.0 0.0 0.00 0.0 1 16 108.0 108.0 907.0 0.0 0.00 0.0 1 17 108.0 108.0 1087.0 0.0 0.00 0.0 1 18 108.0 108.0 1279.0 0.0 0.00 0.0 1 19 108.0 108.0 1383.0 0.0 0.00 0.0 1 20 130.0 130.0 0.0 34.0 0.00 0.0 1 1

1 PIEZOMETRIC SURFACE(S) SPECIFIED

Unit Weight of Water = 62.40 (pcf)

Piezometric Surface No. 1 Specified by 2 Coordinate Points Pore Pressure Inclination Factor = 0.50

Point X-Water Y-Water No. (ft) (ft) 1 0.00 153.00 2 600.00 154.00 1

A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified.

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 3 of 10 3600 Trial Surfaces Have Been Generated.

60 Surface(s) Initiate(s) From Each Of 60 Points Equally Spaced Along The Ground Surface Between X = 0.00(ft) and X = 150.00(ft)

Each Surface Terminates Between X = 200.00(ft) and X = 400.00(ft)

Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = 0.00(ft)

15.00(ft) Line Segments Define Each Trial Failure Surface.

Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First.

* * Safety Factors Are Calculated By The Modified Bishop Method * *

Total Number of Trial Surfaces Evaluated = 3600 Statistical Data On All Valid FS Values: FS Max = 7.439 FS Min = 1.599 FS Ave = 2.554 Standard Deviation = 0.780 Coefficient of Variation = 30.5

Failure Surface Specified By 29 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 2.54 160.11 2 13.19 149.54 3 24.53 139.72 4 36.50 130.68 5 49.05 122.47 6 62.12 115.11 7 75.66 108.66 8 89.61 103.13 9 103.89 98.55 10 118.45 94.95 11 133.22 92.33 12 148.13 90.71 13 163.12 90.09 14 178.12 90.49 15 193.05 91.89 16 207.86 94.30 17 222.47 97.69 18 236.82 102.06 19 250.84 107.39 20 264.47 113.65 21 277.65 120.81 22 290.32 128.84 23 302.42 137.70 24 313.90 147.36 25 324.70 157.77

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 4 of 10 26 334.77 168.88 27 344.08 180.65 28 352.57 193.01 29 356.16 199.07 Circle Center At X = 164.74 ; Y = 312.95 ; and Radius = 222.86

Factor of Safety *** 1.599 ***

Individual data on the 44 slices

Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 7.1 1979.8 0.0 0.0 0. 0. 0.0 0.0 2 3.0 2042.8 0.0 403.7 0. 0. 0.0 0.0 3 0.5 375.8 0.0 132.0 0. 0. 0.0 0.0 4 7.5 8876.1 0.0 4211.7 0. 0. 0.0 0.0 5 3.8 6505.1 0.0 3652.2 0. 0. 0.0 0.0 6 2.3 4611.3 0.0 2522.9 0. 0. 0.0 0.0 7 9.7 24668.4 0.0 14187.2 0. 0. 0.0 0.0 8 12.6 42899.6 0.0 24803.5 0. 0. 0.0 0.0 9 4.4 17631.7 0.0 9998.3 0. 0. 0.0 0.0 10 8.7 38572.2 0.0 22109.2 0. 0. 0.0 0.0 11 13.5 68859.0 0.0 38589.0 0. 0. 0.0 0.0 12 13.9 80532.9 0.0 44218.6 0. 0. 0.0 0.0 13 14.3 90924.9 0.0 48970.9 0. 0. 0.0 0.0 14 14.6 99771.3 0.0 52824.3 0. 0. 0.0 0.0 15 1.5 10970.5 0.0 5727.9 0. 0. 0.0 0.0 16 13.2 96700.2 0.0 50033.4 0. 0. 0.0 0.0 17 14.9 114880.7 0.0 57768.7 0. 0. 0.0 0.0 18 1.9 14743.3 0.0 7293.6 0. 0. 0.0 0.0 19 10.0 81048.2 0.0 39241.1 0. 0. 0.0 0.0 20 3.1 26070.5 0.0 12302.7 0. 0. 0.0 0.0 21 15.0 129554.0 0.0 58962.4 0. 0. 0.0 0.0 22 14.9 135028.1 0.0 58143.4 0. 0. 0.0 0.0 23 6.9 64421.3 0.0 26743.7 0. 0. 0.0 0.0 24 7.9 73740.4 0.0 29640.1 0. 0. 0.0 0.0 25 14.6 138925.2 0.0 53691.9 0. 0. 0.0 0.0 26 14.3 137346.0 0.0 50079.6 0. 0. 0.0 0.0 27 3.2 30450.5 0.0 10782.4 0. 0. 0.0 0.0 28 10.8 101053.1 0.0 34781.1 0. 0. 0.0 0.0 29 13.6 119336.0 0.0 40163.9 0. 0. 0.0 0.0 30 11.7 94275.8 0.0 30412.4 0. 0. 0.0 0.0 31 1.5 11413.5 0.0 3492.9 0. 0. 0.0 0.0 32 12.7 91064.1 0.0 26816.1 0. 0. 0.0 0.0 33 12.1 75815.2 0.0 18928.3 0. 0. 0.0 0.0 34 0.4 2029.4 0.0 449.3 0. 0. 0.0 0.0 35 5.9 32363.4 0.0 6303.7 0. 0. 0.0 0.0 36 5.2 25527.9 0.0 3524.8 0. 0. 0.0 0.0 37 2.7 12512.2 0.0 1148.9 0. 0. 0.0 0.0 38 3.7 15785.1 0.0 560.5 0. 0. 0.0 0.0 39 4.4 17632.1 0.0 0.0 0. 0. 0.0 0.0 40 10.1 34548.0 0.0 0.0 0. 0. 0.0 0.0 41 0.9 2620.5 0.0 0.0 0. 0. 0.0 0.0 42 8.4 20110.3 0.0 0.0 0. 0. 0.0 0.0 43 8.5 10450.5 0.0 0.0 0. 0. 0.0 0.0 44 3.6 1092.3 0.0 0.0 0. 0. 0.0 0.0 Failure Surface Specified By 29 Coordinate Points

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 5 of 10

Factor of Safety *** 1.602 ***

1 Failure Surface Specified By 28 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 5.08 160.21 2 15.71 149.63 3 27.04 139.80 4 39.02 130.77 5 51.59 122.59 6 64.70 115.29 7 78.28 108.92 8 92.26 103.49 9 106.59 99.05 10 121.19 95.59 11 135.99 93.16 12 150.92 91.74 13 165.92 91.36 14 180.90 92.01 15 195.81 93.69 16 210.56 96.40 17 225.09 100.11

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 6 of 10 18 239.34 104.82 19 253.22 110.49 20 266.68 117.11 21 279.66 124.64 22 292.08 133.05 23 303.90 142.29 24 315.05 152.32 25 325.48 163.10 26 335.15 174.57 27 344.00 186.67 28 351.84 199.11 Circle Center At X = 163.95 ; Y = 309.04 ; and Radius = 217.69

Factor of Safety *** 1.604 ***

Failure Surface Specified By 28 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 5.08 160.21 2 15.73 149.64 3 27.09 139.85 4 39.11 130.87 5 51.73 122.76 6 64.88 115.56 7 78.51 109.29 8 92.54 103.99 9 106.91 99.69 10 121.55 96.41 11 136.38 94.17 12 151.33 92.96 13 166.33 92.81 14 181.31 93.71 15 196.18 95.66 16 210.88 98.65 17 225.33 102.65 18 239.47 107.67 19 253.22 113.66 20 266.52 120.60 21 279.30 128.45 22 291.50 137.18 23 303.05 146.75 24 313.91 157.10 25 324.01 168.18 26 333.32 179.95 27 341.77 192.34 28 345.75 199.15 Circle Center At X = 160.93 ; Y = 306.45 ; and Radius = 213.71

Factor of Safety *** 1.608 ***

1 Failure Surface Specified By 28 Coordinate Points

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 7 of 10

Point X-Surf Y-Surf No. (ft) (ft) 1 12.71 160.53 2 23.36 149.97 3 34.74 140.19 4 46.78 131.25 5 59.43 123.19 6 72.62 116.05 7 86.29 109.86 8 100.36 104.66 9 114.76 100.47 10 129.43 97.32 11 144.28 95.22 12 159.24 94.18 13 174.24 94.21 14 189.20 95.31 15 204.05 97.46 16 218.70 100.67 17 233.09 104.91 18 247.14 110.16 19 260.78 116.40 20 273.94 123.59 21 286.56 131.71 22 298.57 140.69 23 309.91 150.51 24 320.52 161.11 25 330.36 172.44 26 339.36 184.44 27 347.48 197.05 28 348.62 199.13 Circle Center At X = 166.31 ; Y = 304.77 ; and Radius = 210.71

Factor of Safety *** 1.611 ***

Failure Surface Specified By 27 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 20.34 160.85 2 30.97 150.27 3 42.36 140.50 4 54.43 131.59 5 67.12 123.59 6 80.36 116.55 7 94.08 110.50 8 108.21 105.46 9 122.68 101.48 10 137.39 98.58 11 152.28 96.76 12 167.26 96.03 13 182.26 96.41 14 197.18 97.89 15 211.96 100.46 16 226.51 104.10 17 240.76 108.81 18 254.62 114.54 19 268.02 121.28 20 280.89 128.99

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 8 of 10 21 293.16 137.61 22 304.76 147.12 23 315.64 157.45 24 325.73 168.55 25 334.97 180.36 26 343.33 192.82 27 346.93 199.14 Circle Center At X = 169.61 ; Y = 300.29 ; and Radius = 204.27

Factor of Safety *** 1.614 ***

1 Failure Surface Specified By 28 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 10.74 149.53 3 22.17 139.82 4 34.24 130.91 5 46.89 122.86 6 60.07 115.69 7 73.71 109.44 8 87.74 104.14 9 102.10 99.82 10 116.73 96.49 11 131.55 94.18 12 146.50 92.88 13 161.49 92.62 14 176.47 93.38 15 191.37 95.17 16 206.10 97.98 17 220.61 101.79 18 234.82 106.59 19 248.67 112.35 20 262.09 119.05 21 275.02 126.65 22 287.40 135.13 23 299.17 144.43 24 310.27 154.51 25 320.65 165.34 26 330.27 176.85 27 339.08 188.99 28 345.43 199.16 Circle Center At X = 157.82 ; Y = 311.01 ; and Radius = 218.42

Factor of Safety *** 1.617 ***

Failure Surface Specified By 27 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft)

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 9 of 10 1 25.42 161.06 2 36.04 150.46 3 47.39 140.66 4 59.43 131.71 5 72.09 123.66 6 85.30 116.55 7 98.99 110.42 8 113.08 105.30 9 127.52 101.21 10 142.21 98.19 11 157.08 96.24 12 172.06 95.38 13 187.06 95.61 14 202.00 96.93 15 216.81 99.33 16 231.40 102.80 17 245.70 107.32 18 259.64 112.87 19 273.13 119.41 20 286.12 126.92 21 298.52 135.35 22 310.28 144.67 23 321.34 154.81 24 331.62 165.73 25 341.09 177.36 26 349.68 189.66 27 355.30 199.08 Circle Center At X = 176.42 ; Y = 301.64 ; and Radius = 206.31

Factor of Safety *** 1.617 ***

1 Failure Surface Specified By 27 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 5.08 160.21 2 15.70 149.61 3 27.05 139.80 4 39.08 130.84 5 51.72 122.78 6 64.92 115.65 7 78.60 109.49 8 92.69 104.34 9 107.11 100.23 10 121.80 97.16 11 136.66 95.17 12 151.64 94.26 13 166.63 94.44 14 181.58 95.69 15 196.40 98.03 16 211.01 101.44 17 225.33 105.89 18 239.30 111.37 19 252.83 117.84 20 265.85 125.27 21 278.31 133.63 22 290.13 142.87 23 301.25 152.94 24 311.61 163.78

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT 2/21/2008 Page 10 of 10 25 321.16 175.35 26 329.84 187.58 27 336.91 199.22 Circle Center At X = 156.72 ; Y = 301.37 ; and Radius = 207.17

Factor of Safety *** 1.618 ***

Failure Surface Specified By 29 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 10.17 160.42 2 20.83 149.87 3 32.17 140.05 4 44.13 131.00 5 56.66 122.76 6 69.72 115.37 7 83.23 108.86 8 97.15 103.27 9 111.41 98.60 10 125.94 94.89 11 140.69 92.16 12 155.59 90.40 13 170.57 89.64 14 185.56 89.87 15 200.51 91.09 16 215.35 93.30 17 230.01 96.49 18 244.42 100.64 19 258.53 105.74 20 272.27 111.77 21 285.57 118.69 22 298.39 126.47 23 310.67 135.09 24 322.35 144.50 25 333.38 154.67 26 343.71 165.54 27 353.30 177.08 28 362.10 189.22 29 368.23 198.97 Circle Center At X = 174.59 ; Y = 315.88 ; and Radius = 226.28

Factor of Safety *** 1.618 ***

**** END OF GSTABL7 OUTPUT ****

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\s1-bc-2.OUT Table 1 Boston Blue Clay Consolidation Calculations Cross Section Across Phase III Saugus RESCO Landfill

1. Consolidation from Existing MSW Based on ash residue filling at 3H:1V to elevation 50 feet MSL Approximate year the MSW filling started = 1955 Approximate year MSW filling ended = 1985

Assuming the waste filling took place linearly t0 = 30 years Year when percent of consolidation required 2008 t = 53 years

Based on the 1999 analysis, Cv for the clay cv = 0.2 ft2/day Total thickness of clay 2H = 78 ft2/day Assuming two-way drainage H = 39 ft

2 T0 = C v . t 0/H T0 = 1.44 2 T = C v . t/H T = 2.54

T-T 0 = 1.10

Soil Nos. z z/H up/u 0(T) up/u 0(T-T 0)T0.u/u 0 u/u 0 % Consol. (see Note 1) (See Note 2) (See Note 2) 5, 6, 7, 8, & 9 9 0.23 0.001 0.015 0.014 0.01 99 10, 11, 12, 13, &14 33 0.85 0.0032 0.04 0.0368 0.03 97 15, 16, 17, 18, & 19 15 0.38 0.002 0.025 0.023 0.02 98

2. Consolidation from Ash Residue Based on ash residue filling at 3H:1V to elevation 50 feet MSL Approximate year the ash filling started = 1985 Year when percent consolidation required = 2008

Assuming the filling to be linear t0 = t = 23 2 T =T 0 = C v . t 0/H T0 = T = 1.10

2 uz/u 0 = (z/H) - (0.5)(z/H)

Soil Nos. z z/H uz/u 0 up/u 0(T) T0.u/u 0 u/u 0 % Consol. (See Note) 5, 6, 7, 8, & 9 9 0.23 0.204 0.015 0.189 0.17 83 10, 11, 12, 13, &14 33 0.85 0.488 0.04 0.448 0.41 59 15, 16, 17, 18, & 19 15 0.38 0.311 0.025 0.286 0.26 74

σ'vc Consolidation from MSW Consolidation from Ash ∆σ 'vc σ'vc + ∆σ 'vc

Soil No. Soil Elev. Effect. OCR Original S u MSW Ht. MSW Wt. % Consol. Stress Incr. Ash Ht. Ash Wt. % Consol. Stress Incr. Total Stress New Effect. New OCR New S u Stress (see Note 1) (see Note 2) Increase Stress (see Note 3) (ft) (psf) (psf) (ft) (psf) (psf) (ft) (psf) (psf) (psf) (psf) (psf) 1 Ash 2 MSW 3 Peat 1000 4 Silt/Sand 5 Med. BBC -21.0 957.6 5 656 12.5 813 99 804 0 0 83 0 804 1762 2.72 757 6 Med. BBC -21.0 957.6 5 656 17.5 1138 99 1126 0 0 83 0 1126 2084 2.30 788 7 Med. BBC -21.0 957.6 5 656 20.0 1300 99 1287 10 1000 83 830 2117 3075 1.56 863 8 Med. BBC -21.0 957.6 5 656 20.0 1300 99 1287 23 2300 83 1909 3196 4154 1.15 926 9 Med. BBC -21.0 957.6 5 656 20.0 1300 99 1287 30 3000 83 2490 3777 4735 1.01 955 10 Soft BBC -45.0 2052 2.5 827 12.5 813 97 788 0 0 59 0 788 2840 1.81 893 11 Soft BBC -45.0 2052 2.5 827 17.5 1138 97 1103 0 0 59 0 1103 3155 1.63 915 12 Soft BBC -45.0 2052 2.5 827 20.0 1300 97 1261 10 1000 59 590 1851 3903 1.31 962 13 Soft BBC -45.0 2052 2.5 827 20.0 1300 97 1261 23 2300 59 1357 2618 4670 1.10 1004 14 Soft BBC -45.0 2052 2.5 827 20.0 1300 97 1261 30 3000 59 1770 3031 5083 1.01 1024 15 Soft BBC -75.0 3420 1.3 836 12.5 813 98 796 0 0 74 0 796 4216 1.05 878 16 Soft BBC -75.0 3420 1.3 836 17.5 1138 98 1115 0 0 74 0 1115 4535 1.00 907 17 Soft BBC -75.0 3420 1.3 836 20.0 1300 98 1274 10 1000 74 740 2014 5434 1.00 1087 18 Soft BBC -75.0 3420 1.3 836 20.0 1300 98 1274 23 2300 74 1702 2976 6396 1.00 1279 19 Soft BBC -75.0 3420 1.3 836 20.0 1300 98 1274 30 3000 74 2220 3494 6914 1.00 1383

Notes: 1. Over-consolidation ratio (OCR) based on MIT data from Route I-95 test fill S = )(2.0( σ ′ )( OCR ) .0 765 2. The undrained shear strength (S u) values for BBC were obtained using the following SHANSEP relationship: u vc .0 765 3. The undrained shear strength (Su) values were obtained using the following SHANSEP relationship: Su = )(2.0( σ vc′ + ∆′σ vc )( OCR )

B-3 Probabilistic Seismic Hazard Based on USGS

N:\projects\119504\2008\VF FEP Docs\Global Stability

3/3/2008 Page 1 of 7 *** Deaggregation of Seismic Hazard for PGA & 2 Periods of Spectral Accel. *** *** Data from U.S.G.S. National Seismic Hazards Mapping Project, 2002 version PSHA Deaggregation. %contributions. site: RESCO long: 70.985 W., lat: 42.438 USGS 2002-03 update files and programs. dM=0.2. Site descr:ROCK Return period: 2475 yrs. Exceedance PGA =0.1604 g. #Pr[at least one eq with median motion>=PGA in 50 yrs]=0.00950 DIST(KM) MAG(MW) ALL_EPS EPSILON>2 1

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\Deaggregation.txt 3/3/2008 Page 2 of 7 35.9 7.00 1.341 0.030 0.218 0.548 0.473 0.069 0.002 63.3 7.00 1.123 0.050 0.320 0.662 0.091 0.000 0.000 89.1 7.00 0.573 0.043 0.271 0.258 0.000 0.000 0.000 120.4 7.01 0.726 0.074 0.442 0.210 0.000 0.000 0.000 131.7 6.98 0.130 0.032 0.098 0.000 0.000 0.000 0.000 168.9 7.01 0.267 0.061 0.204 0.002 0.000 0.000 0.000 178.5 6.99 0.058 0.033 0.025 0.000 0.000 0.000 0.000 219.8 7.01 0.101 0.059 0.042 0.000 0.000 0.000 0.000 12.5 7.18 0.381 0.000 0.023 0.144 0.147 0.059 0.008 36.0 7.19 0.860 0.017 0.134 0.338 0.312 0.057 0.002 63.1 7.18 0.697 0.027 0.170 0.398 0.102 0.000 0.000 87.9 7.19 0.434 0.026 0.164 0.244 0.000 0.000 0.000 114.6 7.18 0.293 0.024 0.134 0.135 0.000 0.000 0.000 129.5 7.19 0.341 0.035 0.197 0.109 0.000 0.000 0.000 159.7 7.19 0.114 0.019 0.079 0.016 0.000 0.000 0.000 180.1 7.19 0.153 0.038 0.116 0.000 0.000 0.000 0.000 229.7 7.19 0.068 0.034 0.033 0.000 0.000 0.000 0.000 12.0 7.39 0.559 0.000 0.025 0.213 0.220 0.088 0.013 35.9 7.39 1.199 0.020 0.179 0.456 0.441 0.099 0.004 63.8 7.38 1.042 0.036 0.227 0.556 0.221 0.003 0.000 89.5 7.38 0.583 0.028 0.181 0.356 0.018 0.000 0.000 119.9 7.40 0.730 0.040 0.254 0.434 0.002 0.000 0.000 131.1 7.37 0.287 0.033 0.178 0.077 0.000 0.000 0.000 168.8 7.40 0.367 0.049 0.222 0.096 0.000 0.000 0.000 181.9 7.37 0.116 0.027 0.089 0.000 0.000 0.000 0.000 219.7 7.40 0.201 0.051 0.150 0.000 0.000 0.000 0.000 271.2 7.40 0.116 0.064 0.051 0.000 0.000 0.000 0.000 338.1 7.40 0.070 0.070 0.000 0.000 0.000 0.000 0.000 Summary statistics for above PSHA PGA deaggregation, R=distance, e=epsilon: Mean src-site R= 42.2 km; M= 5.80; eps0= -0.03. Mean calculated for all so Modal src-site R= 15.2 km; M= 4.80; eps0= -0.20 from peak (R,M) bin Gridded source distance metrics: Rseis Rrup and Rjb MODE R*= 14.8km; M*= 4.80; EPS.INTERVAL: 0 to 1 sigma % CONTRIB.= 4.464 Principal sources (faults, subduction, random seismicity having >10% contribut Source Category: % contr. R(km) M epsilon0 (mean values) CEUS gridded seism. 100.00 42.2 5.80 -0.03 Individual fault hazard details if contrib.>1%: ********************Central or Eastern U.S. Site ***************************** PSHA Deaggregation. %contributions. ROCK site: RESCO long: 70.985 d W., lat: USGS 2002-2003 update files and programs. Analysis on DaMoYr:04/03/2008 Return period: 2475 yrs. 1.00 s. PSA =0.06933 g. #Pr[at least one eq with median motion>=PSA in 50 yrs]=0.00577 DIST(km) MAG(Mw) ALL_EPS EPSILON>2 1

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\Deaggregation.txt 3/3/2008 Page 3 of 7 122.2 5.82 0.592 0.359 0.232 0.000 0.000 0.000 0.000 162.5 5.85 0.114 0.092 0.022 0.000 0.000 0.000 0.000 177.0 5.80 0.150 0.150 0.000 0.000 0.000 0.000 0.000 220.6 5.83 0.089 0.089 0.000 0.000 0.000 0.000 0.000 15.6 6.01 1.395 0.044 0.281 0.640 0.390 0.039 0.000 36.5 6.01 1.565 0.120 0.606 0.782 0.057 0.000 0.000 63.6 6.01 1.166 0.183 0.735 0.248 0.000 0.000 0.000 90.0 6.01 0.560 0.137 0.405 0.018 0.000 0.000 0.000 120.6 6.02 0.859 0.258 0.601 0.000 0.000 0.000 0.000 136.7 5.97 0.126 0.075 0.051 0.000 0.000 0.000 0.000 171.1 6.02 0.489 0.261 0.228 0.000 0.000 0.000 0.000 217.1 6.05 0.125 0.100 0.025 0.000 0.000 0.000 0.000 229.5 5.98 0.105 0.105 0.000 0.000 0.000 0.000 0.000 271.9 6.02 0.141 0.141 0.000 0.000 0.000 0.000 0.000 318.6 6.06 0.055 0.055 0.000 0.000 0.000 0.000 0.000 361.5 6.02 0.102 0.102 0.000 0.000 0.000 0.000 0.000 13.4 6.21 1.175 0.032 0.205 0.494 0.381 0.061 0.001 34.9 6.21 2.085 0.111 0.641 1.095 0.237 0.000 0.000 63.4 6.22 1.511 0.181 0.813 0.516 0.001 0.000 0.000 90.0 6.22 0.794 0.154 0.536 0.104 0.000 0.000 0.000 120.5 6.22 0.953 0.168 0.729 0.057 0.000 0.000 0.000 129.3 6.21 0.469 0.194 0.275 0.000 0.000 0.000 0.000 170.1 6.22 0.619 0.199 0.421 0.000 0.000 0.000 0.000 178.2 6.21 0.168 0.099 0.069 0.000 0.000 0.000 0.000 220.0 6.23 0.219 0.126 0.093 0.000 0.000 0.000 0.000 227.1 6.21 0.191 0.099 0.092 0.000 0.000 0.000 0.000 269.7 6.24 0.201 0.149 0.052 0.000 0.000 0.000 0.000 282.2 6.19 0.083 0.083 0.000 0.000 0.000 0.000 0.000 343.6 6.21 0.114 0.114 0.000 0.000 0.000 0.000 0.000 355.3 6.24 0.208 0.208 0.000 0.000 0.000 0.000 0.000 411.9 6.22 0.073 0.073 0.000 0.000 0.000 0.000 0.000 14.1 6.42 0.920 0.023 0.144 0.361 0.316 0.073 0.002 35.5 6.42 1.678 0.067 0.419 0.824 0.361 0.006 0.000 61.5 6.42 1.250 0.103 0.477 0.628 0.041 0.000 0.000 86.4 6.42 1.110 0.115 0.534 0.461 0.000 0.000 0.000 123.2 6.42 1.585 0.211 0.955 0.419 0.000 0.000 0.000 127.0 6.42 0.056 0.042 0.014 0.000 0.000 0.000 0.000 164.5 6.46 0.443 0.089 0.301 0.053 0.000 0.000 0.000 178.3 6.40 0.557 0.145 0.412 0.000 0.000 0.000 0.000 222.0 6.43 0.500 0.149 0.351 0.000 0.000 0.000 0.000 234.5 6.38 0.086 0.054 0.032 0.000 0.000 0.000 0.000 263.3 6.46 0.143 0.070 0.073 0.000 0.000 0.000 0.000 278.9 6.41 0.312 0.148 0.164 0.000 0.000 0.000 0.000 333.5 6.45 0.404 0.284 0.120 0.000 0.000 0.000 0.000 404.9 6.42 0.445 0.445 0.000 0.000 0.000 0.000 0.000 554.6 6.44 0.109 0.109 0.000 0.000 0.000 0.000 0.000 15.2 6.59 0.678 0.016 0.104 0.261 0.234 0.060 0.003 36.9 6.60 1.049 0.037 0.237 0.495 0.269 0.010 0.000 64.0 6.60 1.070 0.066 0.369 0.578 0.057 0.000 0.000 89.8 6.60 0.638 0.058 0.286 0.293 0.002 0.000 0.000 118.0 6.60 0.708 0.074 0.304 0.331 0.000 0.000 0.000 130.2 6.59 0.568 0.069 0.377 0.122 0.000 0.000 0.000 171.7 6.60 0.753 0.107 0.474 0.172 0.000 0.000 0.000 180.7 6.57 0.067 0.039 0.028 0.000 0.000 0.000 0.000 214.4 6.60 0.219 0.068 0.143 0.008 0.000 0.000 0.000 230.7 6.60 0.307 0.075 0.232 0.000 0.000 0.000 0.000 273.4 6.60 0.373 0.105 0.267 0.000 0.000 0.000 0.000 278.6 6.59 0.052 0.052 0.000 0.000 0.000 0.000 0.000 309.2 6.62 0.070 0.021 0.049 0.000 0.000 0.000 0.000 363.8 6.60 0.621 0.354 0.267 0.000 0.000 0.000 0.000 410.3 6.57 0.136 0.136 0.000 0.000 0.000 0.000 0.000 451.3 6.63 0.085 0.085 0.000 0.000 0.000 0.000 0.000 540.6 6.61 0.116 0.116 0.000 0.000 0.000 0.000 0.000 594.6 6.60 0.094 0.094 0.000 0.000 0.000 0.000 0.000 13.2 6.79 0.802 0.018 0.116 0.291 0.283 0.088 0.006 35.7 6.78 1.698 0.052 0.327 0.755 0.521 0.044 0.000 62.1 6.79 1.469 0.073 0.444 0.763 0.189 0.000 0.000 87.1 6.78 1.306 0.082 0.477 0.730 0.018 0.000 0.000

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\Deaggregation.txt 3/3/2008 Page 4 of 7 122.7 6.79 1.639 0.126 0.669 0.844 0.000 0.000 0.000 126.6 6.77 0.524 0.049 0.313 0.162 0.000 0.000 0.000 169.8 6.80 0.894 0.073 0.444 0.377 0.000 0.000 0.000 177.2 6.77 0.585 0.107 0.397 0.080 0.000 0.000 0.000 223.4 6.79 0.850 0.113 0.571 0.165 0.000 0.000 0.000 228.3 6.77 0.166 0.083 0.083 0.000 0.000 0.000 0.000 269.8 6.82 0.378 0.130 0.226 0.022 0.000 0.000 0.000 277.5 6.77 0.494 0.119 0.375 0.000 0.000 0.000 0.000 339.9 6.80 0.852 0.205 0.646 0.000 0.000 0.000 0.000 387.6 6.79 0.309 0.309 0.000 0.000 0.000 0.000 0.000 407.1 6.78 0.936 0.518 0.418 0.000 0.000 0.000 0.000 525.7 6.86 0.072 0.063 0.009 0.000 0.000 0.000 0.000 564.9 6.78 0.171 0.171 0.000 0.000 0.000 0.000 0.000 577.3 6.80 0.342 0.342 0.000 0.000 0.000 0.000 0.000 628.8 6.80 0.056 0.056 0.000 0.000 0.000 0.000 0.000 12.7 7.00 0.572 0.013 0.080 0.201 0.201 0.071 0.007 36.0 7.00 1.272 0.034 0.216 0.532 0.420 0.069 0.001 64.3 7.00 1.334 0.051 0.325 0.649 0.307 0.002 0.000 89.7 7.00 0.882 0.042 0.264 0.480 0.096 0.000 0.000 121.0 7.01 1.316 0.063 0.400 0.773 0.080 0.000 0.000 131.8 6.98 0.578 0.043 0.265 0.270 0.000 0.000 0.000 172.9 7.01 1.192 0.082 0.497 0.613 0.001 0.000 0.000 177.7 6.99 0.187 0.025 0.126 0.036 0.000 0.000 0.000 217.9 7.03 0.417 0.039 0.198 0.180 0.000 0.000 0.000 229.0 6.99 0.655 0.084 0.406 0.165 0.000 0.000 0.000 273.8 7.01 0.781 0.096 0.510 0.175 0.000 0.000 0.000 278.4 6.99 0.187 0.068 0.120 0.000 0.000 0.000 0.000 318.3 7.04 0.324 0.039 0.249 0.036 0.000 0.000 0.000 371.0 7.00 0.925 0.194 0.731 0.000 0.000 0.000 0.000 385.8 7.01 0.915 0.363 0.552 0.000 0.000 0.000 0.000 424.1 6.99 0.479 0.304 0.176 0.000 0.000 0.000 0.000 557.3 7.02 0.596 0.425 0.171 0.000 0.000 0.000 0.000 595.1 6.97 0.256 0.256 0.000 0.000 0.000 0.000 0.000 612.2 7.01 0.056 0.056 0.000 0.000 0.000 0.000 0.000 639.1 7.01 0.090 0.090 0.000 0.000 0.000 0.000 0.000 12.4 7.18 0.375 0.008 0.052 0.130 0.130 0.049 0.005 36.0 7.19 0.834 0.021 0.133 0.335 0.285 0.059 0.001 63.0 7.19 0.750 0.025 0.161 0.349 0.211 0.004 0.000 87.2 7.18 0.695 0.027 0.171 0.365 0.132 0.000 0.000 124.1 7.19 1.038 0.046 0.294 0.550 0.148 0.000 0.000 126.7 7.16 0.261 0.013 0.084 0.164 0.000 0.000 0.000 166.0 7.20 0.360 0.018 0.114 0.206 0.021 0.000 0.000 178.6 7.18 0.634 0.043 0.270 0.321 0.000 0.000 0.000 224.0 7.19 0.657 0.046 0.289 0.323 0.000 0.000 0.000 227.8 7.20 0.173 0.026 0.128 0.019 0.000 0.000 0.000 268.8 7.18 0.374 0.052 0.232 0.090 0.000 0.000 0.000 280.0 7.20 0.414 0.044 0.230 0.139 0.000 0.000 0.000 342.0 7.19 0.846 0.090 0.569 0.187 0.000 0.000 0.000 374.4 7.16 0.307 0.170 0.137 0.000 0.000 0.000 0.000 392.7 7.23 0.121 0.063 0.058 0.000 0.000 0.000 0.000 404.2 7.19 0.860 0.173 0.687 0.000 0.000 0.000 0.000 458.8 7.18 0.072 0.072 0.000 0.000 0.000 0.000 0.000 529.1 7.23 0.050 0.015 0.035 0.000 0.000 0.000 0.000 573.5 7.16 0.309 0.153 0.155 0.000 0.000 0.000 0.000 575.3 7.23 0.274 0.147 0.127 0.000 0.000 0.000 0.000 608.5 7.16 0.116 0.116 0.000 0.000 0.000 0.000 0.000 629.2 7.23 0.059 0.059 0.000 0.000 0.000 0.000 0.000 12.0 7.39 0.553 0.012 0.076 0.191 0.191 0.075 0.009 36.0 7.39 1.181 0.028 0.179 0.449 0.416 0.105 0.003 64.5 7.38 1.202 0.036 0.227 0.551 0.372 0.016 0.000 89.8 7.38 0.819 0.028 0.178 0.408 0.205 0.000 0.000 119.3 7.41 0.696 0.021 0.130 0.327 0.218 0.000 0.000 128.1 7.37 1.213 0.052 0.332 0.697 0.131 0.000 0.000 172.8 7.39 1.278 0.054 0.346 0.745 0.133 0.000 0.000 181.2 7.36 0.283 0.021 0.135 0.127 0.000 0.000 0.000 222.1 7.40 0.713 0.034 0.214 0.447 0.019 0.000 0.000 227.6 7.38 0.730 0.059 0.376 0.294 0.000 0.000 0.000 273.4 7.40 1.115 0.082 0.518 0.515 0.000 0.000 0.000

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\Deaggregation.txt 3/3/2008 Page 5 of 7 281.0 7.36 0.300 0.041 0.219 0.039 0.000 0.000 0.000 322.8 7.43 0.467 0.029 0.186 0.252 0.000 0.000 0.000 370.4 7.39 1.592 0.274 1.165 0.153 0.000 0.000 0.000 381.0 7.39 1.283 0.123 0.783 0.377 0.000 0.000 0.000 403.9 7.38 0.313 0.062 0.251 0.000 0.000 0.000 0.000 428.3 7.37 0.471 0.229 0.243 0.000 0.000 0.000 0.000 563.5 7.41 1.021 0.246 0.775 0.000 0.000 0.000 0.000 591.4 7.38 0.173 0.093 0.080 0.000 0.000 0.000 0.000 607.7 7.39 0.693 0.567 0.126 0.000 0.000 0.000 0.000 Summary statistics for above 1.0s PSA deaggregation, R=distance, e=epsilon: Mean src-site R= 161.3 km; M= 6.62; eps0= 0.51. Mean calculated for all so Modal src-site R= 34.9 km; M= 6.21; eps0= -0.02 from peak (R,M) bin Gridded source distance metrics: Rseis Rrup and Rjb MODE R*= 370.6km; M*= 7.39; EPS.INTERVAL: 1 to 2 sigma % CONTRIB.= 1.165 Principal sources (faults, subduction, random seismicity having >10% contribut Source Category: % contr. R(km) M epsilon0 (mean values) CEUS gridded seism. 100.00 161.3 6.62 0.51 Individual fault hazard details if contrib.>1%: ********************Central or Eastern U.S. Site ***************************** PSHA Deaggregation. %contributions. ROCK site: RESCO long: 70.985 d W., lat: USGS 2002-2003 update files and programs. Analysis on DaMoYr:04/03/2008 Return period: 2475 yrs. 0.20 s. PSA =0.2950 g. #Pr[at least one eq with median motion>=PSA in 50 yrs]=0.00759 DIST(km) MAG(Mw) ALL_EPS EPSILON>2 1

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\Deaggregation.txt 3/3/2008 Page 6 of 7 163.3 6.23 0.217 0.147 0.070 0.000 0.000 0.000 0.000 180.5 6.20 0.111 0.111 0.000 0.000 0.000 0.000 0.000 216.1 6.24 0.061 0.061 0.000 0.000 0.000 0.000 0.000 16.4 6.42 1.259 0.018 0.177 0.465 0.465 0.127 0.006 36.9 6.42 1.758 0.062 0.391 0.944 0.361 0.000 0.000 62.8 6.42 1.440 0.113 0.698 0.626 0.003 0.000 0.000 89.0 6.42 0.731 0.106 0.543 0.082 0.000 0.000 0.000 121.1 6.43 1.020 0.218 0.791 0.012 0.000 0.000 0.000 134.3 6.40 0.073 0.037 0.037 0.000 0.000 0.000 0.000 166.0 6.43 0.267 0.129 0.138 0.000 0.000 0.000 0.000 177.1 6.42 0.144 0.083 0.061 0.000 0.000 0.000 0.000 217.4 6.43 0.084 0.078 0.005 0.000 0.000 0.000 0.000 13.3 6.59 0.590 0.005 0.075 0.214 0.214 0.076 0.005 35.5 6.59 1.335 0.041 0.260 0.648 0.367 0.019 0.000 62.0 6.60 0.921 0.057 0.357 0.497 0.010 0.000 0.000 87.1 6.59 0.639 0.067 0.397 0.175 0.000 0.000 0.000 115.2 6.60 0.484 0.054 0.346 0.084 0.000 0.000 0.000 130.7 6.59 0.395 0.089 0.305 0.000 0.000 0.000 0.000 164.5 6.60 0.247 0.073 0.173 0.000 0.000 0.000 0.000 182.7 6.60 0.116 0.055 0.061 0.000 0.000 0.000 0.000 216.7 6.60 0.098 0.067 0.031 0.000 0.000 0.000 0.000 13.0 6.78 0.817 0.004 0.094 0.298 0.298 0.114 0.010 35.6 6.78 1.874 0.051 0.332 0.833 0.611 0.047 0.000 63.3 6.78 1.617 0.084 0.534 0.944 0.055 0.000 0.000 89.5 6.79 0.877 0.071 0.449 0.357 0.000 0.000 0.000 121.9 6.79 1.405 0.152 0.864 0.389 0.000 0.000 0.000 133.2 6.77 0.097 0.024 0.073 0.000 0.000 0.000 0.000 170.0 6.79 0.655 0.143 0.498 0.014 0.000 0.000 0.000 215.7 6.81 0.117 0.053 0.065 0.000 0.000 0.000 0.000 226.7 6.78 0.165 0.086 0.079 0.000 0.000 0.000 0.000 261.2 6.83 0.060 0.048 0.012 0.000 0.000 0.000 0.000 279.7 6.77 0.076 0.076 0.000 0.000 0.000 0.000 0.000 12.7 7.00 0.584 0.001 0.052 0.217 0.218 0.086 0.010 36.0 7.00 1.346 0.032 0.218 0.547 0.487 0.063 0.001 62.8 7.01 1.144 0.045 0.289 0.667 0.143 0.000 0.000 87.6 7.00 0.838 0.048 0.303 0.487 0.001 0.000 0.000 117.2 7.02 0.659 0.040 0.252 0.368 0.000 0.000 0.000 129.2 6.99 0.664 0.066 0.394 0.204 0.000 0.000 0.000 166.5 7.02 0.399 0.042 0.265 0.092 0.000 0.000 0.000 179.7 6.99 0.269 0.066 0.204 0.000 0.000 0.000 0.000 219.9 7.02 0.251 0.067 0.183 0.000 0.000 0.000 0.000 232.3 6.98 0.075 0.038 0.037 0.000 0.000 0.000 0.000 271.4 7.01 0.157 0.091 0.066 0.000 0.000 0.000 0.000 334.1 7.01 0.093 0.093 0.000 0.000 0.000 0.000 0.000 12.5 7.18 0.380 0.001 0.029 0.142 0.144 0.057 0.007 36.0 7.19 0.865 0.018 0.134 0.337 0.320 0.055 0.001 64.0 7.18 0.803 0.029 0.182 0.445 0.148 0.000 0.000 89.1 7.19 0.497 0.024 0.152 0.308 0.014 0.000 0.000 121.8 7.19 0.739 0.040 0.252 0.447 0.001 0.000 0.000 130.3 7.18 0.196 0.020 0.119 0.057 0.000 0.000 0.000 167.6 7.21 0.232 0.024 0.131 0.077 0.000 0.000 0.000 176.4 7.17 0.279 0.036 0.173 0.070 0.000 0.000 0.000 207.4 7.20 0.059 0.013 0.042 0.004 0.000 0.000 0.000 227.2 7.19 0.221 0.053 0.168 0.000 0.000 0.000 0.000 259.4 7.19 0.069 0.021 0.048 0.000 0.000 0.000 0.000 282.0 7.19 0.097 0.047 0.050 0.000 0.000 0.000 0.000 316.3 7.19 0.069 0.049 0.019 0.000 0.000 0.000 0.000 361.4 7.19 0.076 0.076 0.000 0.000 0.000 0.000 0.000 12.0 7.39 0.557 0.001 0.032 0.211 0.216 0.086 0.012 36.0 7.39 1.208 0.021 0.180 0.454 0.448 0.103 0.002 63.8 7.39 1.104 0.034 0.219 0.550 0.300 0.001 0.000 89.1 7.38 0.731 0.030 0.188 0.444 0.070 0.000 0.000 116.1 7.42 0.523 0.021 0.131 0.329 0.043 0.000 0.000 128.6 7.37 0.899 0.052 0.332 0.514 0.000 0.000 0.000 167.3 7.40 0.518 0.043 0.228 0.246 0.000 0.000 0.000 181.3 7.37 0.343 0.033 0.193 0.117 0.000 0.000 0.000 219.2 7.41 0.401 0.062 0.261 0.078 0.000 0.000 0.000 234.9 7.36 0.137 0.031 0.107 0.000 0.000 0.000 0.000

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\Deaggregation.txt 3/3/2008 Page 7 of 7 271.5 7.40 0.314 0.084 0.230 0.000 0.000 0.000 0.000 335.8 7.39 0.232 0.133 0.099 0.000 0.000 0.000 0.000 391.4 7.38 0.104 0.104 0.000 0.000 0.000 0.000 0.000 Summary statistics for above 0.2s PSA deaggregation, R=distance, e=epsilon: Mean src-site R= 58.0 km; M= 6.00; eps0= 0.24. Mean calculated for all so Modal src-site R= 14.2 km; M= 4.80; eps0= 0.26 from peak (R,M) bin Gridded source distance metrics: Rseis Rrup and Rjb MODE R*= 17.0km; M*= 4.80; EPS.INTERVAL: 1 to 2 sigma % CONTRIB.= 2.804 Principal sources (faults, subduction, random seismicity having >10% contribut Source Category: % contr. R(km) M epsilon0 (mean values) CEUS gridded seism. 100.00 58.0 6.00 0.24 Individual fault hazard details if contrib.>1%: ********************Central or Eastern U.S. Site *****************************

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\Deaggregation.txt

B-4 Pseudo-Static Slope Stability Analysis to Determine Yield Acceleration

N:\projects\119504\2008\VF FEP Docs\Global Stability

Analysis Run Date: 2/25/2008 Time of Run: 09:31AM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Global-Stabil\ Output Filename: C:\GEOTECHNICAL\saugus\2008\Global-Stabil\ Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Glob••••tabil\

PROBLEM DESCRIPTION: RESCO; Ash at 3H:1V to El. 50'; With 100 % Consolid; Y-Accel; Run#Y1-Bc-2

BOUNDARY COORDINATES 5 Top Boundaries 24 Total Boundaries

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 2 of 11 23 240.00 90.00 600.00 90.00 19 24 0.00 60.00 600.00 60.00 20 Default Y-Origin = 0.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) 1

ISOTROPIC SOIL PARAMETERS

20 Type(s) of Soil

Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 100.0 100.0 0.0 40.0 0.00 0.0 1 2 75.0 75.0 0.0 28.0 0.00 0.0 1 3 100.0 100.0 1000.0 0.0 0.00 0.0 1 4 120.0 120.0 0.0 30.0 0.00 0.0 1 5 108.0 108.0 758.0 0.0 0.00 0.0 1 6 108.0 108.0 789.0 0.0 0.00 0.0 1 7 108.0 108.0 875.0 0.0 0.00 0.0 1 8 108.0 108.0 947.0 0.0 0.00 0.0 1 9 108.0 108.0 1052.0 0.0 0.00 0.0 1 10 108.0 108.0 895.0 0.0 0.00 0.0 1 11 108.0 108.0 918.0 0.0 0.00 0.0 1 12 108.0 108.0 987.0 0.0 0.00 0.0 1 13 108.0 108.0 1130.0 0.0 0.00 0.0 1 14 108.0 108.0 1270.0 0.0 0.00 0.0 1 15 108.0 108.0 879.0 0.0 0.00 0.0 1 16 108.0 108.0 912.0 0.0 0.00 0.0 1 17 108.0 108.0 1144.0 0.0 0.00 0.0 1 18 108.0 108.0 1404.0 0.0 0.00 0.0 1 19 108.0 108.0 1544.0 0.0 0.00 0.0 1 20 130.0 130.0 0.0 34.0 0.00 0.0 1 1

1 PIEZOMETRIC SURFACE(S) SPECIFIED

Unit Weight of Water = 62.40 (pcf)

Piezometric Surface No. 1 Specified by 2 Coordinate Points Pore Pressure Inclination Factor = 0.50

Point X-Water Y-Water No. (ft) (ft) 1 0.00 153.00 2 600.00 154.00 Specified Peak Ground Acceleration Coefficient (A) = 0.186(g) Specified Horizontal Earthquake Coefficient (kh) = 0.093(g) Specified Vertical Earthquake Coefficient (kv) = 0.000(g) Specified Seismic Pore-Pressure Factor = 0.000 1

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 3 of 11

A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified.

3600 Trial Surfaces Have Been Generated.

60 Surface(s) Initiate(s) From Each Of 60 Points Equally Spaced Along The Ground Surface Between X = 0.00(ft) and X = 150.00(ft)

Each Surface Terminates Between X = 200.00(ft) and X = 400.00(ft)

Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = 0.00(ft)

15.00(ft) Line Segments Define Each Trial Failure Surface.

Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First.

* * Safety Factors Are Calculated By The Modified Bishop Method * *

Total Number of Trial Surfaces Evaluated = 3600 Statistical Data On All Valid FS Values: FS Max = 4.046 FS Min = 1.004 FS Ave = 1.694 Standard Deviation = 0.466 Coefficient of Variation = 27.5

Failure Surface Specified By 29 Coordinate Points

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 4 of 11 20 264.47 113.65 21 277.65 120.81 22 290.32 128.84 23 302.42 137.70 24 313.90 147.36 25 324.70 157.77 26 334.77 168.88 27 344.08 180.65 28 352.57 193.01 29 356.16 199.07 Circle Center At X = 164.74 ; Y = 312.95 ; and Radius = 222.86

Factor of Safety *** 1.004 ***

Individual data on the 44 slices

Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 7.1 1979.8 0.0 0.0 0. 0. 184.1 0.0 2 3.0 2042.8 0.0 403.7 0. 0. 190.0 0.0 3 0.5 375.8 0.0 132.0 0. 0. 34.9 0.0 4 7.5 8876.1 0.0 4211.7 0. 0. 825.5 0.0 5 3.8 6505.1 0.0 3652.2 0. 0. 605.0 0.0 6 2.3 4611.3 0.0 2522.9 0. 0. 428.9 0.0 7 9.7 24668.4 0.0 14187.2 0. 0. 2294.2 0.0 8 12.6 42899.6 0.0 24803.5 0. 0. 3989.7 0.0 9 4.4 17631.7 0.0 9998.3 0. 0. 1639.7 0.0 10 8.7 38572.2 0.0 22109.2 0. 0. 3587.2 0.0 11 13.5 68859.0 0.0 38589.0 0. 0. 6403.9 0.0 12 13.9 80532.9 0.0 44218.6 0. 0. 7489.6 0.0 13 14.3 90924.9 0.0 48970.9 0. 0. 8456.0 0.0 14 14.6 99771.3 0.0 52824.3 0. 0. 9278.7 0.0 15 1.5 10970.5 0.0 5727.9 0. 0. 1020.3 0.0 16 13.2 96700.2 0.0 50033.4 0. 0. 8993.1 0.0 17 14.9 114880.7 0.0 57768.7 0. 0. 10683.9 0.0 18 1.9 14743.3 0.0 7293.6 0. 0. 1371.1 0.0 19 10.0 81048.2 0.0 39241.1 0. 0. 7537.5 0.0 20 3.1 26070.5 0.0 12302.7 0. 0. 2424.6 0.0 21 15.0 129554.0 0.0 58962.4 0. 0. 12048.5 0.0 22 14.9 135028.1 0.0 58143.4 0. 0. 12557.6 0.0 23 6.9 64421.3 0.0 26743.7 0. 0. 5991.2 0.0 24 7.9 73740.4 0.0 29640.1 0. 0. 6857.9 0.0 25 14.6 138925.2 0.0 53691.9 0. 0. 12920.0 0.0 26 14.3 137346.0 0.0 50079.6 0. 0. 12773.2 0.0 27 3.2 30450.5 0.0 10782.4 0. 0. 2831.9 0.0 28 10.8 101053.1 0.0 34781.1 0. 0. 9397.9 0.0 29 13.6 119336.0 0.0 40163.9 0. 0. 11098.2 0.0 30 11.7 94275.8 0.0 30412.4 0. 0. 8767.6 0.0 31 1.5 11413.5 0.0 3492.9 0. 0. 1061.5 0.0 32 12.7 91064.1 0.0 26816.1 0. 0. 8469.0 0.0 33 12.1 75815.2 0.0 18928.3 0. 0. 7050.8 0.0 34 0.4 2029.4 0.0 449.3 0. 0. 188.7 0.0 35 5.9 32363.4 0.0 6303.7 0. 0. 3009.8 0.0 36 5.2 25527.9 0.0 3524.8 0. 0. 2374.1 0.0 37 2.7 12512.2 0.0 1148.9 0. 0. 1163.6 0.0 38 3.7 15785.1 0.0 560.5 0. 0. 1468.0 0.0 39 4.4 17632.1 0.0 0.0 0. 0. 1639.8 0.0 40 10.1 34548.0 0.0 0.0 0. 0. 3213.0 0.0

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 5 of 11 41 0.9 2620.5 0.0 0.0 0. 0. 243.7 0.0 42 8.4 20110.3 0.0 0.0 0. 0. 1870.3 0.0 43 8.5 10450.5 0.0 0.0 0. 0. 971.9 0.0 44 3.6 1092.3 0.0 0.0 0. 0. 101.6 0.0 Failure Surface Specified By 29 Coordinate Points

Factor of Safety *** 1.009 ***

1 Failure Surface Specified By 30 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 5.08 160.21 2 16.03 149.95 3 27.60 140.41 4 39.76 131.63 5 52.45 123.63 6 65.62 116.45 7 79.22 110.12 8 93.20 104.67 9 107.49 100.12 10 122.04 96.49 11 136.80 93.78

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 6 of 11 12 151.69 92.02 13 166.67 91.21 14 181.67 91.35 15 196.63 92.44 16 211.49 94.48 17 226.19 97.45 18 240.68 101.36 19 254.88 106.18 20 268.75 111.88 21 282.23 118.46 22 295.27 125.88 23 307.81 134.11 24 319.80 143.12 25 331.20 152.88 26 341.95 163.34 27 352.02 174.46 28 361.36 186.19 29 369.93 198.50 30 370.21 198.96 Circle Center At X = 171.97 ; Y = 327.31 ; and Radius = 236.16

Factor of Safety *** 1.010 ***

Failure Surface Specified By 30 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 11.07 149.88 3 22.73 140.44 4 34.94 131.72 5 47.64 123.75 6 60.81 116.57 7 74.38 110.18 8 88.32 104.63 9 102.56 99.93 10 117.06 96.09 11 131.77 93.13 12 146.62 91.06 13 161.58 89.89 14 176.58 89.62 15 191.56 90.26 16 206.48 91.79 17 221.28 94.23 18 235.91 97.55 19 250.31 101.74 20 264.44 106.79 21 278.23 112.69 22 291.64 119.40 23 304.63 126.91 24 317.14 135.19 25 329.13 144.20 26 340.55 153.92 27 351.37 164.31 28 361.54 175.34 29 371.03 186.95 30 379.64 198.88 Circle Center At X = 173.51 ; Y = 338.64 ; and Radius = 249.04

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 7 of 11

Factor of Safety *** 1.011 ***

1 Failure Surface Specified By 31 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 7.63 160.32 2 18.87 150.38 3 30.66 141.12 4 42.97 132.54 5 55.75 124.69 6 68.97 117.60 7 82.57 111.27 8 96.51 105.75 9 110.75 101.03 10 125.24 97.15 11 139.93 94.11 12 154.77 91.92 13 169.71 90.59 14 184.70 90.13 15 199.70 90.53 16 214.65 91.79 17 229.49 93.92 18 244.19 96.90 19 258.70 100.72 20 272.96 105.38 21 286.93 110.85 22 300.55 117.11 23 313.80 124.16 24 326.61 131.95 25 338.96 140.47 26 350.79 149.69 27 362.07 159.58 28 372.76 170.10 29 382.83 181.22 30 392.24 192.90 31 396.41 198.75 Circle Center At X = 185.25 ; Y = 349.95 ; and Radius = 259.83

Factor of Safety *** 1.012 ***

Failure Surface Specified By 28 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 5.08 160.21 2 15.71 149.63 3 27.04 139.80 4 39.02 130.77 5 51.59 122.59 6 64.70 115.29 7 78.28 108.92

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 8 of 11 8 92.26 103.49 9 106.59 99.05 10 121.19 95.59 11 135.99 93.16 12 150.92 91.74 13 165.92 91.36 14 180.90 92.01 15 195.81 93.69 16 210.56 96.40 17 225.09 100.11 18 239.34 104.82 19 253.22 110.49 20 266.68 117.11 21 279.66 124.64 22 292.08 133.05 23 303.90 142.29 24 315.05 152.32 25 325.48 163.10 26 335.15 174.57 27 344.00 186.67 28 351.84 199.11 Circle Center At X = 163.95 ; Y = 309.04 ; and Radius = 217.69

Factor of Safety *** 1.012 ***

1 Failure Surface Specified By 31 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 2.54 160.11 2 13.69 150.07 3 25.41 140.70 4 37.66 132.05 5 50.40 124.13 6 63.58 116.98 7 77.16 110.61 8 91.10 105.06 9 105.34 100.35 10 119.83 96.48 11 134.53 93.47 12 149.37 91.33 13 164.32 90.08 14 179.32 89.71 15 194.31 90.22 16 209.24 91.62 17 224.07 93.90 18 238.74 97.05 19 253.19 101.05 20 267.38 105.91 21 281.26 111.59 22 294.79 118.08 23 307.90 125.36 24 320.57 133.40 25 332.73 142.17 26 344.36 151.65 27 355.41 161.80 28 365.84 172.57 29 375.62 183.95 30 384.71 195.88

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 9 of 11 31 386.68 198.83 Circle Center At X = 178.10 ; Y = 343.80 ; and Radius = 254.10

Factor of Safety *** 1.012 ***

Failure Surface Specified By 31 Coordinate Points

Factor of Safety *** 1.013 ***

1 Failure Surface Specified By 29 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 10.95 149.74 3 22.54 140.23

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 10 of 11 4 34.73 131.49 5 47.47 123.56 6 60.70 116.49 7 74.36 110.30 8 88.40 105.02 9 102.75 100.66 10 117.36 97.26 11 132.16 94.81 12 147.09 93.35 13 162.08 92.86 14 177.07 93.35 15 192.00 94.82 16 206.80 97.27 17 221.41 100.68 18 235.76 105.04 19 249.79 110.33 20 263.46 116.52 21 276.68 123.60 22 289.42 131.52 23 301.61 140.27 24 313.20 149.79 25 324.14 160.05 26 334.39 171.00 27 343.90 182.60 28 352.63 194.80 29 355.28 199.08 Circle Center At X = 162.05 ; Y = 321.97 ; and Radius = 229.12

Factor of Safety *** 1.014 ***

Failure Surface Specified By 30 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 15.25 160.64 2 26.15 150.32 3 37.67 140.72 4 49.78 131.87 5 62.43 123.81 6 75.56 116.56 7 89.13 110.15 8 103.07 104.62 9 117.33 99.99 10 131.87 96.26 11 146.60 93.47 12 161.49 91.61 13 176.46 90.70 14 191.46 90.74 15 206.43 91.74 16 221.30 93.67 17 236.02 96.55 18 250.53 100.35 19 264.77 105.07 20 278.69 110.67 21 292.22 117.15 22 305.31 124.47 23 317.91 132.61 24 329.97 141.53 25 341.44 151.19 26 352.28 161.56

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT 2/25/2008 Page 11 of 11 27 362.44 172.60 28 371.88 184.26 29 380.56 196.49 30 382.02 198.86 Circle Center At X = 183.27 ; Y = 327.16 ; and Radius = 236.56

Factor of Safety *** 1.015 ***

**** END OF GSTABL7 OUTPUT ****

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-2.OUT

PROBLEM DESCRIPTION: RESCO; Ash at 3H:1V to El. 50'; With 100 % Consolid; Y-Accel; Run#Y1-Bc-r2

BOUNDARY COORDINATES 5 Top Boundaries 24 Total Boundaries

Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 160.00 220.00 165.00 2 2 220.00 165.00 250.00 170.00 2 3 250.00 170.00 340.00 200.00 1 4 340.00 200.00 590.00 198.00 1 5 590.00 198.00 700.00 197.00 1 6 250.00 170.00 700.00 170.00 2 7 0.00 150.00 700.00 150.00 3 8 0.00 143.00 700.00 143.00 4 9 0.00 138.00 220.00 138.00 5 10 220.00 138.00 260.00 138.00 6 11 260.00 138.00 300.00 138.00 7 12 300.00 138.00 340.00 138.00 8 13 340.00 138.00 700.00 138.00 9 14 0.00 120.00 220.00 120.00 10 15 220.00 120.00 260.00 120.00 11 16 260.00 120.00 300.00 120.00 12 17 300.00 120.00 340.00 120.00 13 18 340.00 120.00 700.00 120.00 14 19 0.00 90.00 220.00 90.00 15 20 220.00 90.00 260.00 90.00 16 21 260.00 90.00 300.00 90.00 17 22 300.00 90.00 340.00 90.00 18

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 2 of 12 23 340.00 90.00 700.00 90.00 19 24 0.00 60.00 700.00 60.00 20 Default Y-Origin = 0.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) 1

ISOTROPIC SOIL PARAMETERS

20 Type(s) of Soil

Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 100.0 100.0 0.0 40.0 0.00 0.0 1 2 75.0 75.0 0.0 28.0 0.00 0.0 1 3 100.0 100.0 1000.0 0.0 0.00 0.0 1 4 120.0 120.0 0.0 30.0 0.00 0.0 1 5 108.0 108.0 758.0 0.0 0.00 0.0 1 6 108.0 108.0 789.0 0.0 0.00 0.0 1 7 108.0 108.0 875.0 0.0 0.00 0.0 1 8 108.0 108.0 947.0 0.0 0.00 0.0 1 9 108.0 108.0 1052.0 0.0 0.00 0.0 1 10 108.0 108.0 895.0 0.0 0.00 0.0 1 11 108.0 108.0 918.0 0.0 0.00 0.0 1 12 108.0 108.0 987.0 0.0 0.00 0.0 1 13 108.0 108.0 1130.0 0.0 0.00 0.0 1 14 108.0 108.0 1270.0 0.0 0.00 0.0 1 15 108.0 108.0 879.0 0.0 0.00 0.0 1 16 108.0 108.0 912.0 0.0 0.00 0.0 1 17 108.0 108.0 1144.0 0.0 0.00 0.0 1 18 108.0 108.0 1404.0 0.0 0.00 0.0 1 19 108.0 108.0 1544.0 0.0 0.00 0.0 1 20 130.0 130.0 0.0 34.0 0.00 0.0 1 1

1 PIEZOMETRIC SURFACE(S) SPECIFIED

Unit Weight of Water = 62.40 (pcf)

Piezometric Surface No. 1 Specified by 2 Coordinate Points Pore Pressure Inclination Factor = 0.50

Point X-Water Y-Water No. (ft) (ft) 1 0.00 153.00 2 700.00 154.00 Specified Peak Ground Acceleration Coefficient (A) = 0.162(g) Specified Horizontal Earthquake Coefficient (kh) = 0.081(g) Specified Vertical Earthquake Coefficient (kv) = 0.000(g) Specified Seismic Pore-Pressure Factor = 0.000 1

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 3 of 12

A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified.

3600 Trial Surfaces Have Been Generated.

60 Surface(s) Initiate(s) From Each Of 60 Points Equally Spaced Along The Ground Surface Between X = 0.00(ft) and X = 250.00(ft)

Each Surface Terminates Between X = 300.00(ft) and X = 600.00(ft)

Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = 0.00(ft)

15.00(ft) Line Segments Define Each Trial Failure Surface.

Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First.

* * Safety Factors Are Calculated By The Modified Bishop Method * *

Total Number of Trial Surfaces Evaluated = 3600 Statistical Data On All Valid FS Values: FS Max = 5.188 FS Min = 1.000 FS Ave = 1.768 Standard Deviation = 0.625 Coefficient of Variation = 35.3

Failure Surface Specified By 41 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 11.00 149.80 3 22.43 140.09 4 34.26 130.86 5 46.47 122.15 6 59.04 113.97 7 71.95 106.33 8 85.17 99.24 9 98.68 92.73 10 112.46 86.79 11 126.47 81.45 12 140.70 76.71 13 155.12 72.58 14 169.71 69.07 15 184.43 66.18 16 199.25 63.92 17 214.17 62.29 18 229.13 61.30 19 244.13 60.94

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 4 of 12 20 259.13 61.23 21 274.10 62.15 22 289.02 63.71 23 303.86 65.91 24 318.59 68.73 25 333.19 72.18 26 347.62 76.25 27 361.88 80.92 28 375.92 86.20 29 389.72 92.07 30 403.26 98.53 31 416.51 105.55 32 429.45 113.14 33 442.06 121.26 34 454.31 129.92 35 466.18 139.09 36 477.65 148.76 37 488.70 158.90 38 499.31 169.51 39 509.45 180.56 40 519.12 192.03 41 524.13 198.53 Circle Center At X = 244.92 ; Y = 413.26 ; and Radius = 352.32

Factor of Safety *** 1.000 ***

Individual data on the 58 slices

Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 7.5 2025.2 0.0 0.0 0. 0. 164.0 0.0 2 3.2 2120.6 0.0 416.7 0. 0. 171.8 0.0 3 0.2 164.4 0.0 55.9 0. 0. 13.3 0.0 4 8.0 9083.1 0.0 4338.0 0. 0. 735.7 0.0 5 3.4 5687.6 0.0 3223.7 0. 0. 460.7 0.0 6 2.7 5258.7 0.0 2962.0 0. 0. 426.0 0.0 7 9.2 22756.1 0.0 13479.6 0. 0. 1843.2 0.0 8 12.2 41029.9 0.0 24850.8 0. 0. 3323.4 0.0 9 3.3 13090.9 0.0 7875.0 0. 0. 1060.4 0.0 10 9.3 40881.8 0.0 24899.0 0. 0. 3311.4 0.0 11 12.9 66729.7 0.0 40196.8 0. 0. 5405.1 0.0 12 13.2 79158.4 0.0 47105.8 0. 0. 6411.8 0.0 13 13.5 91122.4 0.0 53488.3 0. 0. 7380.9 0.0 14 6.3 45977.9 0.0 26582.7 0. 0. 3724.2 0.0 15 7.4 56514.1 0.0 32750.3 0. 0. 4577.6 0.0 16 14.0 113145.6 0.0 64629.1 0. 0. 9164.8 0.0 17 14.2 122970.4 0.0 69367.1 0. 0. 9960.6 0.0 18 14.4 131863.3 0.0 73538.4 0. 0. 10680.9 0.0 19 14.6 139732.1 0.0 77135.4 0. 0. 11318.3 0.0 20 14.7 146495.4 0.0 80151.6 0. 0. 11866.1 0.0 21 14.8 152084.0 0.0 82581.5 0. 0. 12318.8 0.0 22 14.9 156441.2 0.0 84420.8 0. 0. 12671.7 0.0 23 5.8 61939.5 0.0 33276.3 0. 0. 5017.1 0.0 24 9.1 98034.1 0.0 52389.7 0. 0. 7940.8 0.0 25 15.0 163992.0 0.0 86315.1 0. 0. 13283.4 0.0 26 5.9 65041.0 0.0 33836.7 0. 0. 5268.3 0.0 27 9.1 102700.3 0.0 52530.0 0. 0. 8318.7 0.0 28 0.9 9960.9 0.0 5028.8 0. 0. 806.8 0.0

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 5 of 12 29 14.1 163634.0 0.0 80791.9 0. 0. 13254.4 0.0 30 14.9 178412.6 0.0 84678.1 0. 0. 14451.4 0.0 31 11.0 134199.9 0.0 61585.5 0. 0. 10870.2 0.0 32 3.9 47608.2 0.0 21355.7 0. 0. 3856.3 0.0 33 14.7 183768.2 0.0 80612.8 0. 0. 14885.2 0.0 34 14.6 184294.7 0.0 77697.3 0. 0. 14927.9 0.0 35 6.8 86481.2 0.0 35490.5 0. 0. 7005.0 0.0 36 7.6 95930.6 0.0 38709.8 0. 0. 7770.4 0.0 37 14.3 173949.2 0.0 70127.4 0. 0. 14089.9 0.0 38 14.0 163653.9 0.0 65486.6 0. 0. 13256.0 0.0 39 8.9 99587.0 0.0 39612.6 0. 0. 8066.5 0.0 40 4.9 52833.3 0.0 20673.5 0. 0. 4279.5 0.0 41 13.5 140360.8 0.0 54535.4 0. 0. 11369.2 0.0 42 13.3 127596.4 0.0 48244.8 0. 0. 10335.3 0.0 43 12.9 114256.8 0.0 41425.8 0. 0. 9254.8 0.0 44 10.6 85584.1 0.0 29286.1 0. 0. 6932.3 0.0 45 2.0 14895.4 0.0 4804.6 0. 0. 1206.5 0.0 46 12.3 86407.5 0.0 26252.9 0. 0. 6999.0 0.0 47 10.5 64228.1 0.0 16243.9 0. 0. 5202.5 0.0 48 1.4 7951.5 0.0 1682.5 0. 0. 644.1 0.0 49 4.6 24734.4 0.0 4779.2 0. 0. 2003.5 0.0 50 6.8 32819.7 0.0 4347.4 0. 0. 2658.4 0.0 51 1.4 6025.2 0.0 493.7 0. 0. 488.0 0.0 52 4.0 17071.5 0.0 627.1 0. 0. 1382.8 0.0 53 5.7 22200.6 0.0 0.0 0. 0. 1798.2 0.0 54 10.6 35119.2 0.0 0.0 0. 0. 2844.7 0.0 55 0.4 1299.4 0.0 0.0 0. 0. 105.2 0.0 56 9.7 22690.3 0.0 0.0 0. 0. 1837.9 0.0 57 9.7 11898.6 0.0 0.0 0. 0. 963.8 0.0 58 5.0 1639.7 0.0 0.0 0. 0. 132.8 0.0 Failure Surface Specified By 39 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 8.47 160.19 2 19.09 149.59 3 30.18 139.49 4 41.73 129.93 5 53.72 120.91 6 66.11 112.46 7 78.88 104.59 8 92.01 97.34 9 105.46 90.70 10 119.21 84.69 11 133.22 79.33 12 147.46 74.63 13 161.91 70.61 14 176.53 67.25 15 191.29 64.59 16 206.16 62.61 17 221.11 61.33 18 236.10 60.75 19 251.10 60.87 20 266.07 61.69 21 281.00 63.20 22 295.83 65.41 23 310.55 68.31 24 325.12 71.89 25 339.50 76.15 26 353.67 81.07 27 367.60 86.64 28 381.24 92.87 29 394.59 99.72 30 407.60 107.18 31 420.25 115.24

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 6 of 12 32 432.51 123.89 33 444.35 133.09 34 455.75 142.84 35 466.68 153.11 36 477.13 163.88 37 487.06 175.12 38 496.45 186.82 39 505.10 198.68 Circle Center At X = 241.07 ; Y = 382.37 ; and Radius = 321.65

Factor of Safety *** 1.000 ***

1 Failure Surface Specified By 39 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 8.47 160.19 2 19.20 149.71 3 30.41 139.74 4 42.07 130.30 5 54.15 121.41 6 66.64 113.10 7 79.50 105.38 8 92.71 98.27 9 106.23 91.78 10 120.04 85.92 11 134.11 80.72 12 148.40 76.18 13 162.90 72.31 14 177.55 69.12 15 192.34 66.61 16 207.23 64.80 17 222.19 63.68 18 237.18 63.26 19 252.18 63.54 20 267.15 64.52 21 282.06 66.19 22 296.87 68.56 23 311.55 71.62 24 326.08 75.35 25 340.42 79.76 26 354.53 84.83 27 368.40 90.56 28 381.98 96.92 29 395.25 103.91 30 408.18 111.52 31 420.75 119.71 32 432.91 128.48 33 444.66 137.81 34 455.96 147.68 35 466.78 158.06 36 477.11 168.94 37 486.93 180.28 38 496.20 192.07 39 500.94 198.71 Circle Center At X = 238.68 ; Y = 385.07 ; and Radius = 321.81

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 7 of 12 Factor of Safety *** 1.006 ***

Failure Surface Specified By 39 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 12.71 160.29 2 23.34 149.70 3 34.45 139.63 4 46.04 130.10 5 58.06 121.13 6 70.49 112.73 7 83.31 104.94 8 96.48 97.76 9 109.97 91.22 10 123.77 85.32 11 137.82 80.09 12 152.11 75.52 13 166.60 71.64 14 181.26 68.46 15 196.05 65.97 16 210.94 64.18 17 225.91 63.10 18 240.90 62.74 19 255.90 63.08 20 270.86 64.14 21 285.76 65.90 22 300.55 68.37 23 315.21 71.54 24 329.71 75.40 25 344.00 79.94 26 358.07 85.16 27 371.87 91.04 28 385.37 97.56 29 398.56 104.72 30 411.38 112.50 31 423.83 120.87 32 435.86 129.83 33 447.46 139.34 34 458.59 149.40 35 469.23 159.97 36 479.35 171.04 37 488.94 182.57 38 497.98 194.54 39 500.82 198.71 Circle Center At X = 241.12 ; Y = 378.91 ; and Radius = 316.18

Factor of Safety *** 1.006 ***

1 Failure Surface Specified By 40 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft)

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 8 of 12 1 21.19 160.48 2 31.84 149.92 3 42.96 139.86 4 54.54 130.32 5 66.54 121.32 6 78.95 112.89 7 91.72 105.03 8 104.85 97.77 9 118.29 91.12 10 132.03 85.10 11 146.03 79.71 12 160.26 74.97 13 174.70 70.89 14 189.30 67.48 15 204.05 64.74 16 218.91 62.69 17 233.85 61.32 18 248.83 60.63 19 263.83 60.64 20 278.82 61.34 21 293.75 62.72 22 308.61 64.79 23 323.36 67.54 24 337.96 70.96 25 352.39 75.05 26 366.62 79.80 27 380.61 85.20 28 394.34 91.24 29 407.78 97.90 30 420.90 105.17 31 433.67 113.04 32 446.07 121.49 33 458.07 130.49 34 469.63 140.04 35 480.75 150.11 36 491.39 160.68 37 501.54 171.73 38 511.17 183.23 39 520.25 195.17 40 522.59 198.54 Circle Center At X = 256.16 ; Y = 386.75 ; and Radius = 326.20

Factor of Safety *** 1.007 ***

Failure Surface Specified By 42 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 11.24 150.07 3 22.87 140.60 4 34.88 131.61 5 47.24 123.11 6 59.94 115.12 7 72.95 107.66 8 86.25 100.72 9 99.82 94.33 10 113.64 88.49 11 127.68 83.22 12 141.93 78.52

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 9 of 12 13 156.35 74.40 14 170.93 70.87 15 185.64 67.94 16 200.45 65.60 17 215.35 63.86 18 230.31 62.72 19 245.30 62.20 20 260.30 62.28 21 275.28 62.97 22 290.23 64.26 23 305.11 66.16 24 319.90 68.66 25 334.57 71.75 26 349.11 75.44 27 363.49 79.71 28 377.69 84.57 29 391.67 89.99 30 405.43 95.97 31 418.93 102.51 32 432.15 109.59 33 445.08 117.20 34 457.69 125.32 35 469.96 133.95 36 481.87 143.07 37 493.40 152.66 38 504.53 162.71 39 515.25 173.21 40 525.53 184.13 41 535.37 195.46 42 537.73 198.42 Circle Center At X = 250.78 ; Y = 432.44 ; and Radius = 370.29

Factor of Safety *** 1.008 ***

1 Failure Surface Specified By 39 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 12.71 160.29 2 23.39 149.75 3 34.55 139.73 4 46.17 130.25 5 58.24 121.34 6 70.71 113.00 7 83.57 105.27 8 96.77 98.17 9 110.30 91.69 10 124.13 85.87 11 138.21 80.71 12 152.53 76.22 13 167.04 72.42 14 181.71 69.32 15 196.52 66.91 16 211.42 65.21 17 226.39 64.22 18 241.39 63.95 19 256.38 64.39 20 271.34 65.54 21 286.22 67.39

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 10 of 12 22 301.00 69.96 23 315.64 73.22 24 330.11 77.18 25 344.37 81.82 26 358.40 87.13 27 372.16 93.10 28 385.62 99.72 29 398.75 106.97 30 411.52 114.84 31 423.91 123.30 32 435.87 132.35 33 447.40 141.95 34 458.45 152.09 35 469.01 162.74 36 479.05 173.89 37 488.55 185.49 38 497.49 197.54 39 498.29 198.73 Circle Center At X = 239.69 ; Y = 379.48 ; and Radius = 315.54

Factor of Safety *** 1.010 ***

Failure Surface Specified By 41 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 0.00 160.00 2 11.26 150.08 3 22.91 140.64 4 34.94 131.69 5 47.34 123.24 6 60.07 115.30 7 73.11 107.90 8 86.46 101.05 9 100.07 94.74 10 113.93 89.01 11 128.01 83.85 12 142.30 79.28 13 156.76 75.30 14 171.38 71.92 15 186.12 69.14 16 200.96 66.98 17 215.88 65.43 18 230.85 64.49 19 245.85 64.18 20 260.84 64.48 21 275.82 65.40 22 290.74 66.94 23 305.58 69.09 24 320.33 71.85 25 334.94 75.22 26 349.41 79.18 27 363.70 83.74 28 377.79 88.89 29 391.66 94.61 30 405.27 100.89 31 418.62 107.74 32 431.68 115.13 33 444.41 123.05 34 456.82 131.49

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 11 of 12 35 468.86 140.43 36 480.52 149.86 37 491.79 159.77 38 502.63 170.13 39 513.04 180.93 40 523.00 192.15 41 528.18 198.49 Circle Center At X = 246.02 ; Y = 427.91 ; and Radius = 363.73

Factor of Safety *** 1.011 ***

1 Failure Surface Specified By 40 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 12.71 160.29 2 23.74 150.12 3 35.19 140.43 4 47.05 131.25 5 59.30 122.59 6 71.91 114.47 7 84.86 106.90 8 98.13 99.90 9 111.68 93.47 10 125.50 87.64 11 139.56 82.42 12 153.83 77.80 13 168.29 73.81 14 182.91 70.44 15 197.66 67.71 16 212.51 65.62 17 227.44 64.17 18 242.42 63.38 19 257.42 63.22 20 272.41 63.72 21 287.37 64.87 22 302.26 66.66 23 317.06 69.09 24 331.75 72.16 25 346.28 75.86 26 360.64 80.19 27 374.81 85.13 28 388.74 90.68 29 402.42 96.83 30 415.83 103.56 31 428.93 110.87 32 441.70 118.74 33 454.12 127.15 34 466.16 136.09 35 477.81 145.54 36 489.04 155.49 37 499.82 165.91 38 510.15 176.79 39 520.00 188.11 40 528.27 198.49 Circle Center At X = 253.40 ; Y = 410.08 ; and Radius = 346.88

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT 2/25/2008 Page 12 of 12 Factor of Safety *** 1.012 ***

Failure Surface Specified By 38 Coordinate Points

Point X-Surf Y-Surf No. (ft) (ft) 1 21.19 160.48 2 31.80 149.88 3 42.91 139.80 4 54.50 130.28 5 66.54 121.34 6 79.00 112.99 7 91.86 105.26 8 105.08 98.17 9 118.62 91.73 10 132.47 85.95 11 146.58 80.86 12 160.92 76.47 13 175.46 72.77 14 190.16 69.79 15 204.99 67.53 16 219.91 66.00 17 234.89 65.19 18 249.89 65.12 19 264.87 65.78 20 279.81 67.16 21 294.66 69.28 22 309.39 72.11 23 323.96 75.66 24 338.34 79.92 25 352.50 84.87 26 366.40 90.51 27 380.01 96.81 28 393.30 103.78 29 406.23 111.38 30 418.78 119.60 31 430.90 128.43 32 442.59 137.83 33 453.80 147.80 34 464.51 158.30 35 474.70 169.31 36 484.34 180.80 37 493.41 192.75 38 497.51 198.74 Circle Center At X = 243.85 ; Y = 372.56 ; and Radius = 307.50

Factor of Safety *** 1.015 ***

**** END OF GSTABL7 OUTPUT ****

C:\GEOTECHNICAL\saugus\2008\Global-Stabil\y1-bc-r2.OUT

B-5 Permanent Displacement Calculations

N:\projects\119504\2008\VF FEP Docs\Global Stability

Estimation of Seismically-Induced Permanent Displacement Seismic Slope Stability of Cross Section Across Phase III Saugus RESCO Landfill

Based on USGS (2002) seismic hazard mapping, the peak ground acceleration (PGA) having a10% probability of exceedance in 250 years (this is equivalent to 2% probability in 50 years) = 0.16g

Mean earthquake magnitude (M) = 6.0

Based on pseudo-static slope stability analysis, the yield acceleration (k y) = 0.081g

Conservatively, assume that the maximum acceleration within the critical slope failure surface (averaged spatially) is equal to the PGA; i.e., k max = 0.081g

Therefore, k y/k max = 0.081g/0.16g = 0.50

From the Makdisi and Seed (1978) chart shown below, for an earthquake magnitude of 6 and k y/kmax = 0.5, the likely maximum permanent displacement, (U max ) ≈ 10 cm ≈ 4 inches

Umax ≈ 10 cm

0.5

Attachment C Results of Static and Seismic Slope Stability Analyses Cross-Section Across Phase IV

N:\projects\119504\2008\VF FEP Docs\Global Stability

C-1 Results of Static Slope Stability Analysis

N:\projects\119504\2008\VF FEP Docs\Global Stability

RESCO; Valley Fill Stability; Section A-A'; Short-Term; Static; Circle c:\geotechnical\saugus\2008\revised 2006 stabil\a-stat-bc1.pl2 Run By: nk 3/12/2008 10:04AM 400 # FS Soil Soil Total Saturated Cohesion Friction Piez. a 2.15 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface b 2.16 No. (pcf) (pcf) (psf) (deg) No. c 2.16 New-Ash 1 105.0 105.0 0.0 38.0 W1 d 2.16 Old-Ash 2 105.0 105.0 0.0 38.0 W1 e 2.16 MSW 3 75.0 75.0 0.0 28.0 W1 350 f 2.17 SandSilt 4 120.0 120.0 0.0 32.0 W1 g 2.17 Med-BBC 5 110.0 110.0 1015.0 0.0 W1 h 2.17 Till 6 130.0 130.0 0.0 34.0 W1 i 2.18 SluryWal 7 100.0 100.0 150.0 0.0 W1 j 2.19

300

a j h g i d f e b c 250 1

2 2 2 2 4 7 3 2 2 3 7 200 4 7 4 5 5 5 5 5 6

150

100 0 50 100 150 200 250 300 350 400 450 GSTABL7 v.2 FSmin=2.15 Safety Factors Are Calculated By The Modified Bishop Method C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-bc1.OUT Page 1

*** GSTABL7 *** ** GSTABL7 by Garry H. Gregory, P.E. ** ** Original Version 1.0, January 1996; Current Version 2.003, June 2002 ** (All Rights Reserved-Unauthorized Use Prohibited) ********************************************************************************* SLOPE STABILITY ANALYSIS SYSTEM Modified Bishop, Simplified Janbu, or GLE Method of Slices. (Includes Spencer & Morgenstern-Price Type Analysis) Including Pier/Pile, Reinforcement, Soil Nail, Tieback, Nonlinear Undrained Shear Strength, Curved Phi Envelope, Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces. ********************************************************************************* Analysis Run Date: 3/12/2008 Time of Run: 10:04AM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-bc1.i n Output Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-bc1.O UT Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Revi2006 Stabil\a-stat-bc1.PLT PROBLEM DESCRIPTION: RESCO; Valley Fill Stability; Section A- A'; Short-Term; Static; Circle BOUNDARY COORDINATES 8 Top Boundaries 22 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 214.00 22.00 215.00 4 2 22.00 215.00 25.00 215.00 7 3 25.00 215.00 62.00 215.00 3 4 62.00 215.00 85.00 219.50 2 5 85.00 219.50 100.00 217.80 2 6 100.00 217.80 115.00 220.00 2 7 115.00 220.00 205.00 250.00 1 8 205.00 250.00 450.00 250.00 1 9 115.00 220.00 160.00 217.00 2 10 160.00 217.00 310.00 217.00 2 11 310.00 217.00 450.00 222.00 2 12 62.00 215.00 450.00 215.00 3 13 25.00 215.00 25.01 200.00 7 14 25.01 200.00 450.00 200.00 4 15 25.01 200.00 25.03 190.00 7 16 25.03 190.00 450.00 190.00 5 17 22.00 215.00 22.01 190.00 4 18 0.00 190.00 22.01 190.00 5 19 22.01 190.00 22.03 185.00 5 20 22.03 185.00 25.00 185.00 5 21 25.00 185.00 25.03 190.00 5 22 0.00 174.00 450.00 174.00 6 User Specified Y-Origin = 100.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) ISOTROPIC SOIL PARAMETERS 7 Type(s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 105.0 105.0 0.0 38.0 0.00 0.0 1 2 105.0 105.0 0.0 38.0 0.00 0.0 1 3 75.0 75.0 0.0 28.0 0.00 0.0 1 4 120.0 120.0 0.0 32.0 0.00 0.0 1 5 110.0 110.0 1015.0 0.0 0.00 0.0 1 6 130.0 130.0 0.0 34.0 0.00 0.0 1 7 100.0 100.0 150.0 0.0 0.00 0.0 1 A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified. 1600 Trial Surfaces Have Been Generated. C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-bc1.OUT Page 2

40 Surface(s) Initiate(s) From Each Of 40 Points Equally Spaced Along The Ground Surface Between X = 0.00(ft) and X = 60.00(ft) Each Surface Terminates Between X = 120.00(ft) and X = 400.00(ft) Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = 0.00(ft) 20.00(ft) Line Segments Define Each Trial Failure Surface. Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Modified Bishop Method * * Total Number of Trial Surfaces Evaluated = 1600 Statistical Data On All Valid FS Values: FS Max = 27.268 FS Min = 2.154 FS Ave = 4.761 Standard Deviation = 2.348 Coefficient of Variation = 49.31 % Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 40.00 215.00 2 54.81 201.56 3 71.52 190.57 4 89.73 182.29 5 109.00 176.93 6 128.86 174.62 7 148.85 175.40 8 168.47 179.27 9 187.26 186.13 10 204.76 195.80 11 220.56 208.07 12 234.26 222.63 13 245.55 239.14 14 250.73 250.00 Circle Center At X = 133.65 ; Y = 303.03 ; and Radius = 128.53 Factor of Safety *** 2.154 *** Individual data on the 25 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 14.8 7465.0 0.0 0.0 0. 0. 0.0 0.0 0.0 2 2.4 2525.9 0.0 0.0 0. 0. 0.0 0.0 0.0 3 4.8 6343.7 0.0 0.0 0. 0. 0.0 0.0 0.0 4 9.5 18837.7 0.0 0.0 0. 0. 0.0 0.0 0.0 5 1.2 3119.4 0.0 0.0 0. 0. 0.0 0.0 0.0 6 12.2 36426.3 0.0 0.0 0. 0. 0.0 0.0 0.0 7 4.7 16538.5 0.0 0.0 0. 0. 0.0 0.0 0.0 8 10.3 37858.0 0.0 0.0 0. 0. 0.0 0.0 0.0 9 9.0 35872.5 0.0 0.0 0. 0. 0.0 0.0 0.0 10 6.0 25697.1 0.0 0.0 0. 0. 0.0 0.0 0.0 11 13.9 65085.3 0.0 0.0 0. 0. 0.0 0.0 0.0 12 20.0 106588.2 0.0 0.0 0. 0. 0.0 0.0 0.0 13 11.2 63741.2 0.0 0.0 0. 0. 0.0 0.0 0.0 14 8.5 49497.6 0.0 0.0 0. 0. 0.0 0.0 0.0 15 18.8 109976.8 0.0 0.0 0. 0. 0.0 0.0 0.0 16 7.0 40041.4 0.0 0.0 0. 0. 0.0 0.0 0.0 17 10.5 57304.6 0.0 0.0 0. 0. 0.0 0.0 0.0 18 0.2 1271.5 0.0 0.0 0. 0. 0.0 0.0 0.0 19 5.2 26023.8 0.0 0.0 0. 0. 0.0 0.0 0.0 20 10.4 46737.3 0.0 0.0 0. 0. 0.0 0.0 0.0 21 6.5 25662.9 0.0 0.0 0. 0. 0.0 0.0 0.0 22 1.9 6720.9 0.0 0.0 0. 0. 0.0 0.0 0.0 23 5.3 16808.4 0.0 0.0 0. 0. 0.0 0.0 0.0 24 11.3 22658.6 0.0 0.0 0. 0. 0.0 0.0 0.0 25 5.2 2949.0 0.0 0.0 0. 0. 0.0 0.0 0.0 Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 43.08 215.00 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-bc1.OUT Page 3

2 57.23 200.87 3 73.63 189.41 4 91.76 180.98 5 111.08 175.82 6 131.01 174.09 7 150.93 175.84 8 170.25 181.03 9 188.37 189.49 10 204.75 200.97 11 218.88 215.11 12 230.35 231.50 13 238.80 249.63 14 238.90 250.00 Circle Center At X = 130.92 ; Y = 288.84 ; and Radius = 114.75 Factor of Safety *** 2.155 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 52.31 215.00 2 66.56 200.97 3 82.99 189.56 4 101.11 181.11 5 120.41 175.85 6 140.32 173.94 7 160.26 175.43 8 179.66 180.28 9 197.96 188.36 10 214.62 199.42 11 229.17 213.15 12 241.18 229.14 13 250.29 246.94 14 251.25 250.00 Circle Center At X = 141.46 ; Y = 291.17 ; and Radius = 117.26 Factor of Safety *** 2.155 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 41.54 215.00 2 55.77 200.95 3 72.21 189.55 4 90.35 181.15 5 109.68 175.98 6 129.60 174.20 7 149.53 175.87 8 168.87 180.93 9 187.07 189.24 10 203.56 200.55 11 217.87 214.52 12 229.58 230.74 13 238.32 248.73 14 238.68 250.00 Circle Center At X = 129.87 ; Y = 290.19 ; and Radius = 116.00 Factor of Safety *** 2.162 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 41.54 215.00 2 57.16 202.51 3 74.28 192.17 4 92.59 184.13 5 111.80 178.55 6 131.56 175.50 7 151.56 175.06 8 171.44 177.22 9 190.88 181.94 10 209.53 189.15 11 227.09 198.73 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-bc1.OUT Page 4

12 243.25 210.51 13 257.75 224.28 14 270.33 239.83 15 276.57 250.00 Circle Center At X = 144.97 ; Y = 328.42 ; and Radius = 153.50 Factor of Safety *** 2.162 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 41.54 215.00 2 56.75 202.02 3 73.69 191.38 4 91.98 183.30 5 111.26 177.97 6 131.10 175.48 7 151.10 175.90 8 170.82 179.22 9 189.86 185.36 10 207.80 194.19 11 224.27 205.54 12 238.93 219.15 13 251.45 234.74 14 260.41 250.00 Circle Center At X = 138.15 ; Y = 312.69 ; and Radius = 137.40 Factor of Safety *** 2.169 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 30.77 215.00 2 46.37 202.49 3 63.46 192.09 4 81.74 183.99 5 100.92 178.32 6 120.67 175.17 7 140.67 174.60 8 160.56 176.61 9 180.04 181.17 10 198.76 188.21 11 216.41 197.61 12 232.70 209.21 13 247.36 222.81 14 260.15 238.20 15 267.61 250.00 Circle Center At X = 135.09 ; Y = 329.10 ; and Radius = 154.60 Factor of Safety *** 2.170 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 50.77 215.00 2 65.41 201.37 3 82.11 190.38 4 100.42 182.32 5 119.81 177.42 6 139.75 175.82 7 159.67 177.57 8 179.02 182.62 9 197.27 190.81 10 213.89 201.94 11 228.42 215.68 12 240.47 231.64 13 249.68 249.39 14 249.87 250.00 Circle Center At X = 139.27 ; Y = 295.36 ; and Radius = 119.55 Factor of Safety *** 2.171 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-bc1.OUT Page 5

No. (ft) (ft) 1 41.54 215.00 2 57.28 202.66 3 74.47 192.44 4 92.83 184.51 5 112.06 179.00 6 131.83 176.00 7 151.83 175.55 8 171.71 177.68 9 191.16 182.33 10 209.86 189.43 11 227.49 198.88 12 243.76 210.50 13 258.41 224.12 14 271.20 239.50 15 277.85 250.00 Circle Center At X = 145.28 ; Y = 331.16 ; and Radius = 155.74 Factor of Safety *** 2.181 *** Failure Surface Specified By 13 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 56.92 215.00 2 71.36 201.16 3 87.97 190.02 4 106.26 181.92 5 125.67 177.11 6 145.62 175.73 7 165.51 177.82 8 184.74 183.32 9 202.73 192.06 10 218.94 203.78 11 232.87 218.13 12 244.11 234.67 13 251.02 250.00 Circle Center At X = 143.57 ; Y = 290.91 ; and Radius = 115.20 Factor of Safety *** 2.185 *** **** END OF GSTABL7 OUTPUT **** RESCO; Valley Fill Stability; Section A-A'; Short-Term; Static; Block c:\geotechnical\saugus\2008\revised 2006 stabil\a-stat-sb1.pl2 Run By: nk 3/12/2008 10:04AM 400 # FS Soil Soil Total Saturated Cohesion Friction Piez. a 1.87 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface b 1.87 No. (pcf) (pcf) (psf) (deg) No. c 1.87 New-Ash 1 105.0 105.0 0.0 38.0 W1 d 1.87 Old-Ash 2 105.0 105.0 0.0 38.0 W1 e 1.88 MSW 3 75.0 75.0 0.0 28.0 W1 350 f 1.88 SandSilt 4 120.0 120.0 0.0 32.0 W1 g 1.89 Med-BBC 5 110.0 110.0 1000.0 0.0 W1 h 1.89 Till 6 130.0 130.0 0.0 34.0 W1 i 1.89 SluryWal 7 100.0 100.0 150.0 0.0 W1 j 1.89

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100 0 50 100 150 200 250 300 350 400 450 GSTABL7 v.2 FSmin=1.87 Safety Factors Are Calculated By The Simplified Janbu Method C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb1.OUT Page 1

*** GSTABL7 *** ** GSTABL7 by Garry H. Gregory, P.E. ** ** Original Version 1.0, January 1996; Current Version 2.003, June 2002 ** (All Rights Reserved-Unauthorized Use Prohibited) ********************************************************************************* SLOPE STABILITY ANALYSIS SYSTEM Modified Bishop, Simplified Janbu, or GLE Method of Slices. (Includes Spencer & Morgenstern-Price Type Analysis) Including Pier/Pile, Reinforcement, Soil Nail, Tieback, Nonlinear Undrained Shear Strength, Curved Phi Envelope, Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces. ********************************************************************************* Analysis Run Date: 3/12/2008 Time of Run: 10:04AM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb1.i n Output Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb1.O UT Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Revi2006 Stabil\a-stat-sb1.PLT PROBLEM DESCRIPTION: RESCO; Valley Fill Stability; Section A- A'; Short-Term; Static; Block BOUNDARY COORDINATES 8 Top Boundaries 22 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 214.00 22.00 215.00 4 2 22.00 215.00 25.00 215.00 7 3 25.00 215.00 62.00 215.00 3 4 62.00 215.00 85.00 219.50 2 5 85.00 219.50 100.00 217.80 2 6 100.00 217.80 115.00 220.00 2 7 115.00 220.00 205.00 250.00 1 8 205.00 250.00 450.00 250.00 1 9 115.00 220.00 160.00 217.00 2 10 160.00 217.00 310.00 217.00 2 11 310.00 217.00 450.00 222.00 2 12 62.00 215.00 450.00 215.00 3 13 25.00 215.00 25.01 200.00 7 14 25.01 200.00 450.00 200.00 4 15 25.01 200.00 25.03 190.00 7 16 25.03 190.00 450.00 190.00 5 17 22.00 215.00 22.01 190.00 4 18 0.00 190.00 22.01 190.00 5 19 22.01 190.00 22.03 185.00 5 20 22.03 185.00 25.00 185.00 5 21 25.00 185.00 25.03 190.00 5 22 0.00 174.00 450.00 174.00 6 User Specified Y-Origin = 100.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) ISOTROPIC SOIL PARAMETERS 7 Type(s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 105.0 105.0 0.0 38.0 0.00 0.0 1 2 105.0 105.0 0.0 38.0 0.00 0.0 1 3 75.0 75.0 0.0 28.0 0.00 0.0 1 4 120.0 120.0 0.0 32.0 0.00 0.0 1 5 110.0 110.0 1000.0 0.0 0.00 0.0 1 6 130.0 130.0 0.0 34.0 0.00 0.0 1 7 100.0 100.0 150.0 0.0 0.00 0.0 1 A Critical Failure Surface Searching Method, Using A Random Technique For Generating Sliding Block Surfaces, Has Been Specified. C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb1.OUT Page 2

The Active And Passive Portions Of The Sliding Surfaces Are Generated According To The Rankine Theory. 2000 Trial Surfaces Have Been Generated. 2 Boxes Specified For Generation Of Central Block Base Length Of Line Segments For Active And Passive Portions Of Sliding Block Is 20.0 Box X-Left Y-Left X-Right Y-Right Height No. (ft) (ft) (ft) (ft) (ft) 1 83.00 182.00 100.00 182.00 16.00 2 150.00 182.00 250.00 182.00 16.00 Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Simplified Janbu Method * * Total Number of Trial Surfaces Evaluated = 2000 Statistical Data On All Valid FS Values: FS Max = 2.853 FS Min = 1.870 FS Ave = 2.176 Standard Deviation = 0.169 Coefficient of Variation = 7.79 % Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 30.47 215.00 2 38.29 210.30 3 55.44 200.00 4 55.99 199.70 5 73.48 190.00 6 74.16 189.32 7 88.30 175.18 8 192.45 174.39 9 206.59 188.53 10 208.06 190.00 11 213.60 200.00 12 222.62 215.00 13 223.59 217.00 14 232.36 234.98 15 239.69 250.00 Factor of Safety *** 1.870 *** Individual data on the 20 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 7.8 1378.2 0.0 0.0 0. 0. 0.0 0.0 0.0 2 17.1 12664.2 0.0 0.0 0. 0. 0.0 0.0 0.0 3 0.5 626.6 0.0 0.0 0. 0. 0.0 0.0 0.0 4 6.0 8188.9 0.0 0.0 0. 0. 0.0 0.0 0.0 5 11.5 23657.5 0.0 0.0 0. 0. 0.0 0.0 0.0 6 0.7 1769.3 0.0 0.0 0. 0. 0.0 0.0 0.0 7 10.8 36402.5 0.0 0.0 0. 0. 0.0 0.0 0.0 8 3.3 13944.1 0.0 0.0 0. 0. 0.0 0.0 0.0 9 11.7 50593.2 0.0 0.0 0. 0. 0.0 0.0 0.0 10 15.0 65712.6 0.0 0.0 0. 0. 0.0 0.0 0.0 11 45.0 238898.0 0.0 0.0 0. 0. 0.0 0.0 0.0 12 32.4 217300.8 0.0 0.0 0. 0. 0.0 0.0 0.0 13 12.6 85431.5 0.0 0.0 0. 0. 0.0 0.0 0.0 14 1.6 9949.1 0.0 0.0 0. 0. 0.0 0.0 0.0 15 1.5 8927.9 0.0 0.0 0. 0. 0.0 0.0 0.0 16 5.5 29932.7 0.0 0.0 0. 0. 0.0 0.0 0.0 17 9.0 38192.2 0.0 0.0 0. 0. 0.0 0.0 0.0 18 1.0 3482.4 0.0 0.0 0. 0. 0.0 0.0 0.0 19 8.8 22105.0 0.0 0.0 0. 0. 0.0 0.0 0.0 20 7.3 5779.9 0.0 0.0 0. 0. 0.0 0.0 0.0 Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 30.47 215.00 2 38.29 210.30 3 55.44 200.00 4 55.99 199.70 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb1.OUT Page 3

5 73.48 190.00 6 74.16 189.32 7 88.30 175.18 8 192.45 174.39 9 206.59 188.53 10 208.06 190.00 11 213.60 200.00 12 222.62 215.00 13 223.59 217.00 14 232.36 234.98 15 239.69 250.00 Factor of Safety *** 1.870 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 32.69 215.00 2 40.51 210.30 3 57.65 200.00 4 58.20 199.70 5 75.69 190.00 6 89.83 175.87 7 185.81 174.58 8 199.95 188.72 9 201.23 190.00 10 206.78 200.00 11 215.79 215.00 12 216.76 217.00 13 225.53 234.98 14 232.86 250.00 Factor of Safety *** 1.874 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 32.69 215.00 2 40.51 210.30 3 57.65 200.00 4 58.20 199.70 5 75.69 190.00 6 89.83 175.87 7 185.81 174.58 8 199.95 188.72 9 201.23 190.00 10 206.78 200.00 11 215.79 215.00 12 216.76 217.00 13 225.53 234.98 14 232.86 250.00 Factor of Safety *** 1.874 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 28.26 215.00 2 36.08 210.30 3 53.22 200.00 4 53.77 199.70 5 71.26 190.00 6 72.63 188.63 7 86.77 174.49 8 199.09 174.20 9 213.23 188.34 10 214.89 190.00 11 220.43 200.00 12 229.44 215.00 13 230.42 217.00 14 239.19 234.98 15 246.52 250.00 Factor of Safety C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb1.OUT Page 4

*** 1.881 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 28.26 215.00 2 36.08 210.30 3 53.22 200.00 4 53.77 199.70 5 71.26 190.00 6 72.63 188.63 7 86.77 174.49 8 199.09 174.20 9 213.23 188.34 10 214.89 190.00 11 220.43 200.00 12 229.44 215.00 13 230.42 217.00 14 239.19 234.98 15 246.52 250.00 Factor of Safety *** 1.881 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 34.24 215.00 2 42.06 210.30 3 59.20 200.00 4 59.75 199.70 5 77.24 190.00 6 78.67 188.57 7 92.81 174.43 8 181.51 175.64 9 195.65 189.78 10 195.87 190.00 11 201.42 200.00 12 210.43 215.00 13 211.40 217.00 14 220.17 234.98 15 227.50 250.00 Factor of Safety *** 1.889 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 34.24 215.00 2 42.06 210.30 3 59.20 200.00 4 59.75 199.70 5 77.24 190.00 6 78.67 188.57 7 92.81 174.43 8 181.51 175.64 9 195.65 189.78 10 195.87 190.00 11 201.42 200.00 12 210.43 215.00 13 211.40 217.00 14 220.17 234.98 15 227.50 250.00 Factor of Safety *** 1.889 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 34.81 215.00 2 42.63 210.30 3 59.77 200.00 4 60.32 199.70 5 77.81 190.00 6 78.22 189.59 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb1.OUT Page 5

7 92.37 175.44 8 192.16 176.28 9 205.88 190.00 10 211.42 200.00 11 220.43 215.00 12 221.41 217.00 13 230.18 234.98 14 237.50 250.00 Factor of Safety *** 1.889 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 34.81 215.00 2 42.63 210.30 3 59.77 200.00 4 60.32 199.70 5 77.81 190.00 6 78.22 189.59 7 92.37 175.44 8 192.16 176.28 9 205.88 190.00 10 211.42 200.00 11 220.43 215.00 12 221.41 217.00 13 230.18 234.98 14 237.50 250.00 Factor of Safety *** 1.889 *** **** END OF GSTABL7 OUTPUT **** RESCO; Valley Fill Stability; Section A-A'; Short-Term; Static; Block; SluryWal c:\geotechnical\saugus\2008\revised 2006 stabil\a-stat-sb2.pl2 Run By: nk 3/12/2008 10:04AM 400 # FS Soil Soil Total Saturated Cohesion Friction Piez. a 2.06 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface b 2.06 No. (pcf) (pcf) (psf) (deg) No. c 2.06 New-Ash 1 105.0 105.0 0.0 38.0 W1 d 2.06 Old-Ash 2 105.0 105.0 0.0 38.0 W1 e 2.14 MSW 3 75.0 75.0 0.0 28.0 W1 350 f 2.14 SandSilt 4 120.0 120.0 0.0 32.0 W1 g 2.14 Med-BBC 5 110.0 110.0 1000.0 0.0 W1 h 2.14 Till 6 130.0 130.0 0.0 34.0 W1 i 2.16 SluryWal 7 100.0 100.0 150.0 0.0 W1 j 2.16

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150

100 0 50 100 150 200 250 300 350 400 450 GSTABL7 v.2 FSmin=2.06 Safety Factors Are Calculated By The Simplified Janbu Method C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb2.OUT Page 1

*** GSTABL7 *** ** GSTABL7 by Garry H. Gregory, P.E. ** ** Original Version 1.0, January 1996; Current Version 2.003, June 2002 ** (All Rights Reserved-Unauthorized Use Prohibited) ********************************************************************************* SLOPE STABILITY ANALYSIS SYSTEM Modified Bishop, Simplified Janbu, or GLE Method of Slices. (Includes Spencer & Morgenstern-Price Type Analysis) Including Pier/Pile, Reinforcement, Soil Nail, Tieback, Nonlinear Undrained Shear Strength, Curved Phi Envelope, Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces. ********************************************************************************* Analysis Run Date: 3/12/2008 Time of Run: 10:04AM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb2.i n Output Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb2.O UT Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Revi2006 Stabil\a-stat-sb2.PLT PROBLEM DESCRIPTION: RESCO; Valley Fill Stability; Section A- A'; Short-Term; Static; Block; SluryWal BOUNDARY COORDINATES 8 Top Boundaries 22 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 214.00 22.00 215.00 4 2 22.00 215.00 25.00 215.00 7 3 25.00 215.00 62.00 215.00 3 4 62.00 215.00 85.00 219.50 2 5 85.00 219.50 100.00 217.80 2 6 100.00 217.80 115.00 220.00 2 7 115.00 220.00 205.00 250.00 1 8 205.00 250.00 450.00 250.00 1 9 115.00 220.00 160.00 217.00 2 10 160.00 217.00 310.00 217.00 2 11 310.00 217.00 450.00 222.00 2 12 62.00 215.00 450.00 215.00 3 13 25.00 215.00 25.01 200.00 7 14 25.01 200.00 450.00 200.00 4 15 25.01 200.00 25.03 190.00 7 16 25.03 190.00 450.00 190.00 5 17 22.00 215.00 22.01 190.00 4 18 0.00 190.00 22.01 190.00 5 19 22.01 190.00 22.03 185.00 5 20 22.03 185.00 25.00 185.00 5 21 25.00 185.00 25.03 190.00 5 22 0.00 174.00 450.00 174.00 6 User Specified Y-Origin = 100.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) ISOTROPIC SOIL PARAMETERS 7 Type(s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 105.0 105.0 0.0 38.0 0.00 0.0 1 2 105.0 105.0 0.0 38.0 0.00 0.0 1 3 75.0 75.0 0.0 28.0 0.00 0.0 1 4 120.0 120.0 0.0 32.0 0.00 0.0 1 5 110.0 110.0 1000.0 0.0 0.00 0.0 1 6 130.0 130.0 0.0 34.0 0.00 0.0 1 7 100.0 100.0 150.0 0.0 0.00 0.0 1 A Critical Failure Surface Searching Method, Using A Random Technique For Generating Sliding Block Surfaces, Has Been Specified. C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb2.OUT Page 2

The Active And Passive Portions Of The Sliding Surfaces Are Generated According To The Rankine Theory. 2000 Trial Surfaces Have Been Generated. 4 Boxes Specified For Generation Of Central Block Base Length Of Line Segments For Active And Passive Portions Of Sliding Block Is 15.0 Box X-Left Y-Left X-Right Y-Right Height No. (ft) (ft) (ft) (ft) (ft) 1 22.00 214.00 22.50 214.00 0.50 2 24.50 186.00 25.00 186.00 1.00 3 30.00 182.00 100.00 182.00 16.00 4 150.00 182.00 350.00 182.00 16.00 Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Simplified Janbu Method * * Total Number of Trial Surfaces Evaluated = 2000 Statistical Data On All Valid FS Values: FS Max = 3.856 FS Min = 2.064 FS Ave = 2.803 Standard Deviation = 0.352 Coefficient of Variation = 12.54 % Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.34 214.92 2 22.00 214.00 3 22.12 213.88 4 24.93 186.21 5 66.24 175.54 6 187.05 174.12 7 197.65 184.73 8 202.92 190.00 9 208.47 200.00 10 216.19 212.86 11 217.48 215.00 12 218.46 217.00 13 225.03 230.48 14 231.61 243.96 15 234.55 250.00 Factor of Safety *** 2.064 *** Individual data on the 24 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 1.7 99.1 0.0 0.0 0. 0. 0.0 0.0 0.0 2 0.1 13.1 0.0 0.0 0. 0. 0.0 0.0 0.0 3 2.8 4196.6 0.0 0.0 0. 0. 0.0 0.0 0.0 4 0.1 198.7 0.0 0.0 0. 0. 0.0 0.0 0.0 5 0.0 19.6 0.0 0.0 0. 0. 0.0 0.0 0.0 6 0.0 7.3 0.0 0.0 0. 0. 0.0 0.0 0.0 7 0.0 52.6 0.0 0.0 0. 0. 0.0 0.0 0.0 8 37.0 120886.8 0.0 0.0 0. 0. 0.0 0.0 0.0 9 4.2 16545.0 0.0 0.0 0. 0. 0.0 0.0 0.0 10 18.8 78923.0 0.0 0.0 0. 0. 0.0 0.0 0.0 11 15.0 64993.0 0.0 0.0 0. 0. 0.0 0.0 0.0 12 15.0 65676.5 0.0 0.0 0. 0. 0.0 0.0 0.0 13 45.0 239402.7 0.0 0.0 0. 0. 0.0 0.0 0.0 14 27.0 179257.2 0.0 0.0 0. 0. 0.0 0.0 0.0 15 10.6 71279.5 0.0 0.0 0. 0. 0.0 0.0 0.0 16 5.3 32274.7 0.0 0.0 0. 0. 0.0 0.0 0.0 17 2.1 11912.3 0.0 0.0 0. 0. 0.0 0.0 0.0 18 3.5 17944.9 0.0 0.0 0. 0. 0.0 0.0 0.0 19 7.7 33357.8 0.0 0.0 0. 0. 0.0 0.0 0.0 20 1.3 4834.4 0.0 0.0 0. 0. 0.0 0.0 0.0 21 1.0 3482.4 0.0 0.0 0. 0. 0.0 0.0 0.0 22 6.6 18130.1 0.0 0.0 0. 0. 0.0 0.0 0.0 23 6.6 8821.8 0.0 0.0 0. 0. 0.0 0.0 0.0 24 2.9 933.0 0.0 0.0 0. 0. 0.0 0.0 0.0 Failure Surface Specified By 15 Coordinate Points C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb2.OUT Page 3

Point X-Surf Y-Surf No. (ft) (ft) 1 20.34 214.92 2 22.00 214.00 3 22.12 213.88 4 24.93 186.21 5 66.24 175.54 6 187.05 174.12 7 197.65 184.73 8 202.92 190.00 9 208.47 200.00 10 216.19 212.86 11 217.48 215.00 12 218.46 217.00 13 225.03 230.48 14 231.61 243.96 15 234.55 250.00 Factor of Safety *** 2.064 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.34 214.92 2 22.00 214.00 3 22.12 213.88 4 24.93 186.21 5 66.24 175.54 6 187.05 174.12 7 197.65 184.73 8 202.92 190.00 9 208.47 200.00 10 216.19 212.86 11 217.48 215.00 12 218.46 217.00 13 225.03 230.48 14 231.61 243.96 15 234.55 250.00 Factor of Safety *** 2.064 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.34 214.92 2 22.00 214.00 3 22.12 213.88 4 24.93 186.21 5 66.24 175.54 6 187.05 174.12 7 197.65 184.73 8 202.92 190.00 9 208.47 200.00 10 216.19 212.86 11 217.48 215.00 12 218.46 217.00 13 225.03 230.48 14 231.61 243.96 15 234.55 250.00 Factor of Safety *** 2.064 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.93 214.95 2 22.00 214.36 3 22.31 214.05 4 24.75 186.22 5 78.55 174.10 6 178.45 175.19 7 189.06 185.79 8 193.27 190.00 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb2.OUT Page 4

9 198.81 200.00 10 206.54 212.86 11 207.82 215.00 12 208.80 217.00 13 215.38 230.48 14 221.95 243.96 15 224.89 250.00 Factor of Safety *** 2.142 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.93 214.95 2 22.00 214.36 3 22.31 214.05 4 24.75 186.22 5 78.55 174.10 6 178.45 175.19 7 189.06 185.79 8 193.27 190.00 9 198.81 200.00 10 206.54 212.86 11 207.82 215.00 12 208.80 217.00 13 215.38 230.48 14 221.95 243.96 15 224.89 250.00 Factor of Safety *** 2.142 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.93 214.95 2 22.00 214.36 3 22.31 214.05 4 24.75 186.22 5 78.55 174.10 6 178.45 175.19 7 189.06 185.79 8 193.27 190.00 9 198.81 200.00 10 206.54 212.86 11 207.82 215.00 12 208.80 217.00 13 215.38 230.48 14 221.95 243.96 15 224.89 250.00 Factor of Safety *** 2.142 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.93 214.95 2 22.00 214.36 3 22.31 214.05 4 24.75 186.22 5 78.55 174.10 6 178.45 175.19 7 189.06 185.79 8 193.27 190.00 9 198.81 200.00 10 206.54 212.86 11 207.82 215.00 12 208.80 217.00 13 215.38 230.48 14 221.95 243.96 15 224.89 250.00 Factor of Safety *** 2.142 *** Failure Surface Specified By 15 Coordinate Points C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-stat-sb2.OUT Page 5

Point X-Surf Y-Surf No. (ft) (ft) 1 20.85 214.95 2 22.00 214.31 3 22.10 214.21 4 24.90 186.16 5 87.43 177.51 6 194.47 176.84 7 205.08 187.45 8 207.63 190.00 9 213.17 200.00 10 220.90 212.86 11 222.18 215.00 12 223.16 217.00 13 229.73 230.48 14 236.31 243.96 15 239.25 250.00 Factor of Safety *** 2.155 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.85 214.95 2 22.00 214.31 3 22.10 214.21 4 24.90 186.16 5 87.43 177.51 6 194.47 176.84 7 205.08 187.45 8 207.63 190.00 9 213.17 200.00 10 220.90 212.86 11 222.18 215.00 12 223.16 217.00 13 229.73 230.48 14 236.31 243.96 15 239.25 250.00 Factor of Safety *** 2.155 *** **** END OF GSTABL7 OUTPUT ****

C-2 Results of Seismic Slope Stability Analysis

N:\projects\119504\2008\VF FEP Docs\Global Stability

Estimation of Seismically-Induced Permanent Displacement Seismic Slope Stability of Cross Section Across Phase IV Saugus RESCO Landfill

Based on USGS (2002) seismic hazard mapping, the peak ground acceleration (PGA) having a10% probability of exceedance in 250 years (this is equivalent to 2% probability in 50 years) = 0.16g

Mean earthquake magnitude (M) = 6.0

Based on pseudo-static slope stability analysis, the yield acceleration (k y) = 0.151g

Conservatively, assume that the maximum acceleration within the critical slope failure surface (averaged spatially) is equal to the PGA; i.e., k max = 0.151g

Therefore, k y/k max = 0.151g/0.16g = 0.94

From the Makdisi and Seed (1978) chart shown below, for an Earthquake magnitude of 6.0 and k y/k max = 0.94, the likely maximum permanent displacement, (U max ) ≈ 0.3 cm ≈ 0.1 inches

Umax ≈ 0.3 cm

0.94

RESCO; Valley Fill Stability; Section A-A'; Short-Term; Y-Acc; Circle c:\geotechnical\saugus\2008\revised 2006 stabil\a-yacc-bc1.pl2 Run By: nk 3/12/2008 10:05AM 400 # FS Soil Soil Total Saturated Cohesion Friction Piez. Load Value a 1.00 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface Peak(A) 0.402(g) b 1.01 No. (pcf) (pcf) (psf) (deg) No. kh Coef. 0.201(g)< c 1.01 New-Ash 1 105.0 105.0 0.0 38.0 W1 d 1.02 Old-Ash 2 105.0 105.0 0.0 38.0 W1 e 1.02 MSW 3 75.0 75.0 0.0 28.0 W1 350 f 1.02 SandSilt 4 120.0 120.0 0.0 32.0 W1 g 1.02 Med-BBC 5 110.0 110.0 1015.0 0.0 W1 h 1.02 Till 6 130.0 130.0 0.0 34.0 W1 i 1.02 SluryWal 7 100.0 100.0 150.0 0.0 W1 j 1.02

300

a j i h g e df b c 250 1

2 2 2 2 4 7 3 2 2 3 7 200 4 7 4 5 5 5 5 5 6

150

100 0 50 100 150 200 250 300 350 400 450 GSTABL7 v.2 FSmin=1.00 Safety Factors Are Calculated By The Modified Bishop Method C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.OUT Page 1

*** GSTABL7 *** ** GSTABL7 by Garry H. Gregory, P.E. ** ** Original Version 1.0, January 1996; Current Version 2.003, June 2002 ** (All Rights Reserved-Unauthorized Use Prohibited) ********************************************************************************* SLOPE STABILITY ANALYSIS SYSTEM Modified Bishop, Simplified Janbu, or GLE Method of Slices. (Includes Spencer & Morgenstern-Price Type Analysis) Including Pier/Pile, Reinforcement, Soil Nail, Tieback, Nonlinear Undrained Shear Strength, Curved Phi Envelope, Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces. ********************************************************************************* Analysis Run Date: 3/12/2008 Time of Run: 10:05AM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.i n Output Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.O UT Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Revi2006 Stabil\a-yacc-bc1.PLT PROBLEM DESCRIPTION: RESCO; Valley Fill Stability; Section A- A'; Short-Term; Y-Acc; Circle BOUNDARY COORDINATES 8 Top Boundaries 22 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 214.00 22.00 215.00 4 2 22.00 215.00 25.00 215.00 7 3 25.00 215.00 62.00 215.00 3 4 62.00 215.00 85.00 219.50 2 5 85.00 219.50 100.00 217.80 2 6 100.00 217.80 115.00 220.00 2 7 115.00 220.00 205.00 250.00 1 8 205.00 250.00 450.00 250.00 1 9 115.00 220.00 160.00 217.00 2 10 160.00 217.00 310.00 217.00 2 11 310.00 217.00 450.00 222.00 2 12 62.00 215.00 450.00 215.00 3 13 25.00 215.00 25.01 200.00 7 14 25.01 200.00 450.00 200.00 4 15 25.01 200.00 25.03 190.00 7 16 25.03 190.00 450.00 190.00 5 17 22.00 215.00 22.01 190.00 4 18 0.00 190.00 22.01 190.00 5 19 22.01 190.00 22.03 185.00 5 20 22.03 185.00 25.00 185.00 5 21 25.00 185.00 25.03 190.00 5 22 0.00 174.00 450.00 174.00 6 User Specified Y-Origin = 100.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) ISOTROPIC SOIL PARAMETERS 7 Type(s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 105.0 105.0 0.0 38.0 0.00 0.0 1 2 105.0 105.0 0.0 38.0 0.00 0.0 1 3 75.0 75.0 0.0 28.0 0.00 0.0 1 4 120.0 120.0 0.0 32.0 0.00 0.0 1 5 110.0 110.0 1015.0 0.0 0.00 0.0 1 6 130.0 130.0 0.0 34.0 0.00 0.0 1 7 100.0 100.0 150.0 0.0 0.00 0.0 1 Specified Peak Ground Acceleration Coefficient (A) = 0.402(g) Specified Horizontal Earthquake Coefficient (kh) = 0.201(g) Specified Vertical Earthquake Coefficient (kv) = 0.000(g) C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.OUT Page 2

Specified Seismic Pore-Pressure Factor = 0.000 A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified. 1600 Trial Surfaces Have Been Generated. 40 Surface(s) Initiate(s) From Each Of 40 Points Equally Spaced Along The Ground Surface Between X = 0.00(ft) and X = 60.00(ft) Each Surface Terminates Between X = 120.00(ft) and X = 400.00(ft) Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = 0.00(ft) 20.00(ft) Line Segments Define Each Trial Failure Surface. Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Modified Bishop Method * * Total Number of Trial Surfaces Evaluated = 1600 Statistical Data On All Valid FS Values: FS Max = 3.413 FS Min = 1.002 FS Ave = 1.909 Standard Deviation = 0.499 Coefficient of Variation = 26.16 % Failure Surface Specified By 17 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 36.92 215.00 2 53.37 203.63 3 70.89 193.97 4 89.29 186.13 5 108.38 180.18 6 127.98 176.19 7 147.88 174.19 8 167.88 174.21 9 187.78 176.25 10 207.37 180.28 11 226.45 186.26 12 244.83 194.14 13 262.33 203.83 14 278.75 215.24 15 293.95 228.24 16 307.76 242.71 17 313.42 250.00 Circle Center At X = 157.68 ; Y = 372.09 ; and Radius = 198.14 Factor of Safety *** 1.002 *** Individual data on the 28 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 16.5 7016.6 0.0 0.0 0. 0. 1410.3 0.0 0.0 2 6.6 6504.7 0.0 0.0 0. 0. 1307.4 0.0 0.0 3 2.0 2443.6 0.0 0.0 0. 0. 491.2 0.0 0.0 4 8.9 14629.4 0.0 0.0 0. 0. 2940.5 0.0 0.0 5 9.3 22024.7 0.0 0.0 0. 0. 4427.0 0.0 0.0 6 4.8 13729.2 0.0 0.0 0. 0. 2759.6 0.0 0.0 7 4.3 13278.0 0.0 0.0 0. 0. 2668.9 0.0 0.0 8 10.7 35271.4 0.0 0.0 0. 0. 7089.5 0.0 0.0 9 8.4 30344.0 0.0 0.0 0. 0. 6099.2 0.0 0.0 10 6.6 26164.5 0.0 0.0 0. 0. 5259.1 0.0 0.0 11 13.0 57772.6 0.0 0.0 0. 0. 11612.3 0.0 0.0 12 19.9 105107.4 0.0 0.0 0. 0. 21126.6 0.0 0.0 13 12.1 72132.5 0.0 0.0 0. 0. 14498.6 0.0 0.0 14 7.9 49641.6 0.0 0.0 0. 0. 9978.0 0.0 0.0 15 19.9 132782.9 0.0 0.0 0. 0. 26689.4 0.0 0.0 16 17.2 120855.4 0.0 0.0 0. 0. 24291.9 0.0 0.0 17 2.4 16782.8 0.0 0.0 0. 0. 3373.3 0.0 0.0 18 19.1 128625.9 0.0 0.0 0. 0. 25853.8 0.0 0.0 19 8.7 54099.5 0.0 0.0 0. 0. 10874.0 0.0 0.0 20 9.7 55586.2 0.0 0.0 0. 0. 11172.8 0.0 0.0 21 10.6 54469.9 0.0 0.0 0. 0. 10948.5 0.0 0.0 22 6.9 32226.2 0.0 0.0 0. 0. 6477.5 0.0 0.0 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.OUT Page 3

23 16.1 65837.0 0.0 0.0 0. 0. 13233.2 0.0 0.0 24 0.3 1267.8 0.0 0.0 0. 0. 254.8 0.0 0.0 25 2.1 7314.4 0.0 0.0 0. 0. 1470.2 0.0 0.0 26 13.1 37770.1 0.0 0.0 0. 0. 7591.8 0.0 0.0 27 13.8 21050.6 0.0 0.0 0. 0. 4231.2 0.0 0.0 28 5.7 2167.2 0.0 0.0 0. 0. 435.6 0.0 0.0 Failure Surface Specified By 18 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 49.23 215.00 2 66.20 204.42 3 84.01 195.32 4 102.54 187.78 5 121.64 181.85 6 141.17 177.57 7 161.00 174.97 8 180.98 174.08 9 200.97 174.90 10 220.81 177.41 11 240.36 181.62 12 259.48 187.48 13 278.04 194.95 14 295.88 203.97 15 312.90 214.49 16 328.95 226.42 17 343.92 239.68 18 353.74 250.00 Circle Center At X = 181.34 ; Y = 407.75 ; and Radius = 233.68 Factor of Safety *** 1.005 *** Failure Surface Specified By 18 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 53.85 215.00 2 70.93 204.60 3 88.81 195.64 4 107.37 188.19 5 126.48 182.29 6 146.01 177.99 7 165.83 175.31 8 185.81 174.28 9 205.80 174.89 10 225.67 177.16 11 245.28 181.05 12 264.51 186.55 13 283.23 193.61 14 301.29 202.19 15 318.59 212.24 16 334.99 223.67 17 350.40 236.42 18 364.30 250.00 Circle Center At X = 188.32 ; Y = 416.59 ; and Radius = 242.32 Factor of Safety *** 1.012 *** Failure Surface Specified By 22 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 12.31 214.56 2 30.34 205.90 3 48.82 198.25 4 67.69 191.65 5 86.91 186.10 6 106.40 181.63 7 126.12 178.26 8 145.99 175.98 9 165.95 174.81 10 185.95 174.75 11 205.92 175.81 12 225.81 177.97 13 245.54 181.24 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.OUT Page 4

14 265.06 185.59 15 284.31 191.03 16 303.22 197.53 17 321.74 205.07 18 339.82 213.63 19 357.39 223.18 20 374.41 233.69 21 390.81 245.13 22 397.03 250.00 Circle Center At X = 176.89 ; Y = 533.81 ; and Radius = 359.18 Factor of Safety *** 1.016 *** Failure Surface Specified By 20 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 46.15 215.00 2 63.69 205.38 3 81.85 197.01 4 100.56 189.94 5 119.72 184.19 6 139.23 179.79 7 159.00 176.78 8 178.93 175.15 9 198.93 174.93 10 218.90 176.10 11 238.73 178.67 12 258.34 182.63 13 277.62 187.94 14 296.48 194.59 15 314.83 202.55 16 332.57 211.77 17 349.63 222.21 18 365.92 233.82 19 381.35 246.55 20 384.99 250.00 Circle Center At X = 192.07 ; Y = 459.99 ; and Radius = 285.15 Factor of Safety *** 1.018 *** Failure Surface Specified By 22 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 18.46 214.84 2 36.46 206.12 3 54.92 198.43 4 73.79 191.79 5 93.00 186.24 6 112.50 181.77 7 132.22 178.42 8 152.09 176.19 9 172.06 175.09 10 192.06 175.11 11 212.03 176.27 12 231.90 178.56 13 251.60 181.96 14 271.09 186.48 15 290.28 192.08 16 309.13 198.77 17 327.58 206.51 18 345.55 215.28 19 363.00 225.05 20 379.87 235.80 21 396.10 247.48 22 399.22 250.00 Circle Center At X = 181.52 ; Y = 528.22 ; and Radius = 353.26 Factor of Safety *** 1.020 *** Failure Surface Specified By 20 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 52.31 215.00 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.OUT Page 5

2 69.87 205.43 3 88.05 197.09 4 106.76 190.03 5 125.92 184.28 6 145.42 179.86 7 165.19 176.80 8 185.11 175.10 9 205.11 174.79 10 225.08 175.85 11 244.93 178.30 12 264.57 182.10 13 283.89 187.25 14 302.82 193.72 15 321.25 201.48 16 339.10 210.50 17 356.29 220.72 18 372.74 232.10 19 388.36 244.60 20 394.23 250.00 Circle Center At X = 199.56 ; Y = 464.08 ; and Radius = 289.36 Factor of Safety *** 1.022 *** Failure Surface Specified By 18 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 58.46 215.00 2 75.35 204.28 3 93.13 195.12 4 111.65 187.59 5 130.78 181.74 6 150.35 177.63 7 170.21 175.29 8 190.21 174.74 9 210.17 175.98 10 229.94 179.00 11 249.36 183.78 12 268.28 190.27 13 286.53 198.44 14 303.99 208.20 15 320.49 219.49 16 335.93 232.22 17 350.16 246.27 18 353.31 250.00 Circle Center At X = 186.29 ; Y = 397.56 ; and Radius = 222.87 Factor of Safety *** 1.022 *** Failure Surface Specified By 17 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 29.23 215.00 2 46.04 204.16 3 63.78 194.93 4 82.31 187.40 5 101.46 181.63 6 121.06 177.67 7 140.95 175.55 8 160.95 175.30 9 180.88 176.91 10 200.58 180.37 11 219.87 185.66 12 238.58 192.72 13 256.55 201.50 14 273.63 211.91 15 289.66 223.87 16 304.50 237.27 17 316.19 250.00 Circle Center At X = 153.65 ; Y = 389.43 ; and Radius = 214.26 Factor of Safety *** 1.022 *** Failure Surface Specified By 22 Coordinate Points C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-bc1.OUT Page 6

Point X-Surf Y-Surf No. (ft) (ft) 1 7.69 214.35 2 25.75 205.75 3 44.25 198.16 4 63.15 191.60 5 82.37 186.10 6 101.88 181.66 7 121.59 178.30 8 141.46 176.03 9 161.43 174.87 10 181.43 174.80 11 201.40 175.84 12 221.29 177.98 13 241.02 181.21 14 260.55 185.53 15 279.82 190.91 16 298.75 197.35 17 317.30 204.82 18 335.41 213.30 19 353.03 222.77 20 370.10 233.20 21 386.57 244.55 22 393.61 250.00 Circle Center At X = 172.50 ; Y = 536.92 ; and Radius = 362.24 Factor of Safety *** 1.023 *** **** END OF GSTABL7 OUTPUT **** RESCO; Valley Fill Stability; Section A-A'; Short-Term; Y-Acc; Block c:\geotechnical\saugus\2008\revised 2006 stabil\a-yacc-sb1.pl2 Run By: nk 3/12/2008 10:08AM 400 # FS Soil Soil Total Saturated Cohesion Friction Piez. Load Value a 1.00 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface Peak(A) 0.308(g) b 1.00 No. (pcf) (pcf) (psf) (deg) No. kh Coef. 0.154(g)< c 1.00 New-Ash 1 105.0 105.0 0.0 38.0 W1 d 1.00 Old-Ash 2 105.0 105.0 0.0 38.0 W1 e 1.01 MSW 3 75.0 75.0 0.0 28.0 W1 350 f 1.01 SandSilt 4 120.0 120.0 0.0 32.0 W1 g 1.01 Med-BBC 5 110.0 110.0 1000.0 0.0 W1 h 1.01 Till 6 130.0 130.0 0.0 34.0 W1 i 1.01 SluryWal 7 100.0 100.0 150.0 0.0 W1 j 1.01

300

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100 0 50 100 150 200 250 300 350 400 450 GSTABL7 v.2 FSmin=1.00 Safety Factors Are Calculated By The Simplified Janbu Method C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb1.OUT Page 1

*** GSTABL7 *** ** GSTABL7 by Garry H. Gregory, P.E. ** ** Original Version 1.0, January 1996; Current Version 2.003, June 2002 ** (All Rights Reserved-Unauthorized Use Prohibited) ********************************************************************************* SLOPE STABILITY ANALYSIS SYSTEM Modified Bishop, Simplified Janbu, or GLE Method of Slices. (Includes Spencer & Morgenstern-Price Type Analysis) Including Pier/Pile, Reinforcement, Soil Nail, Tieback, Nonlinear Undrained Shear Strength, Curved Phi Envelope, Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces. ********************************************************************************* Analysis Run Date: 3/12/2008 Time of Run: 10:08AM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb1.i n Output Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb1.O UT Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Revi2006 Stabil\a-yacc-sb1.PLT PROBLEM DESCRIPTION: RESCO; Valley Fill Stability; Section A- A'; Short-Term; Y-Acc; Block BOUNDARY COORDINATES 8 Top Boundaries 22 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 214.00 22.00 215.00 4 2 22.00 215.00 25.00 215.00 7 3 25.00 215.00 62.00 215.00 3 4 62.00 215.00 85.00 219.50 2 5 85.00 219.50 100.00 217.80 2 6 100.00 217.80 115.00 220.00 2 7 115.00 220.00 205.00 250.00 1 8 205.00 250.00 450.00 250.00 1 9 115.00 220.00 160.00 217.00 2 10 160.00 217.00 310.00 217.00 2 11 310.00 217.00 450.00 222.00 2 12 62.00 215.00 450.00 215.00 3 13 25.00 215.00 25.01 200.00 7 14 25.01 200.00 450.00 200.00 4 15 25.01 200.00 25.03 190.00 7 16 25.03 190.00 450.00 190.00 5 17 22.00 215.00 22.01 190.00 4 18 0.00 190.00 22.01 190.00 5 19 22.01 190.00 22.03 185.00 5 20 22.03 185.00 25.00 185.00 5 21 25.00 185.00 25.03 190.00 5 22 0.00 174.00 450.00 174.00 6 User Specified Y-Origin = 100.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) ISOTROPIC SOIL PARAMETERS 7 Type(s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 105.0 105.0 0.0 38.0 0.00 0.0 1 2 105.0 105.0 0.0 38.0 0.00 0.0 1 3 75.0 75.0 0.0 28.0 0.00 0.0 1 4 120.0 120.0 0.0 32.0 0.00 0.0 1 5 110.0 110.0 1000.0 0.0 0.00 0.0 1 6 130.0 130.0 0.0 34.0 0.00 0.0 1 7 100.0 100.0 150.0 0.0 0.00 0.0 1 Specified Peak Ground Acceleration Coefficient (A) = 0.308(g) Specified Horizontal Earthquake Coefficient (kh) = 0.154(g) Specified Vertical Earthquake Coefficient (kv) = 0.000(g) C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb1.OUT Page 2

Specified Seismic Pore-Pressure Factor = 0.000 A Critical Failure Surface Searching Method, Using A Random Technique For Generating Sliding Block Surfaces, Has Been Specified. The Active And Passive Portions Of The Sliding Surfaces Are Generated According To The Rankine Theory. 2000 Trial Surfaces Have Been Generated. 2 Boxes Specified For Generation Of Central Block Base Length Of Line Segments For Active And Passive Portions Of Sliding Block Is 20.0 Box X-Left Y-Left X-Right Y-Right Height No. (ft) (ft) (ft) (ft) (ft) 1 83.00 182.00 120.00 182.00 16.00 2 150.00 182.00 250.00 182.00 16.00 Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Simplified Janbu Method * * Total Number of Trial Surfaces Evaluated = 2000 Statistical Data On All Valid FS Values: FS Max = 1.616 FS Min = 0.997 FS Ave = 1.190 Standard Deviation = 0.119 Coefficient of Variation = 9.98 % Failure Surface Specified By 16 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 24.83 215.00 2 25.00 214.83 3 32.53 210.30 4 49.68 200.00 5 50.22 199.70 6 67.72 190.00 7 69.44 188.27 8 83.58 174.13 9 223.02 174.47 10 237.16 188.61 11 238.55 190.00 12 244.09 200.00 13 253.10 215.00 14 254.08 217.00 15 262.85 234.98 16 270.18 250.00 Factor of Safety *** 0.997 *** Individual data on the 21 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 0.2 1.5 0.0 0.0 0. 0. 0.2 0.0 0.0 2 7.5 1376.3 0.0 0.0 0. 0. 212.0 0.0 0.0 3 17.1 12664.2 0.0 0.0 0. 0. 1950.3 0.0 0.0 4 0.5 626.6 0.0 0.0 0. 0. 96.5 0.0 0.0 5 11.8 18288.7 0.0 0.0 0. 0. 2816.5 0.0 0.0 6 5.7 12540.2 0.0 0.0 0. 0. 1931.2 0.0 0.0 7 1.7 4410.2 0.0 0.0 0. 0. 679.2 0.0 0.0 8 14.1 50782.2 0.0 0.0 0. 0. 7820.5 0.0 0.0 9 1.4 6408.0 0.0 0.0 0. 0. 986.8 0.0 0.0 10 15.0 66770.8 0.0 0.0 0. 0. 10282.7 0.0 0.0 11 15.0 67104.9 0.0 0.0 0. 0. 10334.2 0.0 0.0 12 45.0 241591.9 0.0 0.0 0. 0. 37205.2 0.0 0.0 13 45.0 311930.2 0.0 0.0 0. 0. 48037.2 0.0 0.0 14 18.0 138922.9 0.0 0.0 0. 0. 21394.1 0.0 0.0 15 14.1 98015.3 0.0 0.0 0. 0. 15094.4 0.0 0.0 16 1.4 8446.8 0.0 0.0 0. 0. 1300.8 0.0 0.0 17 5.5 29932.7 0.0 0.0 0. 0. 4609.6 0.0 0.0 18 9.0 38192.2 0.0 0.0 0. 0. 5881.6 0.0 0.0 19 1.0 3482.4 0.0 0.0 0. 0. 536.3 0.0 0.0 20 8.8 22105.1 0.0 0.0 0. 0. 3404.2 0.0 0.0 21 7.3 5779.9 0.0 0.0 0. 0. 890.1 0.0 0.0 Failure Surface Specified By 16 Coordinate Points C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb1.OUT Page 3

Point X-Surf Y-Surf No. (ft) (ft) 1 24.83 215.00 2 25.00 214.83 3 32.53 210.30 4 49.68 200.00 5 50.22 199.70 6 67.72 190.00 7 69.44 188.27 8 83.58 174.13 9 223.02 174.47 10 237.16 188.61 11 238.55 190.00 12 244.09 200.00 13 253.10 215.00 14 254.08 217.00 15 262.85 234.98 16 270.18 250.00 Factor of Safety *** 0.997 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 25.00 215.51 2 33.67 210.30 3 50.81 200.00 4 51.36 199.70 5 68.85 190.00 6 70.67 188.18 7 84.81 174.04 8 246.65 176.62 9 260.03 190.00 10 265.57 200.00 11 274.58 215.00 12 275.56 217.00 13 284.32 234.98 14 291.65 250.00 Factor of Safety *** 0.997 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 25.00 215.51 2 33.67 210.30 3 50.81 200.00 4 51.36 199.70 5 68.85 190.00 6 70.67 188.18 7 84.81 174.04 8 246.65 176.62 9 260.03 190.00 10 265.57 200.00 11 274.58 215.00 12 275.56 217.00 13 284.32 234.98 14 291.65 250.00 Factor of Safety *** 0.997 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 28.72 215.00 2 36.54 210.30 3 53.69 200.00 4 54.24 199.70 5 71.73 190.00 6 72.77 188.96 7 86.91 174.82 8 216.38 174.66 9 230.52 188.80 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb1.OUT Page 4

10 231.72 190.00 11 237.26 200.00 12 246.28 215.00 13 247.25 217.00 14 256.02 234.98 15 263.35 250.00 Factor of Safety *** 1.007 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 28.72 215.00 2 36.54 210.30 3 53.69 200.00 4 54.24 199.70 5 71.73 190.00 6 72.77 188.96 7 86.91 174.82 8 216.38 174.66 9 230.52 188.80 10 231.72 190.00 11 237.26 200.00 12 246.28 215.00 13 247.25 217.00 14 256.02 234.98 15 263.35 250.00 Factor of Safety *** 1.007 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 29.86 215.00 2 37.68 210.30 3 54.82 200.00 4 55.37 199.70 5 72.86 190.00 6 74.00 188.87 7 88.14 174.73 8 240.01 176.81 9 253.20 190.00 10 258.74 200.00 11 267.75 215.00 12 268.73 217.00 13 277.50 234.98 14 284.82 250.00 Factor of Safety *** 1.007 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 29.86 215.00 2 37.68 210.30 3 54.82 200.00 4 55.37 199.70 5 72.86 190.00 6 74.00 188.87 7 88.14 174.73 8 240.01 176.81 9 253.20 190.00 10 258.74 200.00 11 267.75 215.00 12 268.73 217.00 13 277.50 234.98 14 284.82 250.00 Factor of Safety *** 1.007 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 28.76 215.00 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb1.OUT Page 5

2 36.58 210.30 3 53.73 200.00 4 54.28 199.70 5 71.77 190.00 6 71.79 189.98 7 85.93 175.83 8 227.02 175.30 9 241.16 189.44 10 241.72 190.00 11 247.27 200.00 12 256.28 215.00 13 257.26 217.00 14 266.02 234.98 15 273.35 250.00 Factor of Safety *** 1.010 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 28.76 215.00 2 36.58 210.30 3 53.73 200.00 4 54.28 199.70 5 71.77 190.00 6 71.79 189.98 7 85.93 175.83 8 227.02 175.30 9 241.16 189.44 10 241.72 190.00 11 247.27 200.00 12 256.28 215.00 13 257.26 217.00 14 266.02 234.98 15 273.35 250.00 Factor of Safety *** 1.010 *** **** END OF GSTABL7 OUTPUT **** RESCO; Valley Fill Stability; Section A-A'; Short-Term; Y-Acc; Block; SluryWal c:\geotechnical\saugus\2008\revised 2006 stabil\a-yacc-sb2.pl2 Run By: nk 3/12/2008 10:11AM 400 # FS Soil Soil Total Saturated Cohesion Friction Piez. Load Value a 1.00 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface Peak(A) 0.302(g) b 1.00 No. (pcf) (pcf) (psf) (deg) No. kh Coef. 0.151(g)< c 1.00 New-Ash 1 105.0 105.0 0.0 38.0 W1 d 1.00 Old-Ash 2 105.0 105.0 0.0 38.0 W1 e 1.01 MSW 3 75.0 75.0 0.0 28.0 W1 350 f 1.01 SandSilt 4 120.0 120.0 0.0 32.0 W1 g 1.01 Med-BBC 5 110.0 110.0 1000.0 0.0 W1 h 1.01 Till 6 130.0 130.0 0.0 34.0 W1 i 1.02 SluryWal 7 100.0 100.0 150.0 0.0 W1 j 1.02

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100 0 50 100 150 200 250 300 350 400 450 GSTABL7 v.2 FSmin=1.00 Safety Factors Are Calculated By The Simplified Janbu Method C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb2.OUT Page 1

*** GSTABL7 *** ** GSTABL7 by Garry H. Gregory, P.E. ** ** Original Version 1.0, January 1996; Current Version 2.003, June 2002 ** (All Rights Reserved-Unauthorized Use Prohibited) ********************************************************************************* SLOPE STABILITY ANALYSIS SYSTEM Modified Bishop, Simplified Janbu, or GLE Method of Slices. (Includes Spencer & Morgenstern-Price Type Analysis) Including Pier/Pile, Reinforcement, Soil Nail, Tieback, Nonlinear Undrained Shear Strength, Curved Phi Envelope, Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces. ********************************************************************************* Analysis Run Date: 3/12/2008 Time of Run: 10:11AM Run By: nk Input Data Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb2.i n Output Filename: C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb2.O UT Unit System: English Plotted Output Filename: C:\GEOTECHNICAL\saugus\2008\Revi2006 Stabil\a-yacc-sb2.PLT PROBLEM DESCRIPTION: RESCO; Valley Fill Stability; Section A- A'; Short-Term; Y-Acc; Block; SluryWal BOUNDARY COORDINATES 8 Top Boundaries 22 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 0.00 214.00 22.00 215.00 4 2 22.00 215.00 25.00 215.00 7 3 25.00 215.00 62.00 215.00 3 4 62.00 215.00 85.00 219.50 2 5 85.00 219.50 100.00 217.80 2 6 100.00 217.80 115.00 220.00 2 7 115.00 220.00 205.00 250.00 1 8 205.00 250.00 450.00 250.00 1 9 115.00 220.00 160.00 217.00 2 10 160.00 217.00 310.00 217.00 2 11 310.00 217.00 450.00 222.00 2 12 62.00 215.00 450.00 215.00 3 13 25.00 215.00 25.01 200.00 7 14 25.01 200.00 450.00 200.00 4 15 25.01 200.00 25.03 190.00 7 16 25.03 190.00 450.00 190.00 5 17 22.00 215.00 22.01 190.00 4 18 0.00 190.00 22.01 190.00 5 19 22.01 190.00 22.03 185.00 5 20 22.03 185.00 25.00 185.00 5 21 25.00 185.00 25.03 190.00 5 22 0.00 174.00 450.00 174.00 6 User Specified Y-Origin = 100.00(ft) Default X-Plus Value = 0.00(ft) Default Y-Plus Value = 0.00(ft) ISOTROPIC SOIL PARAMETERS 7 Type(s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 105.0 105.0 0.0 38.0 0.00 0.0 1 2 105.0 105.0 0.0 38.0 0.00 0.0 1 3 75.0 75.0 0.0 28.0 0.00 0.0 1 4 120.0 120.0 0.0 32.0 0.00 0.0 1 5 110.0 110.0 1000.0 0.0 0.00 0.0 1 6 130.0 130.0 0.0 34.0 0.00 0.0 1 7 100.0 100.0 150.0 0.0 0.00 0.0 1 Specified Peak Ground Acceleration Coefficient (A) = 0.302(g) Specified Horizontal Earthquake Coefficient (kh) = 0.151(g) Specified Vertical Earthquake Coefficient (kv) = 0.000(g) C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb2.OUT Page 2

Specified Seismic Pore-Pressure Factor = 0.000 A Critical Failure Surface Searching Method, Using A Random Technique For Generating Sliding Block Surfaces, Has Been Specified. The Active And Passive Portions Of The Sliding Surfaces Are Generated According To The Rankine Theory. 2000 Trial Surfaces Have Been Generated. 4 Boxes Specified For Generation Of Central Block Base Length Of Line Segments For Active And Passive Portions Of Sliding Block Is 15.0 Box X-Left Y-Left X-Right Y-Right Height No. (ft) (ft) (ft) (ft) (ft) 1 22.00 214.00 22.50 214.00 0.50 2 24.50 186.00 25.00 186.00 1.00 3 30.00 182.00 60.00 182.00 16.00 4 150.00 182.00 350.00 182.00 16.00 Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Evaluated. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Simplified Janbu Method * * Total Number of Trial Surfaces Evaluated = 2000 Statistical Data On All Valid FS Values: FS Max = 1.767 FS Min = 1.000 FS Ave = 1.209 Standard Deviation = 0.132 Coefficient of Variation = 10.89 % Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.36 214.93 2 22.00 214.02 3 22.10 213.91 4 24.93 185.68 5 53.62 177.60 6 347.20 174.69 7 357.81 185.29 8 362.52 190.00 9 368.06 200.00 10 375.79 212.86 11 377.07 215.00 12 379.26 219.47 13 385.83 232.96 14 392.41 246.44 15 394.14 250.00 Factor of Safety *** 1.000 *** Individual data on the 25 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 1.6 96.8 0.0 0.0 0. 0. 14.6 0.0 0.0 2 0.1 10.6 0.0 0.0 0. 0. 1.6 0.0 0.0 3 2.8 4289.7 0.0 0.0 0. 0. 647.7 0.0 0.0 4 0.1 219.5 0.0 0.0 0. 0. 33.1 0.0 0.0 5 0.0 11.4 0.0 0.0 0. 0. 1.7 0.0 0.0 6 0.0 16.1 0.0 0.0 0. 0. 2.4 0.0 0.0 7 0.0 53.7 0.0 0.0 0. 0. 8.1 0.0 0.0 8 28.6 92797.6 0.0 0.0 0. 0. 14012.4 0.0 0.0 9 8.4 30956.1 0.0 0.0 0. 0. 4674.4 0.0 0.0 10 23.0 90778.5 0.0 0.0 0. 0. 13707.6 0.0 0.0 11 15.0 61719.6 0.0 0.0 0. 0. 9319.7 0.0 0.0 12 15.0 62359.0 0.0 0.0 0. 0. 9416.2 0.0 0.0 13 45.0 229185.9 0.0 0.0 0. 0. 34607.1 0.0 0.0 14 45.0 302271.9 0.0 0.0 0. 0. 45643.1 0.0 0.0 15 105.0 796586.8 0.0 0.0 0. 0. ******* 0.0 0.0 16 37.2 285142.3 0.0 0.0 0. 0. 43056.5 0.0 0.0 17 10.6 75318.7 0.0 0.0 0. 0. 11373.1 0.0 0.0 18 4.7 29459.8 0.0 0.0 0. 0. 4448.4 0.0 0.0 19 5.5 29932.7 0.0 0.0 0. 0. 4519.8 0.0 0.0 20 7.7 33357.9 0.0 0.0 0. 0. 5037.0 0.0 0.0 21 1.3 4834.3 0.0 0.0 0. 0. 730.0 0.0 0.0 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb2.OUT Page 3

22 2.2 7505.8 0.0 0.0 0. 0. 1133.4 0.0 0.0 23 6.6 16422.4 0.0 0.0 0. 0. 2479.8 0.0 0.0 24 6.6 7114.0 0.0 0.0 0. 0. 1074.2 0.0 0.0 25 1.7 325.0 0.0 0.0 0. 0. 49.1 0.0 0.0 Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.36 214.93 2 22.00 214.02 3 22.10 213.91 4 24.93 185.68 5 53.62 177.60 6 347.20 174.69 7 357.81 185.29 8 362.52 190.00 9 368.06 200.00 10 375.79 212.86 11 377.07 215.00 12 379.26 219.47 13 385.83 232.96 14 392.41 246.44 15 394.14 250.00 Factor of Safety *** 1.000 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.36 214.93 2 22.00 214.02 3 22.10 213.91 4 24.93 185.68 5 53.62 177.60 6 347.20 174.69 7 357.81 185.29 8 362.52 190.00 9 368.06 200.00 10 375.79 212.86 11 377.07 215.00 12 379.26 219.47 13 385.83 232.96 14 392.41 246.44 15 394.14 250.00 Factor of Safety *** 1.000 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.36 214.93 2 22.00 214.02 3 22.10 213.91 4 24.93 185.68 5 53.62 177.60 6 347.20 174.69 7 357.81 185.29 8 362.52 190.00 9 368.06 200.00 10 375.79 212.86 11 377.07 215.00 12 379.26 219.47 13 385.83 232.96 14 392.41 246.44 15 394.14 250.00 Factor of Safety *** 1.000 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.95 214.95 2 22.00 214.37 3 22.28 214.09 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb2.OUT Page 4

4 24.75 185.69 5 58.89 176.16 6 338.61 175.75 7 349.22 186.36 8 352.86 190.00 9 358.40 200.00 10 366.13 212.86 11 367.42 215.00 12 369.43 219.12 13 376.00 232.60 14 382.58 246.09 15 384.49 250.00 Factor of Safety *** 1.009 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.95 214.95 2 22.00 214.37 3 22.28 214.09 4 24.75 185.69 5 58.89 176.16 6 338.61 175.75 7 349.22 186.36 8 352.86 190.00 9 358.40 200.00 10 366.13 212.86 11 367.42 215.00 12 369.43 219.12 13 376.00 232.60 14 382.58 246.09 15 384.49 250.00 Factor of Safety *** 1.009 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.95 214.95 2 22.00 214.37 3 22.28 214.09 4 24.75 185.69 5 58.89 176.16 6 338.61 175.75 7 349.22 186.36 8 352.86 190.00 9 358.40 200.00 10 366.13 212.86 11 367.42 215.00 12 369.43 219.12 13 376.00 232.60 14 382.58 246.09 15 384.49 250.00 Factor of Safety *** 1.009 *** Failure Surface Specified By 15 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.95 214.95 2 22.00 214.37 3 22.28 214.09 4 24.75 185.69 5 58.89 176.16 6 338.61 175.75 7 349.22 186.36 8 352.86 190.00 9 358.40 200.00 10 366.13 212.86 11 367.42 215.00 12 369.43 219.12 13 376.00 232.60 C:\GEOTECHNICAL\saugus\2008\Revised 2006 Stabil\a-yacc-sb2.OUT Page 5

14 382.58 246.09 15 384.49 250.00 Factor of Safety *** 1.009 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.98 214.95 2 22.00 214.39 3 22.30 214.08 4 24.87 185.82 5 45.83 174.57 6 342.13 180.41 7 351.72 190.00 8 357.26 200.00 9 364.99 212.86 10 366.28 215.00 11 368.27 219.08 12 374.84 232.56 13 381.42 246.04 14 383.35 250.00 Factor of Safety *** 1.020 *** Failure Surface Specified By 14 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 20.98 214.95 2 22.00 214.39 3 22.30 214.08 4 24.87 185.82 5 45.83 174.57 6 342.13 180.41 7 351.72 190.00 8 357.26 200.00 9 364.99 212.86 10 366.28 215.00 11 368.27 219.08 12 374.84 232.56 13 381.42 246.04 14 383.35 250.00 Factor of Safety *** 1.020 *** **** END OF GSTABL7 OUTPUT ****

Appendix B Final Cover Surficial Stability Analysis

FINAL COVER SURFICIAL STABILITY ANALYSIS

Saugus RESCO Landfill Saugus, Massachusetts

Prepared for:

June, 2008

Prepared by:

11 Northeastern Boulevard Salem, NH 03079-1953

Project 119504

Table of Contents______

List of Tables ...... i

1.0 Introduction...... 1-1 2.0 Basis and Approach...... 2-1 2.1 Final Cover Design...... 2-1 2.2 General Approach to Analysis ...... 2-2 3.0 Drainage Layer Evaluation...... 3-1 4.0 Infinite Slope Stability Analysis ...... 4-1 5.0 References ...... 5-1

List of Tables ______

Table 1 Drainage Layer Calculations – Geocomposite Transmissivity Table 2 Infinite Slope Stability Calculations

N:\projects\119504\2008\VF FEP Docs\Sum Rpt Appendix B Cvr Stab i

1.0 Introduction

In accordance with the 2008 Revisions to the Final Engineering Plan (2008 FEP), additional ash residue will be placed within the areas between ridges by flattening the cross-slope (this is referred to as the “valley fill”). The minimum cross-slope will be decreased from a five percent to a two percent slope, with a maximum side slope of three horizontal to one vertical immediately adjacent to the valley line and in the perimeter areas. The slope along the length of the valley lines will be maintained at one percent. The maximum Landfill elevation will remain at 50 feet MSL.

This report presents the results of analyses performed by Shaw Environmental, Inc. (Shaw) to evaluate the stability of the final cover and to calculate the shear strength requirement of the cover materials.

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2.0 Basis and Approach

2.1 Final Cover Design The surficial stability analysis is based on the details of the final cover design and the final slope steepness. The final cover system that will be constructed during closure of Phases III, IV, and V of the Landfill consists of four layers as follows, in ascending order:

• Subgrade Layer - Prior to the placement of the impermeable layer, the subgrade will be constructed in accordance with the FEP using ash residue or earthen materials. In accordance with the Consent Order, this minimum six-inch layer with a minimum permeability of 1 x 10-3 cm/sec will provide adequate structural support for the final cover and be free of materials which may damage or abrade the barrier layer. This layer serves the dual purposes of geomembrane bedding and venting small quantities of landfill gas to the perforated PVC gas collection and venting pipes.

• Impermeable Layer - The low permeability barrier layer will consist of a textured 40 mil high density polyethylene (HDPE) flexible membrane liner. The Consent Order allows use of a synthetic membrane as an alternative to 18 inches of low permeability (less than or equal to 1 x 10-7 cm/sec) earthen materials.

• Drainage Layer - The drainage layer of the final cover system will consist of a geocomposite drainage net that meets a transmissivity of greater than or equal to 4 x 10-3 m2/sec. The Consent Order stipulates that this layer: 1) be of sufficient thickness and hydraulic conductivity or capacity to drain the immediate and upgradient areas of the Landfill, and 2) have a hydraulic conductivity equal to 1 x 10-3 cm/sec. The geocomposite net will provide the required subsurface drainage and prevent hydraulic head buildup.

• Contingency Cap Drains – as a contingency measure to enhance subsurface drainage and slope stability, 12-inch slotted oblong corrugated polyethylene pipe cap drains will be installed on the geocomposite drainage layer and spaced across the slope every 100 horizontal feet of the two percent slopes. This will limit the build-up of vertical head to two feet to ensure cover stability.

• Vegetative Support Layer - The vegetative support layer will consist of 12 inches of a low permeability Soils Suitable to Support Vegetation (SSSV), with a hydraulic conductivity of 1 x 10-6 cm/sec or less, overlain by six inches of SSSV with a minimum organic content of nine percent. The vegetative support layer, in combination with the drainage layer, will be a minimum of 18 inches thick, in accordance with the Consent Order. The vegetative support layer will sustain a vegetative cover compatible with the area setting, having a shallow root system and capable of self-revegetation. The installed hydraulic conductivity of the 12-inch layer of low permeability soil is ten times less than the design calculation requirements to allow for long-term weathering changes to the soil matrix.

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The final cover design is illustrated in the Closure and Post-Closure Plan, Drawing No. 3. Technical Specifications for materials and closure activities are included in the Closure and Post- Closure Plan, Appendix A.

2.2 General Approach to Analysis Final cover stability is a function of the shear strength of the soils and geosynthetics and the driving slippage due to gravity forces combined with drainage head. This surficial stability analysis examines the interface strength of the final cover materials layering with respect to subsurface drainage efficiency and slope steepness. As the saturated depth in the soil increases over the liner, stability decreases. For steeper slopes, a relevant design criterion is that the saturated depth is less than the thickness of the drainage layer. This criterion is achieved by establishing a balance of infiltration rate, the hydraulic conductively of the drainage layer, the thickness of the drainage layer, the flow length to discharge, and the slope angle. Once the appropriate design balance has been achieved, the interface shear strength requirements of the final cover materials are calculated. The results are incorporated into the Technical Specifications to assure final cover stability.

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3.0 Drainage Layer Evaluation

The drainage layer for the final cover of the Landfill will be a geocomposite drain. For long uniform slopes, drainage in the drainage layer is calculated by Darcy's Law, Q= kia, where:

Q = flow (cubic feet/second, gallons/minute, liters/second, etc.)

k = the hydraulic conductivity (centimeter/sec, cubic meters/sec/ square meter, feet/day, etc.)

i = the slope gradient (percent)

a = the cross-sectional flow area (square feet, square centimeters, etc.)

The thickness of the geocomposite drain is approximately 0.028 feet. This is the maximum head on the liner if the of the geocomposite capacity is not exceeded. The hydraulic capacity of a geocomposite drain is described in terms of transmissivity at a particular gradient. Geocomposite transmissivity is typically tested at gradients of 0.1 and 0.33. Transmissivity decreases as the gradient increases, due to increase turbulence in the flow; however, overall flow capacity increases with increased gradient. Darcy's Law can be modified by combining the thickness and hydraulic conductivity into terms of the transmissivity of the layer.

The Landfill slopes are designed at a minimum of two percent and a maximum of 33 percent. The variables are the infiltration rate per unit area over the flow length per unit width and the geocomposite transmissivity. The infiltration rate will be controlled by the permeability of the overlying soil. The flow length is controlled by providing periodic cap drain discharge locations (if needed), and the geocomposite transmissivity is determined by testing and then reduced by several reduction factors and a drainage factor of safety.

The formula for allowable geocomposite transmissivity, as defined by GRI-GC8 is:

qallow = q100*[1/(FRCR*RFCC*RFBC)], where

qallow = allowable flow rate which specifies the minimum geocomposite transmissivity properties with no Drainage Factor of Safety

q100 = initial flow rate determined under simulated conditions for 100-hour duration. For design purposes, q100 is the test value of the geocomposite under design loading (x2) and design burial conditions. It adequately reflects intrusion of the geotextile and soil material into the geocomposite, and therefore includes RFIN.

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RFCR = reduction factor for creep to account for long-term behavior

RFCC = reduction factor for chemical clogging

RFBC = reduction factor for biological clogging

RFIN = reduction factor for intrusion

The Factor of Safety for Drainage (FSD) is an arbitrary value relative to the critical issues with final cover failure. An FSD equal to 2 to 3 is cited (Giroud 2006) as sufficient. GSE suggests an

FSD equal to 2 (GSE 2007).

The range of reduction factors for final cover geocomposite and the development of the Total Adjustment Factor are as follows:

Factor Low High Choice Reference

RFCR = 1.1 1.1 1.1 GSE 2007

RFCC = 1 1.2 1.2 GRI-GC8 2001

RFBC = 1.2 3.5 2 GRI-GC8 2001

RFTotal = 1.32 4.62 2.64 Use in Table 1

FSD 2 3 2 Giroud 2006 & GSE 2007 Total Adjustment 2.64 13.86 5.28 Use in Table 1 Factor

Most manufacturers' literature test specifications use ASTM D-4716 versus GRI-GC8. ASTM D-4716 is typically a 15 minute test with the sample sandwiched between two steel plates. It therefore does not reflect geotextile intrusion into the geonet core caused by softer soil adjacent to the geocomposite under field installation conditions. Intrusion then must be accounted for by

the Intrusion Reduction Factor RFIN.

Low High Choice Reference

RFIN = 1.3 1.5 NA Giroud 2006 When test RFIN = 1 1 1 includes intrusion per to GRI-GC8

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The higher RF values were mostly selected to be conservative. The highest value of biological clogging was not used due to the planned use of low permeability soils versus using sand against the geocomposite. The lower FSD value was used since the slope is non critically steep.

Table 1 presents the drainage layer calculations and results using the various reduction factors and safety factors. Based on the final cover design for the Landfill, the design drainage layer flows at two percent top slopes and 3:1 H:V side slopes are compared to the comparable flow capacities of a commercially available geocomposite product (e.g., Tenflow 7100-2©). For the top slopes, 59 percent of the rated flow capacity of the geocomposite is utilized. For the side slopes, 4 percent of the rated flow capacity is used. Thus, the commercially available products provide adequate geocomposite flow capacity. These calculations are based upon an SSSV layer hydraulic conductivity of 1 x 10-5 cm/sec. The specification requires that the lowest 12 inches of SSSV be installed with a minimum hydraulic conductivity of 1 x 10-6 cm/sec to account for long- term weathering of the soil matrix.

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4.0 Infinite Slope Stability Analysis

Final cover stability is a function of the shear strength of the soils and geosynthetics and the driving slippage due to gravity forces combined with drainage head. The shear strength of these materials is the combined strength of friction and cohesion. Often, soil cohesion is neglected as a factor in conservative design approaches. However, it may be considered in final field approval of materials, if necessary.

An infinite slope method was used to determine the stability of final cover soils because the geometry of a landfill cap is a uniform layering of materials on a long planar surface. This commonly used design evaluation method is conservative where it neglects any potential buttressing effects at the toe of slope.

Two minimum shear strengths are typically specified; one for peak shear strength and one for residual shear strength. Acceptable factors of safety (FS) against failure of 1.5 and 1.3, respectively, are commonly applied to cap designs. Failure is assumed to occur when FS is equal to or less than 1.0. This calculation is independent of the any safety or reduction factors used in the transmissivity calculations. More important is that all the cap drainage can be transmitted within the thickness of the geocomposite.

Final cover stability calculations are presented in Table 2. Based on these calculations, a minimum interface shear strength between geosynthetic materials has been determined and incorporated into the relevant Technical Specifications. If the specified interface strength cannot be achieved in pre-construction confirmatory testing, then a sand drainage layer will be used. This might only be an issue on the 3:1 H:V side slopes. If cohesion is a significant factor in the testing, then that may be considered in the stability calculations at that time.

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5.0 References

GSE. The GSE Drainage Design Manual, Second Addition, June 2007, pg 4-14, 16

GRI. GRI-GC8, Determination of the Allowable Flow Rate of a Drainage Geocomposite, Original: April 17, 2001

Giroud, J.P. Design of Geosynthetic Drainage Systems in Landfills, January 2006 (Seminar)

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Tables

Table 1 Drainage Layer Calculations - Geocomposite Transmissivity Saugus RESCO Landfill

TOP DOWN Landfill Cap Units Top Slopes @ 2% Side Slopes @ 33% Topsoil Layers (SSSV) Topsoil Topsoil Topsoil Thickness (d) ft 0.50 0.50 Topsoil Hydraulic Conductivity cm/sec 1.0E-04 1.0E-04 Saturated Depth (h) ft 0.50 0.50 Gradient (vertical i = h/d) ft 1.0 1.0 Maximum Percolation Rate ( i =1) in/hr 0.142 0.142 I = Infiltration or Percolation Inflow cf/hr/sf 0.0118 0.0118 Restrictive Layer (SSSV) Till/ SSSV Till/ SSSV Restrictive Layer Soil Thickness ft 1.00 1.00 Soil Hydraulic Conductivity cm/sec 1.0E-05 1.0E-05 Saturated Depth (h) ft - - Gradient (vertical i = h/d) unitless 1.50 1.50 Maximum Percolation Rate ( i =1) in/hr 0.021 0.021 I = Infiltration or Percolation Inflow cf/hr/sf 0.0018 0.0018 Drainage Layer Material Geocomposite Geocomposite Infiltration Rate (min. from above) cf/hr/sf 0.0018 0.0018 Design Max Flow Length to Discharge ft 340 200 Design Drainage Layer Flow cf/hr/ft 0.60 0.35 Design Drainage Layer Flow [Compare] m3/sec/m 1.55E-05 9.14E-06

Transmissivity Adjustments Geocomposite Geocomposite

Total Reduction Factor, RFtotal (see text) unitless 2.64 2.64

Drainage Safety Factor, FSd unitless 2.0 2.0 Combined Adjustment Factor unitless 5.28 5.28 s = slope, horizontal : vertical H:V 50.0 3.0 b = slope angle degrees 1.1 18.4 i = slope gradient % 2% 33%

Comparison to Products Tenflow 7100-2 Double-Sided Geocomposite - Manufacturer's Literature Geocomposite Transmissivity Data (per GRI-GC8) m2/sec 7.00E-03 4.00E-03

Intrusion Reduction Factor, RFIN (per GRI-GC8) unitless 1.00 1.00 Combined Adjustment Factor unitless 5.28 5.28 Slope and All Adjustment RFs unitless 264.0 15.8 Adj. Flow Capacity of Geocomposite [Compare] m2/sec 2.65E-05 2.53E-04 Required % of Adj. Flow Capacity % 59% 4% Max Drainage Length at 100% Capacity ft 580 5,523 Table 2 Infinite Slope Stability Calculations Saugus RESCO Landfill p Side Slopes Residual w Parameters Labels/Formula Units Top Slopes Peak Geommbrane

Slope, horzizontal : vertical S ft/ft 50.0 3.0 3.0 Slope angle B degrees 1.1 18.4 18.4 Slope in percent % 2% 33% 33% Normal to vertical slope adj. factor Adj 1.000 1.054 1.054 Soil thickness normal to the slope Hn ft 1.50 1.50 1.50 Vertical thickness of soil Tv = Hn*Adj ft 1.50 1.58 1.58 Unit dry weight of soil Gs lbs/cf 120 120 120 Vertical Dry weight of soil block Ws = Gs*Tv lbs 180 190 190 Normal depth of sat. soil (ave) Xn ft 0.028 0.028 0.028 Vertical height of water column Hv = Adj*Xn ft 0.03 0.03 0.03 Unit weight of water Gw lbs/cf 62.4 62.4 62.4 Vertical Weight of Water Gwv lbs 1.7 1.8 1.8 Total Vertical Weight lbs 182 192 192 Total Driving Force DF = Ws*SIN(b) lbs/sf 3.6 60.6 60.6

Resisting Force Minimum Factor of Safety against sliding FS 1.50 1.50 1.30 Normal soil force Ns = Ws*cos b lbs/sf 180 180 180 Pore water pressure U = Gw*Hv lbs/sf 1.7 1.8 1.8 Net normal forces N = Ns-U lbs/sf 178 178 178 Cohesion C lbs/sf 0.0 0.0 0.0 Min. interface friction angle between geocomposite and geomembrane A' degrees 1.8 27.0 23.9 Resisting friction force Frf=TAN(A')*N lbs/sf 5.5 90.9 78.8 Resiting Force, total RF = Frf + C lbs/sf 5.5 90.9 78.8

Factor of Safety FS = DF/RF 1.50 1.50 1.30