Appendix F Methane Mitigation Plan

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METHANE HAZARD MITIGATION STANDARD PLAN

I. PURPOSE

This Methane Hazard M tigation Standard Plan provides standard detailsand specifications that maybe used to comply with the requ rements of theMethane Seepage Regulations of Division 71 of the Los Angeles Build ngCode. The intent of methane mitigation systems described in this plan isto promote public safety and welfare by controlling methane intrusionemanating from geologic formations. These systems are not toregulate flammable vapors that may orig nate in and propagate from othersources, which include, but are not limited to, ruptured hazardous materialtransmission underground atmospheric tanks, or similar installations

II. THE STANDARD PLAN

The Methane testing was performed following the Site Standard Plan of the Division 71 of the Los Angeles Building Code (Form 1, Table 1A).

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III. GENERAL REQUIREMENTS

CODES:All work was performed in compliance with the current version of the Los AngelesBuilding Code and policies of the Department of Bu lding and Safety, and allapplicable County, State, and Federal Codes.

INSPECTION:All work will be subject to inspection by the Department of Building and Safety, and will be ava lable to the nspector prior to be ng covered by subsequent work

IV. MITIGATION REQUIREMENTSThe buildings is located in a Methane Zone and the mitigation procedures will comply with the Standard Plan and D vis on 71 of the Building Code

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NOTIFICATION PLACARDA permanent notification placard is required to i the presence of the Impervious Membrane. The notification placard shall be posted and maintained at the front of the building that the building is constructed with an impervious membrane. The notification placard shall be uncovered and located in conspicuous location When cast in floors, shall also remain uncovered and i a conspicuous location The lettering shall be legible from 10 feet away and at least 1inch high

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V. SpecificationsSub-Slab Vent SystemA passive vent system can be used for the project and shall cons st of perforated horizontal pipes, impervious membrane, gravel blanket under impervious membrane and around perforated horizontal pipes, and Vent Risersa. Perforated Horizontal Pipes:Perforated Horizontal Pipes shall be as minimum 3-jnch diameter Schedule 40, slotted or perforated PVC pipe or other materials approved by LADBS for the intended use.Perforated Horizontal Pipe shall be as follows:• Spacing and location of Perforated Horizontal Pipes shall be

per Table 2 on Sheet 4 of the LADBS Standard Plan • Pipes used only as vents shallbe in the horizontal position,• Undulations In the Perforated Horizontal Pipes which may impede the passage of gas, shall be avoided (e.g. Perorated Horizontal Pipes shall not be deformed to pass below

footings)b. Gravel Blanket The thickness of the gravel blanket under impervious membrane shall be per Table l A of the LADBS Standard Plan. The composition of gravel shall be washed particles that have no more than one fractured faceThe gradations of gravel and sand shall conform to Tables 3 and et 4 Standard Plan. c Gravel Thickness Around Perforated Horizontal PipesGravel thickness around Perorated Horizontal Pipes shall be per Table lA shown on Sheet 4 of the Standard Plan.When sand used as the Gravel Blanket a geofabric to prevent sand from entering the Perforated Horizontal Pipes shall be placed around the Perforated Horizontal PipesGravel shall be composed entirely of particles that have no more than one fractured face

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d Vent RisersVent Risers shall be connected to Perforated Horizontal Pipesand constructed of cast iron or any other material approved by a LARR for the intended use as methane Vent RiserVent Risers shall be spaced and located as per Table 2 on sheet of the Standard PlanVent Riser outlets shall be located as shown in Detail 12 on Sheet 8 of the standard Plan.If ra n guards are provided they shall be non-resbicting

f. Impervious Membrane Impervious Membrane Installation

Imperv ous Membrane shall be a product approved by the LADBS Engineering Research Section with a valid Los Angeles Research Report (LARR) Number. Installation shall comply with the cond t n of approval spec fied in a LARR andmanufacturers specification of the Impervious Membrane.Impervious Membrane shall be nstalled at the following locations:• Below the building slab surrounded by the inner face of the exterior footings• On the exterior surface of walls from the finished grade level to a m nimum of 6 inches below the bottom of the adjoining building slab• Around s des of pile caps and caisson caps • Impervious Membrane shall not be installed under exterior or interior footingsImpervious Membranes at elevator and sump pits shall be installed as follows:• Two layers of Impervious Membrane below slabs and footings of all elevator p ts, sump pits and hold ng tanks• Impervious Membrane does not need to be placed below elevator pistons.• Impervious Membrane shall be attached to the elevator p ston cyl nder cas ng or at the sump pit floor slab to prevent methane intrusionThe indi idual certified by the manufacturer of the Impervious Membrane shall certify on the Impervious Membrane. The completed Form 3 shall be given to the inspector prior toplacement of parts or the whole concrete floor slab.

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e. Seals at Impervious Membrane PenetrationsWhere footings, plumbing pipes, electrical conduits and other materials penetrate the Impervious Membrane, the penetrations shall be sealed by us ng sleeves or bootscomposed of the same material or other approved materials and methods in accordance with the specifications of the manufacturer for the Impervious Membrane.A gas tight seal shall be provided where the Impervious Membrane attached to all interior footings.

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8447 Olympic Blvd. Los Angeles, California

Office

Site Address: 2484 Olympic Blvd, Los Angeles CA

Description of Gas Analysis Instrument(s):

Instrument Name and Model: _Landtech GM 2000, AK-4, Barometer, Dwyer 477, FID   

City of Los Angeles Testing License #:

Instrument Accuracy: + 5                   ppmDate Time Probe Set # Concentration

(ppmv)

Pressure (inches

w ater column)

Probe Depth

(feet)

Description / Probe

Location

10/9/2015 B-1 130 0.44" w 5' NEC of proposed

building

B-2 75 0.61" w 5'

B-3 200 0.78" w 5'

B-4 230 0.78" w 5'

B-5 90 0.78" w 5'

B-6 250 0.64" w 5'

B-7 150 0.80" w 5'

10/11/2015 B-3 370 0.78" w 5'

B-3 330 0.64" w 10'

B-3 170 0.61" w 20'

B-4 220 0.71" w 5'

B-4 240 0.74" w 10'

B-4 320 0.64" w 20'

B-6 450 0.80" w 5'

B-6 380 0.67" w 10'

B-6 340 0.67" w 20'

NA>100

4500.8

<2

Amir Rouhani

5518 Paseo Del Lago, #2ELaguna Woods, CA 92637

Date 10/9/2015

Time

Presure

mm Hg

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8:30 759

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Atmospheric Pressure

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P/BC 2004-102

As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.

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2" thick sand layer above visquene (to protect Visquene)

4" dia. Perforated Horizontal Vent Pipe (length shall be equal to length of the addition)

2" thick Gravel under Visquene

6 mil. thick Visquene

2" thick Gravel around Perforated Horizontal Vent Pipe

Finished concrete slab

Detail 1 - Typical Cross Section

Note: 1. If groundwater is found during footing excavation, then special approval from the Department of Building and Safety is required for dewatering. 2. Gravel shall be clean crushed rock with maximium particle size of 3/8" and less than 10% passing sieve No. 8. 3. Sand shall be clean sand with less than 10% passing Sieve No. 100.

Gravel layer

Sand layer to protect Visquene

Visquene

Polypropylene cable tie 2" min. above base penetration

Conduit or pipe penetration

Overlap Visquene on pipe

Subgrade

3" min. collar extendsinto concrete

3" min.

16" min.Typ.

Detail 2 - Visquene Penetration

P/BC 2004-102

As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.

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Detail 3 - Visquene Overlap

Detail 4 - Visquene Termination at Exterior Footing

Sand layer toprotect Visquene

Gravel layer

6 mil thick Visquene

Finished concrete slab

2'-0" Overlap

Visquene

Sand layer toprotect Visquene

Gravel layer

Visquene termination point at bottom of footing

Optional cold joint

P/BC 2004-102

As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.

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Detail 5 - Perforated Horizontal Vent Pipe andVisquene at Interior Footing

Visquene

Optional cold joint

Provide adequate support for vent piping during concrete pour

4" dia. perforated Horizontal Vent Pipe

Polypropylene cable tie to hold 2" min. edge of Visquene

4" dia. Perforated Horizontal Vent Pipe

4" 4" Footing Sleeve through footing

Wall

Slab

P/BC 2004-102

As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.

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Vent Riser clamp or strap (typ.)

Vent Riser inside wall:residential buildings up to 2 stories may use PVC, cast iron, galvanized steel, black iron or PVDF pipes as Vent Riser orfor all other buildings, Vent Riser shall be of cast Iron, galvanized steel, or PVDF pipe.

Placard

Rain guard (non-restricting type)

2nd floor

3' min. clearance above highest point of roof within a 10' radius of outlet,See Note 1.

Perforated Horizontal Pipe

Approved adaptor (Fernco )

Cast Iron Pipe

No-hub coupling

6" Min.

10'-0" min.

CAUTION

METHANE GAS IN PIPENO SMOKING

OR ELECTRICAL EQUIPMENT WITHIN 10'

Notes for placard sign: 1. 3" x 4" wide, 2. Plastic with adhesive backing, and 3. 3/8" high black letters on white background

Placard sign, spaced at 5' interval (typ.)

Detail 6 - Vent Riser

1st floor

3rd floor

Attic space

6" min.

Notes:

1. Termination of Vent Riser shall be as follows: a. 10' min. above grade, b. 10' min. away from any window, door, door hatch, opening or air intake into the building, c. 3' min. above highest point of roof within a 10' radius of outlet, d. 4' min away from property line, and e. 5' min. away from eletrical devices.2. Wrap and protect all piping through concrete slab or floor.3. Support all piping per Table 3-2 of Los Angeles Plumbing Code.

P/BC 2004-102

As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.

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Detail 7 - Conduit Seal

Sealing compound

EYS vertical

Fiber filler

Conduit

Veritcal Conduit Seal

Horizontal Conduit Seal

Fiber Filler

Sealing compound

Fiber Filler

Circuit Breaker Panel

Conduit joint

Slab

Fill thickness equal to conduit diameter not less than 5/8")

WYE Seal

x

> x

P/BC 2004-102

As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.

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Detail 8 - Trench Dam

Section:Impervious Membrane

Gravel Blanket under membrane

SubgradeTrench

Finished grade

Sand backfill Trench Dam (See Note #2)

Plan View:

Pipe or conduit(See Note #4)

Slab

Backfillbelow slab level

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Sand backfill

Pipe or conduit

1. All Trench Dams shall be installed in trenches containing piping and conduit that connects directly from the utility lines in the street.2. The width of a Trench Dam shall be one half the length.3. Trench Dams shall be constructed of one of the following: a. Bentonite Cement Slurry three feet long: A mixture of 4% Type II Cement, and 2% Powdered Bentonite. b. Compacted Native Soils Backfill five feet long: Native soils shall be compacted at least 90% relative compaction in accordance with ASTM D-1557 Testing Procedures. c. Concrete mixes other than Bentonite Cement Slurry may be used provided conduit or piping is wrapped with High Density PVC Foam Tape, Closed Cells, Adhesive Backed, 1/4" thick by ½" wide shall be applied to clear surface with ends butted together at most visible locations in Trench Dam.4. Piping and conduit shall be protected from corrosion and structural settlement as follows: a. Tape shall be applied on conduit and piping encased in cement slurry or concrete. b. Tape shall be PS-37-90, Black Plastic PVC or PE Pressure-Sensitive Corrosion Preventive Tape.

Notes: Trench Dams

6"

4" min.

Trench Dam Length(See Notes #3 a and b)

Trench Dam Length(See Notes #3 a and b)

Trench Dam (See Notes #3 a and b)

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