Att_11_P8419R0006_Percolation_Test_Report.pdf

286 W. Cromwell Avenue

Fresno, CA 93711-6162

Tel: (559) 449-2700

Fax: (559) 449-2715 www.ppeng.com

G:\Siegel_Strain-1961\196117006-Pinnacles NP East Entrance Station\_DOCS\Reports\Draft Percolation Testing Technical Memo -edited 20180614.docx

Engineering Surveying Planning Environmental GIS Construction Services Hydrogeology Consulting

Fresno Bakersfield Visalia Clovis Modesto Los Banos Chico Merced

Memorandum To: Sarah Raube, PWRO – National Park Service

From: Rod McNeely, Shay Overton & Soo Ho Park - Provost & Pritchard Consulting Group

Subject: Technical Memo: Replace the East Entrance Station – Percolation Test Pit Results

Date: June 14, 2018

Shay Overton, C.H.G Rod McNeely, P.E.

Senior Geologist Principal Engineer

Introduction

Provost & Prichard Consulting Group (P&P) was contracted under Task Order P17PD02012 to provide the Civil Scope of the Task Order to replace the East Entrance Station at Pinnacles National Park. As described in the Scope of Work document, P&P was contracted to provide a document summarizing the percolation test locations, findings of the testing, their effect on the wastewater design alternatives, including potential sizes, areas, and depth of systems.

The percolation testing was conducted on January 16-17, 2018. There were three parties represented during the percolation testing and field review. P&P provided the staff to conduct the soil profile log and the percolation testing. Pinnacles National Park Staff provided the backhoe, backhoe operator, and the wildlife biologist. Lastly, a San Benito County Environmental Health Inspector was present to observe the soil classification on the first day of the field investigation.

Test locations The test locations for the potential East Entrance Stations were narrowed down to three general areas and a total of four test pit locations within those areas. The three areas were identified as South Site Primary, South Site Alternate, and North Site locations. Within these areas, P&P conducted one percolation test pit near each of the primary and alternate South Site locations, and two near the North Site location. The aerial exhibits of the surveyed test pit locations, Exhibit A, is attached to the end of this memorandum.

06/14/2018 06/14/2018

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These test pits were sited based on two criteria. First, they were sited within reasonable proximity to the potential entrance station locations. Secondly, the horizontal offset requirements as identified in the California Onsite Waste Water Treatment Systems (OWTS) Policy (2012) and the draft San Benito County OWTS Local Agency Management Plan (LAMP) (2017) were followed. Based on these policy documents the percolation test pits were sited with a minimum 100 feet horizontal setback from the bank of Sandy Creek and at least 150 feet setback from the public well near the South Sites. These offset requirements are also graphically represented in Exhibit A.

NRCS Soil Data

The first step in identifying potential leach field areas, National Resources Conservation Service reports for the Area of Interest were reviewed and are included in Exhibit B.

These reports show potential leach fields are in areas of soil classified as Elder Gravelly Sandy Loam or Toags Gravelly Course Sand. The USDA Official Soil Series Descriptions define the Elder Series as “very deep and deep, well drained soils that formed in alluvial material derived from mixed rock sources. Elder soils are on alluvial fans and in flood plains and have slopes of 0 to 15 percent.” The Toags Series are defined as “very deep, somewhat excessively drained soils that formed in alluvium derived from igneous rocks. The Toags soils are on stream terraces. Slopes range from 0 to 5 percent.”

The percolation test pits are situated in or close to alluvial fans and the soil profile logs report very similar materials as described in the following section. There are no hardpans mentioned in these soil series and the field investigation confirmed these reports. Therefore, these soils are considered well drained soils with negligible to low runoff from rainfall. These are generally desirable characteristics for leach fields and our field investigation results, discussed in following sections, confirmed the suitability of leach fields in the tested locations.

Field Investigation

Test Pits In accordance with the work plan, the Pinnacles Park staff provided the backhoe with a 24-inch bucket to dig the test pits. A P&P geologist supervised the excavation of the test pits, classified soils, and conducted percolation testing. Within each test pit, two percolation tests were done at approximately 2 and 4 feet. The logs of the test pits are attached in Exhibit C.

Subsurface Soil Conditions The soils in Test Pit #1 consists of gravelly silty sand with varying amounts of clay down to 12 feet. Between 12 to 13 feet, the sand became more silty and clayey causing that layer to be slightly cemented. At 13 to 13.5 feet, the sand had traces of silt and its grain size was fine to very coarse. Additional details can be found in the Test Pit #1 log in Exhibit C.

Test Pit #2 consists of a silty clayey sand without much structure up to a depth of 4 feet.

Between 4 to 6 ½ feet, the logs report a sandy clay layer with clods and voids. At 6 ½ to 10 feet, sand with very slight cementation had grain sizes ranging from fine to gravel and this layer included some oxidation mottle. Lastly, between 10 to 13 feet, the sand with silt and clay was blue/grey in color and more coarse grained. Groundwater was noted seeping into the test pit at approximately 13 feet. Additional details can be found in the Test Pit #2 log in Exhibit C.

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Test Pit #3 consists of sand with a trace of silt which was very loose with no signs of oxidation up to 7 feet. Between 7 to 8 feet, there was slightly cemented sand with silt. At 8 to 13 feet, the sand with silt was rocky with up to 40% of the soil consisting with rocks up to 6-inches in diameter. Additional details can be found in the Test Pit #3 log in Exhibit C.

Test Pit #4 consists of a sand with traces of silt ranging from fine to very course with some gravel to a depth of 3 feet. Between 3 to 8 feet, the sand with silt begins to include rocks and by 7 feet, rocks ups to 6-inches in diameter begin to account for 30-40% of the soil. At 12-13 feet, the sand with trace silt is very course to medium with the same 30-40% rock composition.

Additional details can be found in the Test Pit #3 log in Exhibit C.

Groundwater Conditions No groundwater, saturated soils or seepage were encountered except in Test Pit #2. The soils in Test Pits #1, 3, & 4 were reviewed for evidence of seasonally high ground water (evidence such as characteristic vegetation, mottled soils, blackened zones or pockets of residual saturation), but to the depth of exploration, there appears to be no evidence of seasonal high groundwater.

In Test Pit #2, ground water was at 13 feet. Although this does not eliminate the feasibility of this test pit location as a potential leach field site, if this location is used, the design shall ensure a minimum separation of 5’ vertical feet from seasonal high groundwater to bottom of trench.

Percolation Tests Percolation tests were performed in accordance with the Manual of Septic Tank Practice prepared by the U.S. Department of Health, Education, and Welfare.

Results of the percolation tests are presented below. Locations of the percolation tests are shown in Exhibit A.

Test Pit # Clear Water Absorption Rate (min/in)

Test Pit 1 55

Test Pit 2 125

Test Pit 3 5

Test Pit 4 30

Test Pit 3 & 4 Average 20

For the potential entrance station locations on the South Sites, the recommended leach field would be sited at or near Test Pit #1. The soil log from Test Pit #2 reports clayey soils and relatively shallow groundwater (13’) indicates that Test Pit #2 would be a less ideal location to construct a leach field. Also, there were some underground telephone lines in close proximity to Test Pit #2 as surveyed and shown in Exhibit A.

For the potential entrance station location on the North Site, Test Pits #3 & #4 both reported suitable percolation rates. Since the two test pits were close in proximity to one another, the percolation rates from these two pits were conservatively averaged to 20 min/in as show in the table above.

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Therefore, when calculating the application rate for design, a percolation rate of 55 min/in and 20 min/in should be used for the South and North site, respectively.

Demand Analysis

To be able to size an appropriate on-site wastewater treatment system, we conducted conservative calculations based on our understanding and staffing of the East Entrance Station facilities. We understand that during the peak operational season the entrance station could have 2-3 employees on shift and potentially augmented by a law enforcement officer as necessary. Therefore, during a peak season 12-hour work day, we assumed that there could be 4 employees per shift and two shifts per day. Lastly, we assumed that each employee on average will use the restroom facility four times per shift.

To summarize our estimate, it is our assumption that 8 different employees will use the restroom facilities 4 times each, resulting in 32 uses. At 1.6 gallons per toilet flush and 0.25 gallons per utility sink use, the total wastewater generation is 59 gallons per day (gpd). Using a conservative factor of safety of 2, we calculate the wastewater demand as 118 gallons per day which is rounded to120 gpd for simplicity.

On-site Wastewater Treatment System Schematic Design

Septic Tank Capacity

Based on the Demand Analysis estimated above, the Uniform Plumbing Code indicates that, for a Waste/sewage flow up to 1500 gallons per day the minimum septic tanks size is calculated as:

Minimum Septic tank size = Flow x 1.5 Minimum Septic tank size = 120 gallons per day x 1.5 = 180 gallons.

Although this is the minimum septic tank size for the design of the leach field, the minimum septic tank size as required by the San Benito County LAMP is 1,000 gallons, this will allow for more than adequate retention time of the effluent before it is drained to the leach field.

Application Rate

The Application Rate is calculated from the percolation test by:

A.R. =5/ percolation Rate

For Leach Field Area South

A.R. = 5/ = 0.68 gallons per day per square foot

For Leach Field Area North

A.R. = 5/ = 1.12 gallons per day per square foot

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Loading Factors

The Loading Factor is calculated from the Application Rate by:

L.F. = 100/A.R.

Using the computed Application Rate, the Loading Factors would be:

L.F. = 147 square feet per 100 gallons of septic tank size

L.F. = 89 square feet per 100 gallons of septic tank size

Total Absorption Area Requirements

The total absorption area requirements are typically calculated from the Loading Factor and the size of the septic tank. Given that the minimum size septic tank volume defined by the County grossly exceeds the expected daily waste water generation, we will use the conservative daily flow of 180 gpd for the purpose of sizing the leach field. The required absorption area (leach field trench sidewall and bottom area) is calculated by multiplying the Loading Factor times each hundred gallons of daily wastewater generation volume.

Absorption Area Requirements = 147 x 1.8 Absorption Area Requirements = 265 square feet

For Leach Field Area North

Absorption Area Requirements = 89 x 1.8 Absorption Area Requirements = 160 square feet

Leach Field Size

The recommended leach field trench is two feet wide and 7 feet deep. A leach pipe invert at 3 feet should be used where ground slope allows. In areas of sloping ground, the invert may need to be placed a few feet deeper. In this instance, the trench depth below the pipe invert shall remain at 4 feet. The useable sidewall in the trench is the area from one foot below the bottom of the pipe invert in the trench to the bottom of the trench times two sidewalls. For this recommended layout, the allowable disposal area is 8 square feet per lineal foot of trench. This equates to total leach field trench lengths as follows:

Total Leach Field Trench Length = 265 / 8

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Total Leach Field Trench Length = 34 lineal feet

Total Leach Field Trench Length = 160 / 8 Total Leach Field Trench Length = 20 lineal feet

Leach Line Spacing

The leach line trenches should be spaced a minimum of 8 feet apart. As indicated by the Uniform Plumbing Code, for disposal fields placed on sloping ground, the minimum horizontal distance between any part of the leaching system and ground surface shall be 15 feet.

Leach Field Configuration

For Leach Field Area South

The leach lines should be constructed in two halves, each half consisting of 17 feet long. The two halves should have a distribution box placed between them to allow periodic switching of the sewage effluent loading.

For Leach Field Area North

The leach lines should be constructed in two halves, each half consisting 10 feet long. The two halves should have a distribution box placed between them to allow periodic switching of the sewage effluent loading.

Leach Field Location and 100% Replacement Area As required by the California OWTS Regulation, an area equal to 100% of the size of the leach field would be set aside for a replacement leach field. Due to the sensitive nature of construction in Pinnacles National Park and the relatively small minimum design size of the leach field, it is recommended that the leach field is doubled in size to account for this regulation requirement.

Therefore, the lengths for each of the leach line halves should be doubled to 34 feet and 20 feet, respectively, for the South and North sites. An O&M plan will be developed to allow for alternating use of both leach fields and increase the overall lifespan of the leach field.

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EXHIBIT A – PERCOLATION TEST PIT LOCATIONS

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EXHIBIT B – NRCS SOILS REPORTS

Depth to Any Soil Restrictive Layer—Pinnacles National Monument, California (Pinnacles)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/26/2018

666440 666520 666600 666680 666760 666840 666920 667000 667080 667160 667240

666440 666520 666600 666680 666760 666840 666920 667000 667080 667160 667240

36° 30' 51'' N

1°

' 2 9'

' W 36° 30' 51'' N

1°

' 5

6' ' W

36° 30' 34'' N

1°

' 2

9' ' W

36° 30' 34'' N

1°

' 5

6' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 150 300 600 900

Feet 0 50 100 200 300

Meters Map Scale: 1:3,780 if printed on A landscape (11" x 8.5") sheet.

Soil Map may not be valid at this scale.

MAP LEGEND MAP INFORMATION

Area of Interest (AOI) Area of Interest (AOI)

Soils Soil Rating Polygons

0 - 25

25 - 50

50 - 100

100 - 150

150 - 200

> 200

Not rated or not available

Soil Rating Lines 0 - 25

25 - 50

50 - 100

100 - 150

150 - 200

> 200

Not rated or not available

Soil Rating Points 0 - 25

25 - 50

50 - 100

100 - 150

150 - 200

> 200

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 31, 2009—Mar 1, 2017

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Depth to Any Soil Restrictive Layer—Pinnacles National Monument, California (Pinnacles)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/26/2018

Depth to Any Soil Restrictive Layer

Map unit symbol Map unit name Rating (centimeters) Acres in AOI Percent of AOI

117 Elder gravelly sandy loam, 0 to 1 percent slopes

>200 26.4 51.7%

119 Still clay, 0 to 2 percent slopes

>200 3.3 6.4%

134 Toags gravelly coarse sand, 2 to 9 percent slopes

>200 3.8 7.4%

142 Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

92 17.6 34.5%

Totals for Area of Interest 51.1 100.0%

Description

A "restrictive layer" is a nearly continuous layer that has one or more physical, chemical, or thermal properties that significantly impede the movement of water and air through the soil or that restrict roots or otherwise provide an unfavorable root environment. Examples are bedrock, cemented layers, dense layers, and frozen layers.

This theme presents the depth to any type of restrictive layer that is described for each map unit. If more than one type of restrictive layer is described for an individual soil type, the depth to the shallowest one is presented. If no restrictive layer is described in a map unit, it is represented by the "> 200" depth class.

This attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used.

Rating Options

Units of Measure: centimeters

Aggregation Method: Dominant Component

Component Percent Cutoff: None Specified

Tie-break Rule: Lower

Interpret Nulls as Zero: No

Depth to Any Soil Restrictive Layer—Pinnacles National Monument, California Pinnacles

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Hydrologic Soil Group—Pinnacles National Monument, California

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/26/2018

666440 666520 666600 666680 666760 666840 666920 667000 667080 667160 667240

666440 666520 666600 666680 666760 666840 666920 667000 667080 667160 667240

36° 30' 51'' N

1°

' 2 9'

' W 36° 30' 51'' N

1°

' 5

6' ' W

36° 30' 34'' N

1°

' 2

9' ' W

36° 30' 34'' N

1°

' 5

6' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 150 300 600 900

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

A

A/D

B

B/D

C

C/D

D

Not rated or not available

Soil Rating Lines A

A/D

B

B/D

C

C/D

D

Not rated or not available

Soil Rating Points A

A/D

B

B/D

C

C/D

D

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 31, 2009—Mar 1, 2017

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Hydrologic Soil Group—Pinnacles National Monument, California (Pinnacles)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Hydrologic Soil Group

Map unit symbol Map unit name Rating Acres in AOI Percent of AOI

117 Elder gravelly sandy loam, 0 to 1 percent slopes

B 26.4 51.7%

119 Still clay, 0 to 2 percent slopes

C 3.3 6.4%

134 Toags gravelly coarse sand, 2 to 9 percent slopes

A 3.8 7.4%

142 Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

A 17.6 34.5%

Totals for Area of Interest 51.1 100.0%

Hydrologic Soil Group—Pinnacles National Monument, California Pinnacles

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Description

Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms.

The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows:

Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.

Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture.

These soils have a moderate rate of water transmission.

Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.

Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission.

If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Hydrologic Soil Group—Pinnacles National Monument, California Pinnacles

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

RUSLE2 Related Attributes

This report summarizes those soil attributes used by the Revised Universal Soil Loss Equation Version 2 (RUSLE2) for the map units in the selected area. The report includes the map unit symbol, the component name, and the percent of the component in the map unit. Soil property data for each map unit component include the hydrologic soil group, erosion factors Kf for the surface horizon, erosion factor T, and the representative percentage of sand, silt, and clay in the mineral surface horizon. Missing surface data may indicate the presence of an organic surface layer. .

Report—RUSLE2 Related Attributes

Soil properties and interpretations for erosion runoff calculations. The surface mineral horizon properties are displayed. Organic surface horizons are not displayed.

RUSLE2 Related Attributes–Pinnacles National Monument, California

Map symbol and soil name Pct. of map unit

Slope length

(ft)

Hydrologic group Kf T factor Representative value

% Sand % Silt % Clay

117—Elder gravelly sandy loam, 0 to 1 percent slopes

Elder 80 — B .17 4 65.9 19.1 15.0

119—Still clay, 0 to 2 percent slopes

Still 80 — C .24 5 26.1 28.9 45.0

134—Toags gravelly coarse sand, 2 to 9 percent slopes

Toags 70 — A .10 5 78.5 16.5 5.0

142—Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

Ordeal 40 — A .24 3 78.5 16.5 5.0

Longsfolly 35 — A .17 4 78.5 16.5 5.0

Passion 15 — D .20 2 78.5 16.5 5.0

Data Source Information

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

RUSLE2 Related Attributes---Pinnacles National Monument, California Pinnacles

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Drainage Class—Pinnacles National Monument, California

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/26/2018

666440 666520 666600 666680 666760 666840 666920 667000 667080 667160 667240

666440 666520 666600 666680 666760 666840 666920 667000 667080 667160 667240

36° 30' 51'' N

1°

' 2 9'

' W 36° 30' 51'' N

1°

' 5

6' ' W

36° 30' 34'' N

1°

' 2

9' ' W

36° 30' 34'' N

1°

' 5

6' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 150 300 600 900

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

Excessively drained

Somewhat excessively drained Well drained

Moderately well drained

Somewhat poorly drained

Poorly drained

Very poorly drained

Subaqueous

Not rated or not available

Soil Rating Lines Excessively drained

Somewhat excessively drained Well drained

Moderately well drained

Somewhat poorly drained

Poorly drained

Very poorly drained

Subaqueous

Not rated or not available

Soil Rating Points

Excessively drained

Somewhat excessively drained Well drained

Moderately well drained

Somewhat poorly drained

Poorly drained

Very poorly drained

Subaqueous

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 31, 2009—Mar 1, 2017

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Drainage Class—Pinnacles National Monument, California (Pinnacles)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Drainage Class

117 Elder gravelly sandy loam, 0 to 1 percent slopes

Well drained 26.4 51.7%

119 Still clay, 0 to 2 percent slopes

Well drained 3.3 6.4%

134 Toags gravelly coarse sand, 2 to 9 percent slopes

Somewhat excessively drained

3.8 7.4%

142 Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

Somewhat excessively drained

17.6 34.5%

Totals for Area of Interest 51.1 100.0%

Description

"Drainage class (natural)" refers to the frequency and duration of wet periods under conditions similar to those under which the soil formed. Alterations of the water regime by human activities, either through drainage or irrigation, are not a consideration unless they have significantly changed the morphology of the soil.

Seven classes of natural soil drainage are recognized-excessively drained, somewhat excessively drained, well drained, moderately well drained, somewhat poorly drained, poorly drained, and very poorly drained. These classes are defined in the "Soil Survey Manual."

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Drainage Class—Pinnacles National Monument, California Pinnacles

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Depth to Any Soil Restrictive Layer—Pinnacles National Monument, California (Pinnacles Restrictive)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/19/2018

664500 664800 665100 665400 665700 666000 666300 666600 666900 667200 667500

664500 664800 665100 665400 665700 666000 666300 666600 666900 667200 667500

36° 30' 8'' N

1°

' 5 2'

' W 36° 30' 8'' N

1°

' 4

0' ' W

36° 28' 58'' N

1°

' 5

2' ' W

36° 28' 58'' N

1°

' 4

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 500 1000 2000 3000

Feet 0 200 400 800 1200

Meters Map Scale: 1:15,000 if printed on A landscape (11" x 8.5") sheet.

Area of Interest (AOI)

Soils Soil Rating Polygons

0 - 25

25 - 50

50 - 100

100 - 150

150 - 200

> 200

Not rated or not available

Soil Rating Lines 0 - 25

25 - 50

50 - 100

100 - 150

150 - 200

> 200

Not rated or not available

Soil Rating Points 0 - 25

25 - 50

50 - 100

100 - 150

150 - 200

> 200

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 31, 2009—Mar 1, 2017

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Depth to Any Soil Restrictive Layer—Pinnacles National Monument, California (Pinnacles Restrictive)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/19/2018

Depth to Any Soil Restrictive Layer

Map unit symbol Map unit name Rating (centimeters) Acres in AOI Percent of AOI

101 Ordeal-Passion- Badlands association, 50 to 100 percent slopes

54 0.3 0.1%

114 Ordeal-Tuborcio- Passion complex, 20 to 50 percent slopes

75 85.5 27.3%

117 Elder gravelly sandy loam, 0 to 1 percent slopes

>200 42.4 13.6%

120 Elder coarse sandy loam, 1 to 3 percent slopes

>200 2.8 0.9%

128 Still-Riverwash complex, 0 to 2 percent slopes

>200 75.9 24.3%

133 Toags-Pinncamp complex, 0 to 5 percent slopes

>200 3.0 1.0%

136 Oxyaquic Haploxerolls, 0 to 1 percent slopes

>200 1.8 0.6%

142 Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

92 100.8 32.2%

Totals for Area of Interest 312.5 100.0%

Description

A "restrictive layer" is a nearly continuous layer that has one or more physical, chemical, or thermal properties that significantly impede the movement of water and air through the soil or that restrict roots or otherwise provide an unfavorable root environment. Examples are bedrock, cemented layers, dense layers, and frozen layers.

This theme presents the depth to any type of restrictive layer that is described for each map unit. If more than one type of restrictive layer is described for an individual soil type, the depth to the shallowest one is presented. If no restrictive layer is described in a map unit, it is represented by the "> 200" depth class.

This attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used.

Depth to Any Soil Restrictive Layer—Pinnacles National Monument, California Pinnacles Restrictive

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Rating Options

Units of Measure: centimeters

Aggregation Method: Dominant Component

Component Percent Cutoff: None Specified

Tie-break Rule: Lower

Interpret Nulls as Zero: No

Depth to Any Soil Restrictive Layer—Pinnacles National Monument, California Pinnacles Restrictive

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Hydrologic Soil Group—Pinnacles National Monument, California (Pinnacles Hydrologic)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/19/2018

664500 664800 665100 665400 665700 666000 666300 666600 666900 667200 667500

664500 664800 665100 665400 665700 666000 666300 666600 666900 667200 667500

36° 30' 8'' N

1°

' 5 2'

' W 36° 30' 8'' N

1°

' 4

0' ' W

36° 28' 58'' N

1°

' 5

2' ' W

36° 28' 58'' N

1°

' 4

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 500 1000 2000 3000

Feet 0 200 400 800 1200

Area of Interest (AOI)

Soils Soil Rating Polygons

A

A/D

B

B/D

C

C/D

D

Not rated or not available

Soil Rating Lines A

A/D

B

B/D

C

C/D

D

Not rated or not available

Soil Rating Points A

A/D

B

B/D

C

C/D

D

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 31, 2009—Mar 1, 2017

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Hydrologic Soil Group—Pinnacles National Monument, California (Pinnacles Hydrologic)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Hydrologic Soil Group

101 Ordeal-Passion- Badlands association, 50 to 100 percent slopes

B 0.3 0.1%

114 Ordeal-Tuborcio- Passion complex, 20 to 50 percent slopes

B 85.5 27.3%

117 Elder gravelly sandy loam, 0 to 1 percent slopes

B 42.4 13.6%

120 Elder coarse sandy loam, 1 to 3 percent slopes

B 2.8 0.9%

128 Still-Riverwash complex, 0 to 2 percent slopes

C 75.9 24.3%

133 Toags-Pinncamp complex, 0 to 5 percent slopes

A 3.0 1.0%

136 Oxyaquic Haploxerolls, 0 to 1 percent slopes

C/D 1.8 0.6%

142 Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

A 100.8 32.2%

Totals for Area of Interest 312.5 100.0%

Hydrologic Soil Group—Pinnacles National Monument, California Pinnacles Hydrologic

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Description

Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms.

The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows:

Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.

Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture.

These soils have a moderate rate of water transmission.

Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.

Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission.

If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Hydrologic Soil Group—Pinnacles National Monument, California Pinnacles Hydrologic

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

RUSLE2 Related Attributes

This report summarizes those soil attributes used by the Revised Universal Soil Loss Equation Version 2 (RUSLE2) for the map units in the selected area. The report includes the map unit symbol, the component name, and the percent of the component in the map unit. Soil property data for each map unit component include the hydrologic soil group, erosion factors Kf for the surface horizon, erosion factor T, and the representative percentage of sand, silt, and clay in the mineral surface horizon. Missing surface data may indicate the presence of an organic surface layer. .

Report—RUSLE2 Related Attributes

Soil properties and interpretations for erosion runoff calculations. The surface mineral horizon properties are displayed. Organic surface horizons are not displayed.

RUSLE2 Related Attributes–Pinnacles National Monument, California

Map symbol and soil name Pct. of map unit

Slope length

(ft)

Hydrologic group Kf T factor Representative value

% Sand % Silt % Clay

101—Ordeal-Passion- Badlands association, 50 to 100 percent slopes

Ordeal 50 — B .28 3 66.9 23.1 10.0

Passion 30 — D .20 2 78.5 16.5 5.0

114—Ordeal-Tuborcio-Passion complex, 20 to 50 percent slopes

Ordeal 40 — B .24 3 67.8 22.2 10.0

Tuborcio 35 — C .17 3 68.6 19.4 12.0

Passion 15 — D .32 2 78.5 16.5 5.0

117—Elder gravelly sandy loam, 0 to 1 percent slopes

Elder 80 — B .17 4 65.9 19.1 15.0

120—Elder coarse sandy loam, 1 to 3 percent slopes

Elder 80 — B .20 5 70.0 23.0 7.0

128—Still-Riverwash complex, 0 to 2 percent slopes

Still 70 — C — 5 — — 0.0

133—Toags-Pinncamp complex, 0 to 5 percent slopes

Toags 50 — A .10 5 87.0 10.0 3.0

Pinncamp 30 — A — 5 — — 0.0

RUSLE2 Related Attributes---Pinnacles National Monument, California Pinnacles Composition

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

RUSLE2 Related Attributes–Pinnacles National Monument, California

Map symbol and soil name Pct. of map unit

Slope length

(ft)

Hydrologic group Kf T factor Representative value

% Sand % Silt % Clay

136—Oxyaquic Haploxerolls, 0 to 1 percent slopes

Oxyaquic Haploxerolls, ponded

90 — C/D .24 5 26.1 28.9 45.0

142—Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

Ordeal 40 — A .24 3 78.5 16.5 5.0

Longsfolly 35 — A .17 4 78.5 16.5 5.0

Passion 15 — D .20 2 78.5 16.5 5.0

Data Source Information

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

RUSLE2 Related Attributes---Pinnacles National Monument, California Pinnacles Composition

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Drainage Class—Pinnacles National Monument, California

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/19/2018

664500 664800 665100 665400 665700 666000 666300 666600 666900 667200 667500

664500 664800 665100 665400 665700 666000 666300 666600 666900 667200 667500

36° 30' 8'' N

1°

' 5 2'

' W 36° 30' 8'' N

1°

' 4

0' ' W

36° 28' 58'' N

1°

' 5

2' ' W

36° 28' 58'' N

1°

' 4

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 500 1000 2000 3000

Feet 0 200 400 800 1200

Area of Interest (AOI)

Soils Soil Rating Polygons

Excessively drained

Somewhat excessively drained Well drained

Moderately well drained

Somewhat poorly drained

Poorly drained

Very poorly drained

Subaqueous

Not rated or not available

Soil Rating Lines Excessively drained

Somewhat excessively drained Well drained

Moderately well drained

Somewhat poorly drained

Poorly drained

Very poorly drained

Subaqueous

Not rated or not available

Soil Rating Points

Excessively drained

Somewhat excessively drained Well drained

Moderately well drained

Somewhat poorly drained

Poorly drained

Very poorly drained

Subaqueous

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinnacles National Monument, California Survey Area Data: Version 6, Sep 11, 2017

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 31, 2009—Mar 1, 2017

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Drainage Class—Pinnacles National Monument, California (Pinnacles)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Drainage Class

101 Ordeal-Passion- Badlands association, 50 to 100 percent slopes

Somewhat excessively drained

0.3 0.1%

114 Ordeal-Tuborcio- Passion complex, 20 to 50 percent slopes

Somewhat excessively drained

85.5 27.3%

117 Elder gravelly sandy loam, 0 to 1 percent slopes

Well drained 42.4 13.6%

120 Elder coarse sandy loam, 1 to 3 percent slopes

Well drained 2.8 0.9%

128 Still-Riverwash complex, 0 to 2 percent slopes

Well drained 75.9 24.3%

133 Toags-Pinncamp complex, 0 to 5 percent slopes

Somewhat excessively drained

3.0 1.0%

136 Oxyaquic Haploxerolls, 0 to 1 percent slopes

Somewhat poorly drained

1.8 0.6%

142 Ordeal-Longsfolly- Passion complex, 9 to 50 percent slopes

Somewhat excessively drained

100.8 32.2%

Totals for Area of Interest 312.5 100.0%

Description

"Drainage class (natural)" refers to the frequency and duration of wet periods under conditions similar to those under which the soil formed. Alterations of the water regime by human activities, either through drainage or irrigation, are not a consideration unless they have significantly changed the morphology of the soil.

Seven classes of natural soil drainage are recognized-excessively drained, somewhat excessively drained, well drained, moderately well drained, somewhat poorly drained, poorly drained, and very poorly drained. These classes are defined in the "Soil Survey Manual."

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Drainage Class—Pinnacles National Monument, California Pinnacles

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

G:\Siegel_Strain-1961\196117006-Pinnacles NP East Entrance Station\_DOCS\Reports\Draft Percolation Testing Technical Memo.docx

EXHIBIT C – SOIL PROFILE LOGS