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Brighton Manor-SY040917 GROUNDWATER INVESTIGATION FOR BRIGHTON MANOR MACARTHUR BOULEVARD AND SAMUEL BOULEVARD COPPELL, TEXAS REPORT NO. S-104-0204 REPORT STREET CUSTOM HOMES COPPELL, TEXAS by GEE CONSULTANTS, INC. GEOTECHNICAL, CONSTRUCTION MATERIALS AND ENVIRONMENTAL CONSULTANTS DALLAS, TEXAS September 17, 2004 T · GEOTECHNICAL ENGINEERING E o ENVIRONMENTALCONSULTING GEE Consultants, Inc. []· CONSTRUCTION MATERIALSTESTING -- 10046 Monroe Drive · Dallas, Texas 75229 · (214) 352-5433 Fax (214) 352-6972 September 17, 2004 Street Custom Homes c/o Mr. Rodney Louviere Dowdey, Anderson & Associates, Inc. 5225 Village Creek Drive, #200 Plano, Texas 75093 RE: Report No. S-104-0204 Groundwater Investigation Brighton Manor MacArthur Boulevard and Samuel Boulevard Coppell, Texas Dear Mr. Louviere: This report transmits the findings of the groundwater investigation performed at the above referenced location. The objective of this investigation was to determine the general stratigraphy of the subsurface formations and groundwater present at the boring location. Results of the field program were combined with a prior test boring and analyzed to provide engineering recommendations for surface groundwater removal as requested. The current study consisted of drilling nine (9) exploratory test borings to explore the subsurface conditions. The location of these test borings are indicated on the Plan of Borings included in the Appendix of this report. Street Custom Homes ~¢ptemher 17. 2004 I. Site Location and Observations The groundwater investigation concentrated in the area of Lots 1 thru 12, Block B, and Lots 9 thru 10 of Block C of Brighton Manor in Coppell, Texas. The regional topographic gradient in the area of Block B, was gently sloping downward toward the northeast toward MacArthur Boulevard and Denton Creek beyond. At the time of our current site investigation, streets were paved with Portland cement concrete. Lots were cleared and brought to grade. The ground surface was covered with exposed orange brown sandy soils, scattered shale fragments and gravel. II. Field Exploration The subsurface exploration consisted of nine (9) test borings drilled on August 24, and September 8, 2004 to depths of two (2.0) to ten (10.0) feet. A prior auger boring was advanced on June 4, 2004, to a depth of four (4.0) feet. The borings were advanced at the approximate location shown on the Plan of Borings included herein. III. Subsurface Soil Description The subsurface materials encountered at the test boring locations consisted of clayey sands, sands, sandy clays, silty clays, shaley clays and clays. Gravel was noted at various depths. One (1.0) to four (4.0) feet of fill material was encountered at test boring locations B-2, B-3, B-4, B-6 and B-9. This fill material consisted of very stiff to hard sandy clays and silty clays. Gray shale was encountered at various depths at several test boring locations. A summary of shale depth measurements is as follows: DEPTHS TO SHALE AT TEST BORING LOCATIONS Boring Locations Depth of Gray Shale Below Presently Existing Grade (Feet) B-IA 4.0 B-l, B-6, B-7 6.0 B-3, B-5 9.0 B-4 7.0 B-8 3.5 B-9 2.0 GEE Consultants, Inc. Report No. S-104-0204 -- Page 2 Street Custom Homes Sentember 17. 2004 Detailed descriptions of the various strata encountered are presented on the individual Logs of Boring in the Appendix of this report. IV. Surface and Subsurface Water Conditions At the time of field exploration, groundwater or seepage was encountered at various depths at several of the test boring locations. A summary of water depth measurements is as follows: SUMMARY OF WATER LEVEL MEASUREMENTS Boring Depth to Water Below Depth to Water Below Location Presently Existing Presently Existing Grade Grade (Feet) (Feet) Upon Completion of During Drilling Drilling B-lA** 1.0 i.0 B-1 7.0* NE B-4 4.0 3.5 B-5 2.0 4.0 B-6 3.0 3.5 B-8 3.0 2.8 B-9 NE NE ** - Drilled During Previous Investigation On June 4, 2004 * - Seepage NE - None Encountered Wet spots or standing water were visually observed five (5) days after an approximately one-half (0.5) inch rain. The standing water and wet spots were observed along the surface of the drainage swales between Lots 7 and 8, Block B, Lots 8 and 9, Block B, Lots 9 and 10, Block B, Lots 9 and 10, Block C and at the surface in the northwest comer of the Lot 1, Block B building pad. The subsurface water regime is subject to change with variations in climatic conditions. If there is a noticeable change from the conditions reported herein, GEE Consultants, Inc. should immediately be notified to review the effect it may have on the enclosed analysis and recommendations. It is not possible to accurately predict the magnitude of subsurface water fluctuations that might occur based upon short- term observations. GEE Consultants, Inc. Report No. S-104-0204 Page 3 Street Custom Homes Sentember 17. 2004 V. Limitations The professional engineering services performed, findings obtained, and recommendations prepared were accomplished in accordance with currently accepted geotechnical engineering principles and practices. The possibility always exists that the subsurface conditions at the site may vary from those encountered at the boreholes. If there are any unusual conditions differing significantly from those described herein, GEE Consultants, Inc. should immediately be notified to determine the effects on the performance of the designed surface groundwater removal system. The recommendations given in this report were prepared exclusively for the use of Street Custom Homes and/or their consultants. The information supplied herein is applicable only for the design of the surface groundwater removal system. This information should not be used for any other purpose. GEE Consultants, Inc. is not responsible for the conclusions, opinions, or recommendations made by others based on this information. Also, this firm is not responsible for damages caused by the workmanship of the contractors. The quality of all phases of the construction of the proposed surface groundwater removal system should be checked by qualified personnel to insure that the work is done in the field in accordance with the accepted plans and specifications. VI. Analysis and Recommendations A. Groundwater Observations Analysis It is our understanding a well located in the area of Lot 1, Block B was capped during the course of subdivision construction. Since the well has been capped and was not under pressure (Artesian type well) it is our opinion this is not the source of the present shallow groundwater. It is our opinion the shallow groundwater and wet spots noted on site are perched water. The perched water is currently present due to well above average levels of rainfall since the first of the year (eleven (11) inches above normal year, to-date). The perched water is the result of the rainwater ponding on top of underlying relatively impermeable clays and shales. Shale and shaley clay were noted at shallow depths at numerous locations in the original and current geotechnical investigations. Soils encountered at the current boring locations from the surface to the top of the shale and shaley clay consisted of fill with sand and gravel, clayey sand, sand, sandy clay, and clays, silty clays with embedded gravel and sand layers. The near surface soils are highly permeable. It is our opinion that shallow water is being trapped (perched) on top of the shale and shaley clay formation. The groundwater is then traveling horizontally through the permeable soils with embedded gravel, sand layers to the nearest point of relief. GEE Consultants, Inc. Report No. S-104-0204 -- Page 4 Street Custom Homes Sentember 17. 2004 B. Surface Groundwater Removal System As discussed previously, shallow ground water was encountered at test boring locations B-lA (swale between Lots 8 and 9, Block B), B-4 (between Lots 4 and 10, Block B), B-5 (swale between Lots 3 and 4, Block B), B-6 (swale between Lots 4 and 5, Block B) and B-8 (swale between Lots 2 and 3, Block B). In addition wet spots/standing water were observed along the surface of the swales between Lots 7 thru 10, Block B, Lots 9 and 10, Block C and in the northwest portion of Lot 1, Block B. We recommend improving the drainage/groundwater conditions in the areas of test boring location B-5 (groundwater shallower than two (2.0) feet) and the above mentioned wet spots. This will reduce potential for wet/quagmire conditions during shallow foundation construction. Drainage improvements should include installing drain lines. The drain lines should be located between Lots 3 and 4, Block B, Lots 7 and 8, Block B, Lots 8 and 9, Block B, Lots 9 and 10, Block B, Lots 9 and 10, Block C and along the backside of the pad at Lot 1, Block B (see Plan of Borings). The upper three (3.0) feet of soil along the proposed line location should be removed. A four (4) to six (6) inch diameter slotted PVC or perforated pipe should be placed along the bottom of the excavation. The removed soil should then be replaced with three-fourths (3/4) inch to one (1) inch crushed stone to a depth of twelve (12) inches below final grade. The crushed stone should surround the four (4) to six (6) inch pipe. The crushed stone will do a better job of supporting surface loads. The pipe should consist of a four (4) to six (6) inch diameter slotted PVC or perforated pipe surrounded by four (4) to six (6) inches of three-fourths (3/4) inch to one (1) inch crushed stone cover. The crushed stone should be placed over, under and around the pipe. A filter fabric material should be wrapped around the crushed stone and pipe. All fabric laps should be a minimum of six (6) inches. The closure (fabric overlap) should be stitched at minimum intervals of five (5.0) feet. The installation of at least two (2) clean-outs is recommended for each lot to keep the system free of debris and functioning properly. The pipe should be sloped to drain downward at a minimum fall of one (1) inch per ten (10.0) feet. In lleu of the solid pipe gravity outfall system, consideration could be given to utilizing a sump pump collection system. The groundwater collected by the drain pipe should be allowed to accumulate in a sump pump and pumped through the existing curb onto the concrete pavement. __~ _ .... Both the sdlid pip~e gravi/~ ~/i~f~ll system and/or the sump pump collection system located in street easements will need design input from the Civil Engineer and approval from the City of Coppell. GEE Consultants, Inc. Report No. S-104-0204 -- Page 5 Street Custom Homes ~¢ptember 17. 2004 The remaining upper twelve (12) inches of near surface backfill should consist of a clay cap. Clay cap material should have a minimum plasticity index of twenty-five (25) and be compacted to a minimum of ninety-five (95) percent of the maximum density as determined by ASTM D 698. The potential exists for groundwater to be present in lots not discussed in this report if significant rainfall continues. If groundwater is present in grade beam excavations, structural loads may need to be supported using pier foundation systems. In cases where groundwater is encountered in grade beam excavations, foundation construction may need to be delayed until french drain(s) are installed or other measures taken. C. Additional Recommendations and Discussion With the exception of test boring locations B-2, B-3 and B-4, all of the test borings were advanced in swales located between lots. The swales were typically about eight (8) to thirty (30) inches lower than adjacent finish pad elevations. Assuming shallow foundations will utilize grade beams founded approximately eighteen (18) inches below grade, groundwater deeper than thirty (30) inches below finish pad elevation will not effect the allowable design bearing capacity. Taking into account the elevation of swales compared to current finish pad elevations, groundwater deeper than two (2.0) feet at the current boring locations should not effect the design of the foundations. To reduce potential for wet spots, we recommend ground cover or grass be planted in current areas of wet spots and standing water. Vegetation will promote transpiration and provide a better living surface for residents. From up slope adjacent properties, water due to sprinklers, pools, etc. should be prevented from draining into the area. This will reduce the potential for wet spots and standing water on the subject site. If persistent rainy weather continues, drain construction should be completed at least three (3) months prior to any foundation construction. This time period may be able to be reduced after extended dry, hot weather periods. Drain installation in advance will reduce the potential for subgrade shrinkage and groundwater beneath the foundation. To ensure that the recommendations contained in this report are properly implemented, we recommend periodic inspections be conducted during drain construction. Additionally, we recommend confirmation of all materials to be used prior to construction. To reduce potential for foundation settlement due to fluctuation of groundwater levels as a result of seasonal variations in climatic conditions, GEE Consultants, Inc. Report No. S-104-0204 -- Page 6 Street Custom Homes Sentember 17. 2004 we recommend utilization of pier foundation system. Pier casing may be necessary at some locations during construction. It should be understood that groundwater levels and moisture are highly variable and tricky. No guarantee or warranty is implied that the recommendations outlined above will correct conditions observed, or that detrimental conditions may not occur in the future. Our recommendations should be reviewed by your Civil and Structural Engineer as well as your Landscape Architect. We appreciate the opportunity to be of service to you on this project. We will be happy to discuss any questions you may have concerning this report. We look forward to serving you in the future. Very truly yours, GEE Consultants, Inc. Division Manager Geotechnical Engineering Division AJA:RWG/js Attachments President RICHARD WAYNE GEE % -~. 67238 ~ *. ~ ' GEE Consultants, Inc. Report No. S-104-0204 -- Page 7 ~ j Number Location Page I of I Log of Boring [ B-lA I SEE PLAN OF BORINGS S-104-0172 Project GROUNDWATER INVESTIGATION, BRIGHTON MANOR, MACARTHUR BLVD., COPPELL~ TEXAS IT Type ~ CONTINUOUS AUGER o ~.~.~ Surface Elevation ~ ~ ~ ~ ~ .~ ~ .~ ~ o~ N/A ~ ~ ~ ~ ~ ~ '~ ~ ' ~o= ST~TUM DESC~PTION '~ ~ ~. ~ ~- : o~ TAN CLAYEY SAND (MOIST) -with gravel -hole caved in ~om 1.5' to 4.0' 4.0 END OF BOR~G -veu hard (auger re~sal) ~ 4.0' 4.0' 6/4/2004 WATER ENCOUNTERED ~ 1.0'; GEE Consultants, Inc. Number Location Page I of 1 Log of Boring I B-1 [ SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER 1NV., BRIGHTON MANOR, MACARTHUR BLVD. & SAMUEL BLVD., COPPELL~ TEXAS ~ ~/~ Type ~ ~ . INTERMITTENT SAMPLING ~  4.5+ O~NGE BRO~ AND BRO~ CLAYEY SAND -with sand and gravel  4.5 2.0 TAN AND GRAY SHALEY CLAY 4.5+ -with occasional calcium deposits ~ 3.0' 5 4.5+ 6.0 GRAY SHALE 10 10.0 END OF BOR~G Completion Depth Date [ Water Obse~ations 10.0' 8/24/2004[ SEEPAGE ~ 7.0' GEE Consultants, Inc. Number Location Page I of 1 Log of Boring I B-2 [ SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER INV., BRIGHTON MANOR, MACARTHUR BLVD. & SAMUEL BLVD. COPPELL, TEXAS ~ ~E~ Type ~-L~'~ ~. INTERMITTENT SAMPLING ~ v ~ .a Surface Elevation ~ ~-o ST~TUMDESC~PTION s~ ._ ~ ~= l ~ ~ 4.5+ O~NGE BRO~ AND BRO~ SANDY CLAY ,~,'~' (Fill) , ~, 4.5+ -with sand layers, roots ~d gravel ' ' ' 4.5+ -wi~ occasional concrete fragmen~ ~ 2.0'  -- 3.0 TAN SAND 5 4.5 5.0 TAN AND G~Y S~LEY CLAY -with fine sand se~s 4.5+ 4.5+ -with calcium deposits ~ 9.0' 10 10.0 END OF BOR~G Completion ~p~ Date I Water Obsemations 10.0' 8/24/20241 NO WATER ENCOUNTERED GEE Consultants, Inc. Number Location Page 1 of 1 Log of BoringIB-3 [ SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER INV., BRIGHTON MANOR, MACARTHUR BLVD. & SAMUEL BLVD., COPPELL~ TEXAS .~ Type ~. INTERMITTENT SAMPLING ~ ~ o o~ N/A ~ ~ ~ ~ ~ ~-~ ST~TUM DESC~PTION "= a~ ~ ~ ',',', 4.5+ BRO~ SANDY CLAY (Fill) ,,,''"'~'~"'~"~''", 4.5-- 3.5 3.5 -withorangesandlayers~l.0'  4.00~NGE BRO~ SAND 5 4.5+ 5.0 TAN AND G~Y SHALEY CLAY -with calcium deposits 3.5 4.5 9.0 G~Y SHALE 10 10.0 END OF BOR~G Completion Dep~ Date Water Obse~ations 10.0' 8/24/2004 NO WATER ENCOUNTERED GEE Consultants, Inc. Number Location Page I of l Log of Boring [B-4 I SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER INV.~ BRIGHTON MANOR~ MACARTHUR BLVD. & SAMUEL BLVD., COPPELL~ TEXAS ~ I~r~~~'~ Type~.~ ,. INTERMITTENT SAMPLING ~ ~- o -Surface Elevation . .~~ :.~~ ~ ~ m ~ravel ~ ~ 4.5+ 1.0 BRO~CLAY -Mt~ ~a ments 4.0 2.0 BRO~ AND GRAY S~LEY CLAY ~ 3.0~ ~ ~ 4.00~NGE BRO~ CLAYEY SAND 5 -with gravel and sand layers  50/5" 7.0 G~Y SHALE 10.0 END OF BORING Completion Dep~ Date Water Obse~ations 10.0' 8/24/2004 WATER ENCOUNTERED ~ 4.0'; ~ 3.5' UPON COMP. GEE Consultants, Inc Nmnber Location Page I of 1 Log of Boring I 8-5 I SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER INV., BRIGHTON MANOR, MACARTHUR BLVD. & SAMUEL BLVD., COPPELL~ TEXAS ~ Type :- ~. INTERMITTENT SAMPLING ~ '~ o~ N/A ~ ~ : o ~ ST~TUM DESC~PTION ~ravel 10 1.00~NGE BRO~ SAND ~ -wi~ iron deposits and gravel 20 10 ,/././././.~ 5.5 G~Y AND TAN SHALEY CLAY ~ -with sand and gravel ~ 3.75 9.0 G~Y SHALE I 0 100/7' 10.0 END OF BOR~G 10.0' 8/24/2004] WATER ENCOUNTERED ~ 2.0'; ~ 4.0' UPON COMP. GEE Consultants, Inc Number Location Page I of 1 Log of Boring I B-6 [ SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER INV, BRIGHTON MANOR~ MACARTItUR BLVD. & SAMUEL BLVD., COPPELL~ TEXAS ~ Type '~ INTERMITTENT SAMPLING ~ ~ .~ ~ Surface Elevation ~..~ '~- ~ ~ ~ ~ ST~TUM DESC~PTION * ~ :l:l',~:l:l 3.0 BRO~ S1L~ CLAY (Fill) ~11111~ ~ ~ ~ -wi~ iron and occasional roots ~ -- 1.o 'O~NGE BRO~ SAND -with gravel ;~< 4.5 BRO~ AND G~Y SHALEY CLAY 5-- ~ 4.0 -with occasional calcium deposits 6.0 G~Y SHALE 10 10.0 END OF BOR~G Completion Depth Date I Water Obse~ations 10.0' 8/24/2004] WATER ENCOUNTERED ~ 3.0'; ~ 3.5' UPON COMP. GEE Consultants, Inc. Number Location Page [ of 1 Log of Boring [B-7 I SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER INV., BRIGHTON MANOR, MACARTHUR BLVD. & SAMUEL BLVD., COPPELL, TEXAS , ~ Type ~ INTERMITTENT SAMPLING ~ .~ ~ Surface Elevation ~ 6 ' -~ ~ ~ ~~~ ' ~ ~ STRATUM DESCRIPTION ~ 4.0 BROWN CLAY -with iron and sand seams ~ 4.5+ 1.o ORANGE AND GRAY SHALEY CLAY 4.5+  4.5+ 3.0 DARK GRAY SHALEY CLAY -with calcium deposits 6.0 GRAY SHALE 10 10.0' 8/24/2004 NO WATER ENCOUNTERED GEE Consultants, lnc Nmnber Location Page I of 1 Log of Boring I g-8 I SEE PLAN OF BORINGS S-104-0204 Project GROUNDWATER INV. BRIGHTON MANOR, MACARTHUR BLVD. & SAMUEL BLVD., COPPELL~ TEXAS ~ Type ~' INTERMITTENT SAMPLING ~ = ~ ~ ST~TUMDESC~PTION ~ = r~ ~z O~NGE SAND ~ravel 1.00~NGE SAND -with thio layer of river gravel ~ 3.3' ~-with shale encountered ~ 3.5' ~ 3.5 END OF BOR~G Completion3.5,Dep~ 9/8/2004 ~ WATER ENCOUNTERED ~ 3.0'~ 2.8 UPON COMP. GEE Consultants, Inc Number Location Page I of 1 Log of Boring [B-9 I SEE PLAN OF BORING S-104-0204 Project GROUNDWATER INV, BRIGHTON MANOR~ MACARTHUR BLVD. & SAMUEL BLVD., COPPELL~ TEXAS ~ Type ~. INTERMITTENT SAMPLING o v .o .,a Surface Elevation ' *~ ~ ~*~ ST~TUMDESC~PTION ~ ~ ~~ ~ ~ ~*~ ~ ~ ~ ~ ~ -with dark gray clay, pea gravel md dark gray shale ~ 1.0 X fragments / . YELLOWISH BRO~ AND, G~Y SHALEY CLAY/ 2.0 ~-wi~ shale encountered ~ 2.0 END OF BORING 2.0' 9/8/2004 NO WATER ENCOUNTERED GEE Consultants, Inc. - Symbols and Terms Used on Boring Logs SOIL OR ROCK TYPES .'..c~..? ~"jI" "__'L ::::::::1 Fill Sandy Silty Clayey Sandstone Shale Limestone Shelby Rock Split Auger No Asphalt Tube Core Spoon Recovery CONSISTENCY OF COHESIVE SOILS DESCRIPTIVE TERM Very Soft Soft Firm Stiff Very Stiff Hard UNCONFINED COMPRESSIVE STRENGTH (TON/SQ. FOOT) Less than 0.25 0.25-0.50 0.50-1.00 1.00-2.00 2.004.00 More than 4.00 RELATIVE DENSITY OF COHESIONLESS SOILS Std. Penetration Resistance Descriptive Term Relative Density Blows/Foot 0-10 Loose 0 to 40% 10-30 Medium Dense 40 to 70% 30-50 Dense 70 to 90% OVER 50 Very Dense 90 to 100% SOIL STRUCTURE Calcareous Slickensided Laminated Fissured Interbedded Containing deposits of calcium carbonate: generally nodular Having inclined planes of weakness that are slick and glossy in appearance Composed of thin layers of varying color and texture Containing shrinkage cracks frequently filled with fine sand or silt: usually more or less vertical Composed of alternate layers of different soil types PHYSICAL PROPERTIES OF ROCK Very Soft or Plastic Soft _ Moderately Hard Hard Very Hard Poorly Cemented or Friable -- Cemented HARDNESS AND DEGREE OF CEMENTATION Can be remolded in hand: corresponds in consistency up to very stiff in soils Can be scratched with fingernail Can be scratched easily with knife: cannot be scratched with fingernail Difficult to scratch with knife Cannot be scratched with knife Easily crumbled Bound together by chemically precipitated material occurring in the interstices between allogenic particles of rock quartz, calcite, dolomite, siderite and iron oxide are common cementing materials PHYSICAL PROPERTIES OF ROCK Unweathered Slightly Weathered Weathered Extremely Weathered GEE Consultants, Inc. DEGREE OF WEATHERING Rock in its natural state before being exposed to atmospheric agents Noted predominantly by color change with no disintegrated zones Complete color change with zones of slightly decomposed rock Complete color change with consistency, texture, and general appearance approaching soil SOIL CLASSIFICATION SYSTEM SYM- TYPICAL NAMES MAJOR DIVISIONS BOLS GW Well graded gravels, gravel sand mixtures, C~ little or no fines. GP, AVELS GRAVELS (Little or (More than no fines) Poorly graded gravels or gravel sand 50% of GP mixtures, little or no fines. coarse fraction is LARGER than the No. 4 GRAVELS GM silty gravels - sand - silt mixtures. U.S. Sieve WITH FINES COARSE size) (Appreciable GRAINED amt. of SOILS fines) SC Clayey gravels, gravel sand - clay mixtures. (More than 50% of material is Well graded sands, gravelly sands, little or LARGER than SW no fines. No. 200 U.S. CLEAN SANDS Sieve size) SAlaDS (Little or (More than no fines) 50% of SP Poorly graded sands or gravelly sands, little or no fines. coarse fraction is SMALLER than the No. 4 SANDS SM Silty sands, sand silt mixtures. U.S. Sieve WITH FINES size) (Appreciable amt. of fines) SC Clayey sands, sand-clay mixtures. Inorganic silts and very fine sands, rock ML flour, silty or clayey fine sands or clayey silts with slight plasticity. SILTS P. ND CLAYS Inorganic clay of low to medihum plasticity, (Liquid limit CL gravelly clays, sandy clays, silty clays, LESS than 50) lean clays. FINE GRAINED SOILS OL Organic silts and oganic silty clays of iow plasticity. (More than 50% of material is SMALLER than MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts. NO. 200 U.S. Sieve size) SILTS AND CLAYS (Liquid limit CH Inorganic clays of high plasticity, fat clays. GREATER than 50) OH organic clays of medi~ to high plasticity, organic silts. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. BOUNDARY CLASSIFICATIONS: Soils possessing characteristics of two groups are designated by combinations of group symbols. _ GEE Consultants, Inc.