20089_Durham Collision_VIMS Modification_2021.10.04

2501 Blue Ridge Road, Suite 430 Raleigh, North Carolina 27607 PH 919.870.0576 www.geosyntec.com

15 July 2021
VIA E-MAIL

Mr. J. Kevin Slaughter
Project Manager, Brownfields Property Management Unit
NCDEQ - Division of Waste Management
217 West Jones Street
Raleigh, NC 27603

RE: VIMS Modification Request Letter – REV 1
Former Durham Collision Center
510 East Pettigrew Street
Durham, Durham County, North Carolina
NCBP Project No. 20089-16-032
Geosyntec Project No. GN7163

Dear Mr. Slaughter:

On behalf of PGD Pettigrew Gateway, LLC (Prospective Developer), Geosyntec Consultants of
NC, P.C. (Geosyntec) has prepared, for your review and approval, this letter detailing the
modifications to the vapor intrusion (VI) mitigation system (VIMS) design at the former Durham
Collision Center located at 510 East Pettigrew Street in Durham, Durham County, North Carolina
(herein referred to as the “Subject Site” or “Site”). The Subject Site is identified as the Former
Durham Collision Center by the North Carolina Brownfields Program (NCBP) under Project ID
20089-16-032. The Site is subject to a Notice of Brownfields Property dated 25 April 2018 and an
associated Brownfields Agreement (BFA).

Proposed redevelopment of the Brownfields Property includes the construction of a high-rise
apartment building with a two-deck parking structure (first level parking below grade and second
level parking at grade). A VIMS was designed to mitigate potential VI risk concerns in connection
with constituents of potential concern (COPCs). The apartment building’s design calls for the
majority of the space directly above the slab-on-grade (SOG) to be open parking garages in
connection with ambient outdoor air; therefore, the VIMS is not designed below the open parking
garages. Rather, the VIMS design targets specific portions of the apartment’s footprint that are
not open and will be occupied for use by residents and maintenance personnel (including elevators
and stairwells). Details of the VIMS design are provided in the Vapor Intrusion Mitigation System
Design Report (Geosyntec, October 2020) which was approved by NCBP on 23 October 2020.
Mr. J Kevin Slaughter 15 July 2021
Page 2

Proposed modifications to the VIMS are described below. The modifications address field
conflicts, building design modifications, and support construction planning. Please note that this
letter summarizes previous correspondence regarding modifications to the VIMS:

• Vapor Monitoring Point Construction: The construction of the vapor monitoring points
(VMPs) will be revised from those shown on Details 1-V10 and 2-V10 (Attachment A).
In place of the proposed VMPs, a Vapor Pin® Insert will be installed. The Vapor Pin Inset
is product manufactured by Vapor Pin Enterprises that can be installed directly into the
VIMS’ geomembrane to “facilitate the collection of soil gas samples and pressure
measurements beneath engineered vapor intrusion barriers…” Details are provided on the
“Standard Operating Procedure Installation of the Vapor Pin Insert” provided in
Attachment B. NCBP provided verbal approval for this modification on 9 November
2020.
• VMP-17 Location: The final design of the apartment building included an access door to
the room that VMP-17 was proposed to monitor with extension tubing (Drawing V3 and
Detail 2-V10; Attachment A). Due to this change, extension tubing does not need to be
installed, and VMP-17 can be installed directly at the monitoring location, without
extension tubing. NCBP provided verbal approval for this modification on 9 November
2020.
Furthermore, the sampling and analysis plan will be revised to include VMP-17 and
exclude VMP-05 during pre- and post-occupancy sub-slab soil gas sampling events. A
summary of the VMP locations and the sampling and analysis plan is provided as Table 1.
• Elevator Pit: The construction method employed to pour the elevator pits did not allow
the VIMS to be installed as designed (Detail 1-V7; Attachment A). During the pouring of
the concrete for the elevator pit, the foundation footers in the area were poured at the same
time, such that a single, monolithic concrete structure was constructed. This did not allow
for the inclusion of a geomembrane below each elevator pit; however, geomembranes were
able to be installed along the vertical walls of the elevator pit. In the areas immediately
underneath and around the elevator pits, #57-stone aggregate was installed (as shown on
Construction Details 5-A7.11 and 5-A7.12; Attachment A), which should allow for
vacuum propagation below the elevator pits.
The VIMS design will be modified to include the installation of a vapor barrier on the
interior of the elevator pit. Retro-Coat® VI coating (a Land Science product), was selected
as the interior vapor barrier. Retro-Coat is a roll-applied VI coating system that will block

Tables
TABLE 1
VAPOR MONITORING POINT SAMPLING AND ANALYSIS PLAN
FORMER DURHAM COLLISION CENTER
510 E PETTIGREW STREET
DURHAM, NORTH CAROLINA
NCBP PROJECT NUMBER 20089-16-32
Suction Point
Area VMPs Location of VMP Subslab Soil
Gas Sample
SP-01 VMP-06 Stairwell 1 X
SP-02 VMP-07 Stairwell 2 X
VMP-01 Tenant Storage
VMP-02 Pool Equipment X
VMP-03 Move-in Room
VMP-08 Stairwell 3 X
VMP-04 Bike Room X
VMP-05 Electrical Room
VMP-17 Pump Room X
SP-05 VMP-16 Move-in Room X
VMP-09 Trash Room
VMP-10 Trash Room X
VMP-11 Bedroom
VMP-12 Work/Breakroom X
VMP-13 Lounge X
VMP-14 Lounge
VMP-15 Leasing Office
Notes:
1. VMP indicates vapor monitoring point.
2. Location of VMP indicates the area of the structure each VMP is located within.
SP-07 and
SP-08
3. Subslab soil gas samples will be analyze for volatile organic compounds (VOCs) using
Environmental Protection Agency (EPA) Method TO-15 (full list).
SP-04
SP-06
SP-03
1 of 1

Attachment A
Select Design Drawings
VMP-01VMP-02VMP-03VMP-04VMP-17VMP-06VMP-08VMP-01-16EXTENT OF VAPOR INTRUSION MITIGATION AREAVIMS VENT MATTINGVERTICAL VENT MATTING4" DIA. VIMS TRANSFER PIPING BELOW GRADELEGEND4" DIA. VIMS TRANSFER PIPING ABOVE GRADESUCTION POINT AND RISER TO ROOFRISER PIPING ONLY (TO ROOF)SUCTION POINT TO ABOVE GRADE TRANSFERPIPINGVIMS MONITORING POINTVIMS MONITORING POINT EXTENSION2V62V62V62V62'2'2'6'4'2'2'2'5'2'2'7'7'5'13'6'8'14'21'30'28'21'9'2'1V72V82V82V61V103'2'3'VMP-072'3'2'3'2'25'VMP-05VMP-169'5'4'3'RISER TO ROOFFROM P-21V65'3'2'4'2V10VMP-174V102V63V87V107V104V102V82V5TYP.1V62V82V82V71V54V52V72V82V72V5SP-05 VERTICAL RISER TO CONNECT TO ABOVEGRADE TRANSFER PIPING AT P-2. INSTALL TRANSFERPIPING FROM SUCTION POINT TO RISER INACCORDANCE WITH TECHNICAL SPECIFICATIONS3V8TYP.5V102V5TYP.TYP.TYP.2V92V9VIMA-01 ANDSP-01VIMA-02 ANDSP-02VIMA-03 ANDSP-03VIMA-04 ANDSP-041V8VIMA-05 AND SP-053V6ABOVE GRADETRANSFER PIPINGLOCATED ON P-2 CEILINGSP-04 VERTICAL RISERTO CONNECT TOABOVE GRADETRANSFER PIPING ATP-2 CEILINGRISER PIPE (TO ROOFFROM P-2) FOR SP-057'8'9'13'6'8'8'5'5'7'7'5'5'© 2020 CLINE DESIGN ASSOCIATES, PA EXPRESSLY RESERVES ITS COMMON LAW COPYRIGHT AND OTHER PROPERTY RIGHTS IN THESE PLANS. THESE PLANS ARE NOT TO BE REPRODUCED, CHANGED OR COPIED IN ANY FORM OR MANNER WHATSOEVER, NOR ARE THEY TO BE ASSIGNED TO ANY THIRD PARTY WITHOUT FIRST OBTAINING THE EXPRESSED WRITTEN PERMISSION AND CONSENT OF CLINE DESIGN ASSOCIATES, PA.DRAWN BY:CHECKED BY:REVISIONS:DATE:PROJECT:125 N. Harrington St.Raleigh, NC 27603919/833-6413ClineDesignAssoc.comGMP/PERMIT SETPARK GROVE REALTY/ DIMARCO GROUP510 EAST PETTIGREW APARTMENTSDurham, NCMJ, MB, EL018182RMKOCTOBER 2020CONSTRUCTIONDOCUMENTS1SEE DRAWING V4 FOR UPPER LEVEL OF FOUNDATION PLAN (P-2)LOWERFOUNDATION (P-1)VIMS LAYOUTV3N- The area VMP-17 is monitoring can now bedirectly accessed for field readings; therefore,the monitoring point extension will be revised.- VMP-17 will be installed at the location wheremonitoring point extension previouslyterminated, shown here, with a purple dot.- The monitoring point extension is no longernecessary, and it will not be installed (ascrossed out with a black line)The monitoring point extension will no longerbe required since VIMS Monitoring PointVMP-17 can be installed at the location it isintended to monitor.
GEOMEMBRANE(15-MIL STEGO OREQUIVALENT)6" 57 STONEAGGREGATE (TYP)NON-WOVEN GEOTEXTILENOTE1. MINIMUM 6-IN CONTINUOUSSEAL TO CONCRETEFOUNDATION REQUIRED(E.G. STEGO CRETE CLAW)SEE NOTE 1SUBGRADE BY OTHERSGEOMEMBRANE (15-MIL STEGOOR EQUIVALENT) SEE NOTE 1VENT MATTING (TERRAVENT OREQUIVALENT) SPACED 3-FT ONCENTER; MIN. 1-FT HORIZONALUNDER SLAB6" 57 STONEAGGREGATE (TYP)6" 57 STONEAGGREGATE (TYP)NON-WOVEN GEOTEXTILENOTE1. SEE STRUCTURAL DESIGN FOR WATERPROOFING REQUIREMENTSNON-WOVEN GEOTEXTILEGEOMEMBRANE(15-MIL STEGOOR EQUIVALENT)6" 57 STONEAGGREGATE (TYP)NON-WOVEN GEOTEXTILENOTE1. MINIMUM 6-IN CONTINUOUSSEAL TO CONCRETEFOUNDATION REQUIRED(E.G. STEGO CRETE CLAW)SEE NOTE 1SUBGRADE BY OTHERSGEOMEMBRANE(15-MIL STEGOOR EQUIVALENT)6" 57 STONEAGGREGATE(TYP)NON-WOVENGEOTEXTILESUBGRADEBY OTHERSNOTE1. MINIMUM 6-IN CONTINUOUSSEAL TO CONCRETEFOUNDATION REQUIRED(E.G. STEGO CRETE CLAW)SEE NOTE 1© 2020 CLINE DESIGN ASSOCIATES, PA EXPRESSLY RESERVES ITS COMMON LAW COPYRIGHT AND OTHER PROPERTY RIGHTS IN THESE PLANS. THESE PLANS ARE NOT TO BE REPRODUCED, CHANGED OR COPIED IN ANY FORM OR MANNER WHATSOEVER, NOR ARE THEY TO BE ASSIGNED TO ANY THIRD PARTY WITHOUT FIRST OBTAINING THE EXPRESSED WRITTEN PERMISSION AND CONSENT OF CLINE DESIGN ASSOCIATES, PA.DRAWN BY:CHECKED BY:REVISIONS:DATE:PROJECT:125 N. Harrington St.Raleigh, NC 27603919/833-6413ClineDesignAssoc.comGMP/PERMIT SETPARK GROVE REALTY/ DIMARCO GROUP510 EAST PETTIGREW APARTMENTSDurham, NCMJ, MB, EL018182RMKOCTOBER 2020CONSTRUCTIONDOCUMENTS11SCALE: N.T.S.XREF: XR 0050 DETAILSECTION THROUGH ELEVATOR PITV3VIMS DETAILSADAPTED FROMSTRUCTURAL DETAILSV7STRUCTURAL DETAILCALL OUT AND TITLETYPICAL ALL DETAILS2SCALE: N.T.S.XREF: XR 0050 TYPICAL DETAILS REPRESENTING "COMPARABLE" FOUNDATION FEATURES (SEE NOTE BELOW)EDGE OF BUILDING WITHOUT RETAINING WALLV3NOTE:DETAILS PROVIDED ARE NOT EXHAUSTIVE OF EDGES OF BUILDING WITHOUT RETAINING WALLS.DETAILS PROVIDE EXAMPLES OF HOW TO INCORPORATE VIMS COMPONENTS INTO "COMPARABLE"DESIGN ELEMENTS.0The elevator pit was poured at the same time asfoundation footers creating a single, monolithic,concrete structure. Therefore, the geomembranecould not be installed beneath it as originallyproposed (crossed out in black)RetroCoat vapor intrusion coating (a LandScience product; teal line) will be roll applied onthe interior of the elevator pit, at least 4 inchesabove the base of the elevator pit.
WALL OR COLUMN4" SCH 40 PVCRISER PIPEFROM SUB-SLABRISER PIPESUPPORT CLAMP(SEE NOTE 1)TO ROOFNOTES:1. VERTICAL PIPE RUNS SHALL BESUPPORTED AT LEAST EVERY 10 FEETAND AT EVERY PENETRATIONTHROUGH SLABS, CEILINGS, OR ROOFDECKS, IN ACCORDANCE WITH LOCALBUILDING CODES2. MARK OR LABEL EACH RISER PIPE ATMAXIUM 10' SPACING TO READ ASFOLLOWS: "VAPOR MITIGATIONSYSTEM: CONTACT MAINTENANCE TOREPORT DAMAGE"LABEL PIPE (NOTE 2)PIPE HANGERFOR 4" PVC (SEENOTE 2) (TYP.)CEILINGSLOPE PIPE BACK TOWARDVERTICAL RISER AT 1/8-INCH PERFOOT (1 PERCENT)WALL OR COLUMN4" SCH 40 PVCRISER PIPEFROM SUB-SLABTO ROOFRISER PIPESUPPORT CLAMP(SEE NOTE 1)4" SCH 40 PVCSWEEP ELBOWNOTES:1. VERTICAL PIPE RUNS SHALL BE SUPPORTED AT LEAST EVERY 10 FEET AND AT EVERY PENETRATIONTHROUGH SLABS, CEILINGS, OR ROOF DECKS, AND IN ACCORDANCE WITH LOCAL BUILDING CODES.2. HORIZONTAL RUNS SHALL BE SUPPORTED AT LEAST EVERY 6 FEET WITH CODE APPROVED HANGERS.3. MARK OR LABEL EACH RISER PIPE AT MAXIUM 10' SPACING TO READ AS FOLLOWS: "VAPOR MITIGATIONSYSTEM: CONTACT MAINTENANCE TO REPORT DAMAGE"4" SCH 40PVC SWEEPELBOWLABEL PIPE (NOTE 3)FROM SUB-SLABDWYERMANGNEHELICGAUGE (2005)4" PVC PIPETO ROOFFROM SUB-SLAB4" PVC PIPETO ROOFVACUUM PORT - BRASS FITTING(14" MALE NPT X 14" BARBED)14" KURI TEC CLEARBRANDVACUUM MONITORINGTUBING (OR EQUIVALENT)MOUNTINGSTAP (TYP)MOUNTINGSTAP (TYP)4-20mA 2 WIRE,IN CONDUITTO FIREALARM PANELDWYER 668PRESSURETRANSMITTER(0 TO 5 IN WC)BARBED TEECONNECTIONVALTERRA GATEVALVE (PART NO. 6401)MAGNEHELIC GAUGEINSTALLED MIN 5-FTFROM TOP OFCONCRETE SLABVALTERRA GATEVALVE INSTALLEDMIN 7-FT FROM TOPOF CONCRETE SLABAND AMENABLE TOMAINTENANCEFRONT VIEWSIDE VIEW - A6" #57 STONEAGGREGATE(TYP)3V103V102' MIN.2' MIN.6" MIN.NOTE:1. VENT MATTING CONNECTION SHALL BE INSTALLED WITHIN THE SUCTION RISER NOTCH SUCH THAT THEPERMABLE SIDE OF THE VENT MATTING IS DIRECTED UPWARDS, INTO THE NOTCH AND TOWARD THEGEOMEMBRANE.2. VENT MATTING CONNECTION AND PRIMARY VENT MATTING EXTRACTION LINE SHALL HAVE A MINIMUMOVERLAP IN ACCORDANCE WITH MANUFACTURER REQUIREMENTS.3. PRIMARY VENT MATTING EXTRACTION LINE SHALL BE INSTALLED WITH THE PERMEABLE SIDE DIRECTEDDOWNWARD, TOWARD THE PERMEABLE SIDE OF THE VENT MATTING CONNECTION STRIP.TOP VIEW6" MIN.SIDE VIEW A6" #57 STONEAGGREGATE(TYP)GEOMEMBRANE (15 MILSTEGO OR EQUIVALENT)4" SCH 40 PVC TEECONCRETESLABCOMPACTED FILLSUBGRADE1-FT WIDE NOTCH IN 4"PVC, (NOTCH 2" DEEP)4" PVC CAP (TYP)4" SCH 40 PVC RISER PIPE4" SCH 40 PVC TEECONCRETE SLABCOMPACTED FILLSUBGRADE4" SCH 40 PVC RISER PIPENON WOVEN GEOTEXTILEPRIMARY VENT MATTINGEXTRACTION LINE (TERRAVENTOR EQUIVALENT) (NOTE 3)NON WOVEN GEOTEXTILEMEMBRANE PENETRATIONMEMBRANE PENETRATIONTO ROOFTO ROOFGEOMEMBRANE (15 MILSTEGO OR EQUIVALENT)VENT MATTING CONNECTION(TERRAVENT OR EQUIVALENT)(NOTE 1 AND 2)VENT MATTING CONNECTION(TERRAVENT OR EQUIVALENT)(NOTE 1 AND 2) TYP.PRIMARY VENT MATTINGEXTRACTION LINE (TERRAVENT OREQUIVALENT) (NOTE 3)4" SCH 40 PVC TEE4" SCH 40 PVC RISER PIPE4" PVC CAP (TYP)PRIMARY VENT MATTINGEXTRACTION LINE(TERRAVENT OREQUIVALENT) (NOTE 3)VENT MATTING CONNECTION(TERRAVENT OR EQUIVALENT)(NOTE 1 AND 2)1-FT WIDE NOTCH INBOTTOM OF 4" PVC (TYP)VENT MATTING CONNECTIONUNDER 4" PVC PIPE NOTCH (TYP)2' MIN2' MIN6V106V106" MIN.EXTEND VENT MATTINGEXTEND VENTMATTING (TYP)1-FT WIDE NOTCH IN 4"PVC, (NOTCH 2" DEEP)LABEL PIPE(SEE NOTE 1)LABEL PIPE(SEE NOTE 1)GEOMEMBRANE (15 MILSTEGO OR EQUIVALENT)CONCRETE SLABCOMPACTED FILLSUBGRADEPIPENON WOVEN GEOTEXTILE3" MINIMUM COLLAREXTENDS INTO CONCRETEGAS TIGHT BOOT OR OTHERAPPROVED SEAL(BUTYL ADHESIVE TABE, STEGOTAPE OR STEGO MASTIC)3" MINPOLYPROPYLENE CABLE TIE ORTAPE OR MASTIC 2" MIN ABOVEBASE PENETRATION AS PERMANUFACTURERS'SSPECIFICATIONSNOTE1. WHERE FOOTINGS PLUMBING PIPES, ELECTRICAL CONDUITS OR OTHER MATERIALS PENETRATETHE GEOMEMBRANE VAPOR BARRIER, THE PENETRATIONS SHALL BE SEALED USING SLEEVESOR BOOTS COMPOSED OF THE SAME MATERIAL OR OTHER APPROVED MATERIALS ANDMETHODS (SUCH AS BULYT ADHESIVE TAPE, STEGO TAPE OR STEGO MASTIC) IN ACCORDANCEWITH THE SPECIFICATIONS OF THE GEOMEMBRANE VAPOR BARRIER MANUFACTURER.2. NO PENETRATIONS OF ANY KIND (E.G. PLUMBING, ELECTRICAL, ETC.) SHALL BE PERMITTEDTHROUGH THE VENT MATTING3" MIN6" #57 STONE AGGREGATE6" #57 STONEAGGREGATE (TYP)1" SCH 40 PVC PIPEEMCO WHEATON 8”X 8” MONITORING WELLROUND MANHOLE (OR EQUIVALENT)THREADED PVC CAP2" CONCRETECONCRETE SLABGEOMEMBRANE (15 MILSTEGO OR EQUIVALENT)NON WOVEN GEOTEXTILE14" O.D. NYLAFLOW TUBINGPOLYURETHANE CAULKAPPLIED AROUNDNYLAFLOW TUBE14" F/F NPT BRASS BALL VALVEWITH TEE HANDLE ANDCOMPRESSION FITTINGS2" (MIN.)2" (MIN.)SUBGRADE1" PVC ELBOW(THREADED FITTINGS)1" PVC CAP WITH 516" HOLE(TYP.) WITH POLYURETHANECAULKGEOPROBE AT86 SOILVAPOR IMPLANT WITHPOINT (TYP.)NOTES:1. A MINIMUM OF 2-INCHES OF GRAVEL SHALL BE PLACED AROUND THE ENTIRETY OF THE 1-INCHDIAMETER SUB-SLAB PRESSURE MONITORING CONDUIT.2. USE THREADED FITTINGS TO ASSEMBLE PVC ELEMENTS TO THE MONITORING PROBE.MEMBRANE PENETRATION3V106" #57 STONEAGGREGATE (TYP)NON WOVENGEOTEXTILE(TYP)EMCO WHEATON 8”X 8” MONITORING WELLROUND MANHOLE (OR EQUIVALENT)2" CONCRETECONCRETE SLABGEOMEMBRANE (15 MILSTEGO OR EQUIVALENT)NON WOVENGEOTEXTILENOTES:1. A MINIMUM OF 2-INCHES OF GRAVEL SHALL BE PLACED AROUND THE ENTIRETY OF THE 1-INCHDIAMETER SUB-SLAB PRESSURE MONITORING CONDUIT.2. USE THREADED FITTINGS TO ASSEMBLE PVC ELEMENTS TO THE MONITORING PROBE, UNLESSOTHERWISE SPECIFIED.SUBGRADE2" (MIN.)2" (MIN.)1" PVC CAP WITH 516" HOLE(TYP.) WITH POLYURETHANECAULK (TYP)GEOPROBE AT86 SOILVAPOR IMPLANT WITHPOINT (TYP.)1-INCH DIA. PVCCONDUIT (TYP)MEMBRANE PENETRATION3V101" PVC ELBOW(THREADED FITTINGS)POLYURETHANE CAULKAPPLIED AROUNDNYLAFLOW TUBE14" F/F NPT BRASS BALL VALVEWITH TEE HANDLE ANDCOMPRESSION FITTINGSTHREADED PVC CAP1-FT14" O.D. NYLAFLOW TUBING3V102'GEOMEMBRANE (15 MILSTEGO OR EQUIVALENT)4" SCH 40PVC ELBOWCONCRETE SLABCOMPACTED FILLSUBGRADE4" SCH 40 PVC WITH PERFORATIONS(PERFORATIONS FACING DOWN)4" SCH 40 PVC RISER PIPENON WOVEN GEOTEXTILEMEMBRANE PENETRATION4" SCH 40 PVCTRANSFER PIPETRANSFER PIPETO TERRAVENTTERMINATION6V10© 2020 CLINE DESIGN ASSOCIATES, PA EXPRESSLY RESERVES ITS COMMON LAW COPYRIGHT AND OTHER PROPERTY RIGHTS IN THESE PLANS. THESE PLANS ARE NOT TO BE REPRODUCED, CHANGED OR COPIED IN ANY FORM OR MANNER WHATSOEVER, NOR ARE THEY TO BE ASSIGNED TO ANY THIRD PARTY WITHOUT FIRST OBTAINING THE EXPRESSED WRITTEN PERMISSION AND CONSENT OF CLINE DESIGN ASSOCIATES, PA.DRAWN BY:CHECKED BY:REVISIONS:DATE:PROJECT:125 N. Harrington St.Raleigh, NC 27603919/833-6413ClineDesignAssoc.comGMP/PERMIT SETPARK GROVE REALTY/ DIMARCO GROUP510 EAST PETTIGREW APARTMENTSDurham, NCMJ, MB, EL018182RMKOCTOBER 2020CONSTRUCTIONDOCUMENTS12SCALE: N.T.S.XREF: XR 0050 DETAILVAPOR MONITORING PROBE WITH EXTENSION: VMP-17V33SCALE: N.T.S.XREF: XR 0050 TYPICAL DETAILMEMBRANE PENETRATIONV64SCALE: N.T.S.XREF: XR 0050 DETAILVIMS RISER (TYP) - VERTICAL ONLYV35SCALE: N.T.S.XREF: XR 0050 DETAILVIMS RISER (TYP) - VERTICAL AND HORIZONTALV36SCALE: N.T.S.XREF: XR 0050 DETAILVACUUM MONITORING GAUGE AND PRESSURE TRANSMITTERV10VIMS PIPING ANDMONITORING SYSTEMDETAILSV107SCALE: N.T.S.XREF: XR 0050 DETAILSUCTION POINTS WITH RISER CONNECTIONV39SCALE: N.T.S.XREF: XR 0050 DETAILTYPICAL RISER PIPE ROOF PENETRATIONTYP.1SCALE: N.T.S.XREF: XR 0050 DETAILVAPOR MONITORING PROBE: VMP-01 THROUGH VMP-16V38SCALE: N.T.S.XREF: XR 0050 DETAILSUCTION POINT WITH BELOW GRADE TRANSFER PIPEV40Vapor Monitoring Probe designs arebeing updated. They will now consistof a Vapor Pin Insert that is installedprior to the slab being poured. AVapor Pin will then be installed intothe Vapor Pin Insert for monitoringpurposes. A figure depicting themonitoring probe and the installationprocedure is provided inAttachmentB.The extension for Vapor MonitoringProbe (VMP-17) is no longer requiredas the area it is monitoring can nowbe directly accessed for fieldreadings. Therefore, VMP-17 can beinstalled at the proposed locationwith no modifications.
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Attachment B

Product and Material Information
1 © 2016 Land Science Technologies
Land Science Technologies
Specifications for Retro-Coat™ Version 1.0
Part 1 – Scope
1.1 Product and Application
This specification describes the application of the Retro-Coat™ System. The minimum thickness of the system is between 25-30 mils, including a 20 mil minimum application of Retro-Coat.
1.2 Acceptable Manufacturers
A.Retro-Coat as manufactured by Land Science Technologies San Clemente, CA.
1.3 Performance Criteria
A.Retro-Coat as manufactured by Land Science Technologies San Clemente, CA.
1.Diffusion Coefficient (Columbia Labs)PCE: 7.6 x 10-14 m2/s TCE: 8.2 x 10-14 m2/s
2.Tensile Elongation (ASTM D-638)Minimum: 6000 psi
3.Tensile Elongation (ASTM D-638)Minimum: 6 %
4.Flexural Strength (ASTM D-790)Minimum: 7000 psi
5.Hardness, Shore D (ASTM D-2240)
Maximum: 85
6.Gardner Impact (ASTM D-2794)Minimum: 80 inch-pounds
7.Bond Strength to Quarry TileMinimum: 1000 psi
8.Vapor Transmission Rate (ASTM E-96)Maximum: .07 perms
9.Water Absorption (ASTM D-570)Maximum: .02% in 24 hours
10. 60° GlossMinimum: 100.
1.4 Materials
A.Retro-Coat “A” shall be a modified epoxy containing special flexibilizers and specially formulated resins forsuperior chemical resistance and enhanced resilience. No solvents are allowed.
B.Retro-Coat “B” shall be customized blend of hardeners specifically formulated to maximize chemical resistance.No solvents are allowed.
1.5 Applicator
A.Applicator must be a certified contractor of Land Science Technologies.
2 © 2016 Land Science Technologies
Part 2 – Application
2.1 Surface Preparation
A.All existing surfaces that will be covered with the systems specified herein should be mechanically ground, shotblasted or sand blasted to yield a minimum 60 grit surface texture. All loosely adhered coatings will beremoved. Any grease and other contaminants found on the concrete must also be removed.
B.All open cracks 1/2” and greater should be v-notched to a 3/4” width by 1/2” depth and cleaned of any debris.Such cracks should be filled with Retro-Coat Gel and struck off flush with the surrounding surface.
C.Cut back and/or remove any expansion joint backing or filler strips to a minimum of 1 ½” deep. Insertdisposable filler in the joints to prevent filling with the overlayment materials and to allow for accurate location offinal saw cuts in the overlayment.
2.2 Material Application
A.Retro-Coat CAULK
1.Apply Retro-Coat CAULK around the base of all pipe penetrations making sure to fill any gap between the
penetration and concrete slab
2.Apply Retro-Coat CAULK to the joint created between horizontal and verticaltransitions. The caulking material should be applied and pressed into the joint fillingany gaps that might be present.
B.Retro-Coat PRIMER
1.Apply Retro-Coat PRIMER to all areas at a thickness of 6 mil and allow to dry tack free. In areas wherethe concrete surface is in need of slight repair or needs to be leveled, a slurry form of Retro-Coat PRIMER
called Retro-Coat PRIMER-S can be applied with a flat squeegee. Retro-Coat PRIMER-S is self primingand does not need to be primed again.
C. Retro-Coat
1.Mix Retro-Coat, Part A with a low-speed (<750 rpm) jiffy-style mixer for about 30 seconds, or until uniformin color, then mix in Retro-Coat Coating, Part B for another 30-60 seconds.
2.Dump contents onto floor in a ribbon pattern, squeegee, and then back roll at a coverage rate of 160SF/gallon to achieve a film thickness of 10 mils.
3.Apply second coat 10 mil coat to achieve a total thickness of 20 mils. Repeat as necessary to achievespecified thickness.
4.If a flooring material will be placed over Retro-Coat after it is applied, or appearance is not a priority, (1) 20
mil coat can be applied.
2.3 Protection of Finished Work
A.Prohibit foot traffic on floor for 24 hours after laying (at 70ºF). At 50ºF,this time should be extended to 48 hours.
B.Rinse off any chemicals that may come in contact within 7 days of installation with the freshly laid floorimmediately.
2.4 Cleanup
A.Properly dispose of all unused and waste materials.
B.Tools can be washed in warm, soapy water when wet, but after drying, can only be cleaned by grinding or witha paint stripper.
C.Unused resin can be set off with proper amount of hardener and disposed of in regular trash bins.
3 © 2016 Land Science Technologies
Part 3 – Quality Control
3.1 Warranty
A.Installer shall provide a one year warranty against delamination, chemical attack and normal wear and tear.
B.Manufacturer will provide a one year material warranty.
3.2 Quality Control
A.Installer shall use a notched squeegee to apply Retro-Coat to the specified mil thickness and calculations shallbe done to determine if the correct amount of material has been applied. Retro-Coat contains 100% solids atthe time of application; therefore no material shrinkage will occur during the curing process. One gallon willcover 80 square feet.
B.A wet mil film gauge can be used to spot check the Retro-Coat thickness to make certain the minimum 20 milthickness has been applied, though some discretion should be used because high points or low points on the
underlying surface can adversely affect the thickness measurements.
3.3 Floor Care
A.The standard smooth surface of Retro-Coat should be cleaned on a regular basis by damp mopping the floorwith conventional commercial cleaners. It is important to first remove any grease or oils by a suitable cleaner,preferably a citrus based cleaner. Rinse with clear water to help eliminate film buildup and then allow to dry.Never use abrasive powder cleaners like Ajax or Comet as they tend to scratch the floor.
B.Additional steps can also be taken to prolong the look and life of a seamless floor:
1.Protect the floor during transference of heavy equipment
2.Educate the drivers inside the building the importance of avoiding “jack-rabbit” starts and stops, as well askeeping the metal forks lifted
3.Regular cleaning should take place as to not allow the buildup of abrasive material, such as sand or dirt,on the coating
4.Eliminate all metal wheels
5.Change over to light-colored polyurethane wheels
6.Do not slide heavy metal totes, drums or bins across the floor
7.Immediately hose down chemical spills, especially on newly laid floors.
Vapor Intrusion Coating System
for Existing Structures
www.landsciencetech.com
$
$
Key Benefits
Eliminates
Risk
Excellent
Constructability
Highest Chemical
Resistance on
the Market
Competitively
Priced
The Retro-Coat™ Vapor Intrusion Coating System
is a complete product line that consists of chemically
resistant materials to properly protect existing
structures from the threat of vapor intrusion
without the need for additional concrete protec-
tion. Developed by the Research and
Development team of Land Science®, the
Retro-Coat system has been subjected
to rigorous testing procedures to prove
its ability to combat the most aggressive
chemical vapors. The main component of
the Retro-Coat system is the Retro-Coat
coating which is a two part, odorless, no
volatile organic compounds (VOCs), 100%
solids coating.

Available in a variety of colors, Retro-Coat
can be applied on damp as well as dry concrete,
concrete masonry units, tile, brick, and metal. For
enhanced slip resistance, a suitable aggregate can
be added. In addition, other additives or materials
can be utilized to achieve a desired performance
or aesthetic look.
Product Description

Retro-Coat finishes to a high
gloss, easy-to-clean surface that
is impervious to vapor and
moisture intrusion.
Our R&D team developed all of
the Retro-Coat system components
specifically for vapor intrusion protec-
tion in existing structures
Resistant to both TCE and PCE
A wearing surface, meaning no
additional concrete protection is
necessary
No odor and fast cure time reduce
building downtime
Carpet, tile, linoleum or other floor
coverings can be applied directly over
Retro-Coat, if desired
Typical Application
Retro-Coat Advantages
Retro-Coat is a suitable barrier to block contami-
nated vapors from entering existing structures.
Particular uses include coating the horizontal
surfaces of existing structures where contami-
nation under, or adjacent to, a structure can
potentially migrate inside the structure and
create a vapor encroachment condition. This con-
dition is most commonly found when the existing
structure was operated as a dry cleaner, gas station,
manufacturing facility, or located in close proxim-
ity to any structure where carcinogenic chemicals
were utilized.
A typical application consists of a minimum
20 mil thick system and of two 10 mil coats of
Retro-Coat at 160 square foot/gallon per coat
and is recommended along with a 6 mil coat of
Retro-Coat PRIMER. The typical 20 mil application
can withstand forklift traffic, other machinery, and
even act as secondary containment. However, if
Retro-Coat is exposed to harsh conditions over
a longer period of time and/or used for a unique
application, please consult with a Land Science
representative to discuss options and a recom-
mended approach.
Eliminates the need to remove the
existing slab and when combined
with in situ treatment, lowers overall
remediation cost
Can increase the performance of an
existing active sub-slab depressuriza-
tion system
Can aid in the retiring of existing
active systems
Available and installed by Land Science
certified contractors
Former Jazz Club Protected from Vapor Intrusion
Renton, Washington is a bedroom community lo-
cated just outside of downtown Seattle. As a suburb
to downtown Seattle, Renton has seen tremendous
growth over the last two decades as technology
giants like Microsoft, Amazon, and Nintendo
chose the area for their global headquarters. With
commercial properties and home values ever increas-
ing, developers are looking for new ways to restore
brownfield sites quickly and effectively, to allow them
to move forward with future development. In the case
of this former popular jazz club in the historic section
of downtown Renton, indoor air quality was impacted
by volatile organic compounds associated with dry
cleaning solvents that had spread from a nearby dry
cleaning operation.
In May, 2017, Maul Foster Alongi conducted an
indoor air quality assessment at the Property after
installation of Retro-Coat VI System. In order to
obtain samples representative of indoor air conditions
at the Property and to ensure that the same indoor
air conditions existed during the previous indoor air
quality assessment conducted by Maul Foster Alongi
in January 2017.
CASE STUDY: RENTON, WA
The objective of mitigating VI of VOCs into the
building structure for future occupants at the
property has been met by the installation of
the Retro-Coat VI System. The Retro-Coat VI
System provides a long-term solution to the
property indoor air quality issues arising from
the adjoining dry cleaners facility.
Laboratory analytical results for the indoor
air quality assessment after installation of the
Retro-Coat VI System indicated the following:
• The PCE concentration in the dining room
area (JRIA-5 indoor air sample—5.1 μg/m3)
measured below the Department of Ecology
Vapor Intrusion Indoor Air Method B cancer
CUL of 9.6 μg/m3 (DOE, 2016).
• Other VOCs associated with dry-cleaning
solvents, including carbon tetrachloride,
2 butanone, toluene, and xylenes, were also
detected below their respective DOE Vapor
Intrusion Indoor Air Method B cancer CULs.
Challenge:
Results:

Former Industrial Manufacturing Facility Reborn
Challenge:
CASE STUDY: GREENVILLE, SC
A former industrial manufacturing facility in
Greenville, SC was purchased for redevelopment
in 2017. Building improvements were planned to
include a warehouse, offices, and self-storage units
to serve a growing commercial area. Redevelop-
ment plans included converting the industrial
warehouse building into climate controlled self-
storage units, and renovating the office into
an apartment unit and office. Sub-slab soil gas
samples detected various VOCs above the
laboratory method detection limit. Bunnell
Lammons Engineering utilized the Environmen-
tal Protection Agency (EPA) Vapor Intrusion
Screening Level (VISL) calculator to model
potential indoor air concentrations of VOCs
based on the sub-slab soil gas results. Based
on EPA VISL calculations, two VOCs, chlo-
roform and TCE, had estimated indoor air
concentrations above their respective EPA
Industrial/Commercial Risk Based Screening
Level (RSL). The indoor air samples also had
detections of TCE above the EPA Residential RSL.
Results:
Incorporating the vapor mitigation technology
into the anticipated renovations was both
cost and time effective for the site owner. The
combination of Vapor-Vent and Retro-Coat
was determined as a mitigation technique
to reduce the potential risk of harmful
vapor intrusion in the new apartment and
office. Bunnell Lammons Engineering plans
for two rounds of post-mitigation sam-
pling. One was already performed in the
summer of 2019 and one is planned in
the winter between December 2019 and
February 2020 to verify the effectiveness to
the system.
World Class Clients
Environmental consultants, engineers, and real estate professionals trust Land Science to produce results
knowing our expertise and industry knowledge has been proven time and again at the job site. Our world
class clients include leaders in the food, banking, government, and housing industries.
Get Started Today
To receive a custom vapor
intrusion solution, please call
949.481.8118 or email
[e-mail]
One of our Technical Solutions Managers
will review your project details and
provide you with a customized vapor
intrusion solution designed to achieve
your goals.
www.landsciencetech.com
1011 Calle Sombra, San Clemente CA 92673 T: 949.481.8118
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