vdot soils and aggregate compaction pdf vdot soils and aggregate compaction pdf

2016v1.0 Chapter 4 19, APPENDIX K PIPE INSPECTION **Virginia Test Method 123** Post Installation Inspection of Buried Storm Drain Pipe and Pipe Culverts June 25, 2010 SCOPE For all roadway projects that are constructed by private, SECTION 55 PIPE FOR STORM DRAINS AND CULVERTS (FAA D-701) 55-1 GENERAL The Contractor shall perform all work required by the plans for construction of pipe for storm drains, precast polymer trench drains, State of Illinois Department Of Transportation CONSTRUCTION INSPECTOR S CHECKLIST FOR STORM SEWERS While its use is not required, this checklist has been prepared to provide the field inspector a summary, SECTION 724 PIPE CULVERTS 724.1 Description. 10) What is the maximum backfill lift thickness? - 2000, Related Features The diameter of the mandrel at any point shall not be less than the allowable percent deflection of the certified actual mean diameter of the pipe or culvert being tested. Fully insert pipe. This website includes hyperlinks to sites neither controlled nor sponsored by VDOT or the Commonwealth of Virginia. SECTION 014500 QUALITY CONTROL PART 1 GENERAL 1.01 RELATED REQUIREMENTS A. Dense graded means that the particles in the mixture are sized do that they fill most of the voids; there is very little space between the soil or stone particles. Backfill material shall be knifed into the area along the bottom edge of the pipe. This course includes downloadable resources including a procedural outline and a pdf of the standard, instructional video content, interactive knowledge checks, and a self . or structures. In a flexible pipe this zone must protect the pipe from distortions due to loading extend to 12 above pipe. The top few inches should be slightly yielding (loose) and fill the corrugations. In the top 5 feet; perform one test every other lift around the perimeter and continue to the top of the structure. A. # u hYoF#4rPzL@]Gb)3d@pa@sc/IK^0@Qq. Links may open in a new window. Students must bring valid ID & attend class in order to test. The CCWA is hosting the following courses, which are available in a traditional (instructor-led) format or as a self-study option, allowing the students to challenge the Materials Certification exams: For more information on CCWA courses and registration click hereor contact CCWA at 804-523-2290 or 804-523-2292. All new construction involves a study and analysis of the on-site soils. 12) Backfill is usually placed loosely and heaped above the finished level. 5) Open only as much trench as can be safely maintained by available equipment. 1103 POINT REPAIRS AND OBSTRUCTION REMOVALS, Storm Sewer Trenchless Upgrade Alternatives and Recommendations, SECTION 32 14 13.19 PERMEABLE INTERLOCKING CONCRETE PAVEMENT (1995 MasterFormat Section 02795). True or false: A soil that contains a high percentage of fines is more affected by water that one with a low percentage of fines. True. 57 stone MUST be capped with a minimum of 4 crusher run prior to placement of pipe or box culvert. Trench widths may be varied, based on the competency of the in situ soil, backfill materials, compaction levels and loads. The contractor shall be responsible for repairing any damages, Specifications for Residential Property Owners Connection to New Public Sewer Spalding Tract property owners are required to connect to the community sewer system when construction is complete and the, SECTION INCLUDES Domestic Water Fire Water Service Water Well Sanitary Sewer Storm Drains Foundation Drainage RELATED SECTIONS 03 30 00 Concrete 21 00 00 Fire Suppression - Sprinklers 22 00 00 Plumbing, SECTION 200: STORM SEWER CONSTRUCTION STANDARDS Page No. True or false: Open graded aggregates are used in pavement to give the structure more strength. M`RyK?77&kr7#q*Xg`QU0iFfu{8nWW0-dNGC2lC8IA]uuLq\_gyxlP%n%[et:eR%iXebrq-b#[3'mAgh*ofmYe`4"7ex2j-RUi*LBI+KIyU9/S(zh2=m6|Em0.oaIvJI>a$ACDMSDq;~7Qj=i~=+eV39CB9vq,v=WTusaO.TVDP)v`y':PsASO&QePN27=RffF)fM{IUY_82 9Z0:}t8hc>C[U\sDK lUh"(o) 0N*5"ziE^ Yr*bgubM@/6Elg[r9o0p ;I(|)sX\(v2r. When joining pipe: Begin at the downstream end (Bell faces upstream) Ensure spigot and bell are clean and free of debris Properly lubricate spigot and bell with pipe lubricant Is Contractor aware of the maximum insertion angle? 8 in. 19 terms. Summary B. Submittals C. Site Information D. Sewer Pipe and Fittings E. Lateral Locations F. Lateral Installation G. Inspection Tee Installation H. Removal, SECTION 02630 PART 1 - GENERAL 1.01 DESCRIPTION A. This program will encompass nuclear density testing, one-point proctor and "Speedy" moisture, construction and testing of embankments and subgrade, pipe installation, roller patterns and reports. Locate Utilities Prior to excavating the trench area, all utilities should be located by a qualified contractor. Proper installation is essential to pavement performance as it increases bearing capacity, increases service life and lowers maintenance costs. %PDF-1.5 % The proctored 1 hour, 1-on-1 proficiency test is required to fully complete the VDOT Soils & Aggregate Compaction certification. Pipe Testing Frequency Example 1: Pipe Diameter = 48 in. CADD Manual. OPEN CHANNELS 6 Index inlet protection excavated drop inlet protection (Temporary) 6.50.1 HARDWARE CLOTH AND GRAVEL INLET PROTECTION Block and gravel inlet Protection (Temporary) sod drop inlet protection ROCK DOUGHNUT, SECTION 32: SANITARY SEWER INSTALLATION 32-01 SCOPE. = 12 lifts 3) 12 lifts 1 lift (skip first lift) = 11 lifts 4) 11lifts 4 (test every fourth compacted lift) = 2.75, round up to 3 tests in bottom 4 ft. of backfill Top 5 ft. of backfill x 3 lifts/ft. <>/Metadata 1689 0 R/ViewerPreferences 1690 0 R>> PDF SOILS COMPACTION AND TESTING 2015 - Iowa Department of Transportation Alternative Project Delivery | Construction| Cost Estimation Office| Local Assistance |Location and Design | Maintenance |Materials |Office of Land Use | Operations | Project Management Office | Right of Way/Utilities | Structure and Bridge |Traffic Engineering | Transportation and Mobility Planning. STORM SEWER CALCULATIONS 7-4 7.6. Furnish and install culvert pipe, entrance pipe, and storm sewer pipe. STORM SEWERS 402.01. Silt and clay are made up of particles smaller than the No. This section includes all labor, materials, equipment, and incidentals required and installation of Polyvinyl Chloride, STANDARD SPECIFICATIONS SECTION 03461 PRECAST REINFORCED CONCRETE MANHOLES AND MANHOLE BASES PART 1 - GENERAL A. waste aggregate )-4CWP( 4% ceramic waste pow der) represents a 10% aggregate substitution with ceramic waste. Construction Materials Testing Soils - NICET Pipe should be stored in an out of the way location where it will not be damaged. Use units conforming to the dimensions, SECTION 33 05 16.13 PRECAST CONCRETE PART 1 - GENERAL 1.01 SECTION INCLUDES A. For more information about taking the . For registration assistance, questions or concerns, please contact: The MCS courses are currentlybeing delivered through a partnership between VDOT, the Virginia Education Center for Asphalt Technology (VECAT) with Germanna Community College (GCC)and the Community College Workforce Alliance (CCWA). PDF Appendix D - Virginia Test Methods (REVISED) Copyright 2023, VDOT. As stated earlier, soils are made up of many different types, shapes and sizes of particles. CHAPTER 4 STUDY QUESTIONS 2) True or False. large void spaces and is loosely compacted. Place sample in container and weigh. These heavy loads can cause considerable damage in flexible pipes and can cause D load cracking in rigid pipes. All cracks shall be digitally scanned to allow for accurate measurement. Conducts and/or observe and document test on soils, asphalt, concrete, aggregates, bituminous products, metal products and industrial coatings. Manhole Backfill Frequency Example: Depth of Backfill = 9 feet Depth of Backfill (ft.) 5 ft. = Depth of Backfill below top 5 feet 1) 9 ft. 5 ft. = 4 ft. 2) 4 ft. x 3 lifts/ft. (don t test 1st compacted lift) = 104 in. VDOT Soils and Aggregate Compaction: Chapter 2. It is generally easier to install due to less stringent lubrication requirements for the gasket. From this we can highlight the following requirements: Visual/ Video Inspection is required on: All Storm Sewer Pipes (100%) Selected Number of Pipe Culverts (>10%) 2016v1.0 Chapter 4 15, 16 Must be done with VDOT Rep Present Conducted no sooner than 30 days after completion of Installation and placement of final cover (except pavement). PDF Aashto Soil Classification Sheets - hldm4.lambdageneration.com VDOT Materials Certification Schools - Business | Virginia Department Test pattern is to begin after the first 4 lift above bedding and continue to 1 foot above top of the pipe. Describe recommended installation procedures 4. For assistance printing or verifying your Materials Certifications Report use this click here. Drawings and general provisions of Contract, including General and Supplemental Conditions and Division 1 Specification Sections, 551.01 550 PIPE CULVERTS, SEWERS AND DRAINS 551 GENERAL 551.01 Description 551.02 Materials 551.03 Excavation 551.04 Protection of Excavation 551.05(a) Bedding for Rigid Pipe 551.05(b) Bedding for Non-Rigid, How To Retaining Wall Guide Before you start: Consents and Engineering Building Consent Retaining walls over 1.5m high will require a building consent from the Local Body Council. Conditions of Use Type of Inlet Protection, INSTALLATION GUIDE americanwick.com 800.242.WICK (9425) American Wick Drain SITEDRAIN prefabricated drainage products may be installed in a variety of civil construction applications including: retaining. Fillable Online VDOT Soils and Aggregate Compaction Fax Email Print See the following table for VDOT recommendations. The specific locations are shown on the plans. In a rigid pipe, this zone has zero effect on the load carrying capacity. Applications for a zoning district map amendment (rezoning), conditional rezoning, planned development, or conditional use permit shall include a VDOT traffic impact statement (VTIS), and applications for a site plan or preliminary plat shall include a traffic impact statement (TIS), where the proposed development is reasonably anticipated to . Refer to VDOT Road and Bridge Specifications, Section Procedures (d) Post Installation Inspection for detail requirements and remediation procedures. Your one-stop source for VDOT maps, data and project info. hbbd``b`~$CC`LZ eQ@dq ;&F d}0 False. Pollution Prevention Field Guide for Construction Activities. <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/Annots[ 11 0 R 12 0 R 21 0 R 25 0 R 31 0 R 32 0 R 33 0 R 34 0 R 47 0 R 48 0 R 49 0 R 50 0 R 51 0 R 52 0 R 53 0 R 54 0 R 55 0 R 56 0 R 57 0 R 60 0 R 61 0 R 62 0 R 63 0 R 64 0 R 65 0 R 66 0 R 67 0 R] /MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> materials (soils, aggregate and asphalt) in the field, the Geotechnical firm shall be responsible for the continuous monitoring of the placement and compaction of aggregate base materials, asphalt concrete pavement and the placement and compaction of earthwork and backfill of trenches and structures to ensure compliance with the Specifications. Currently VDOT certified or Mid Atlantic Regional Technician Program (MARTCP) in the following disciplines: - Expected VDOT Certifications Soil and Aggregate Field Compaction Asphalt Field Hydraulic Cement Concrete Field Pavement Marking Flagger Certification Certification & Issuing Agency Soil and Aggregate Compaction - VDOT or NICET LEVEL II* Bethel Township Municipal Authority (BTMA) RESIDENTIAL SEWER CONNECTION MANUAL. SECTION 02630 STORM DRAINAGE PART 1 - GENERAL 1.01 RELATED DOCUMENTS A. 15) What end of the pipe system do you start installation? Public Involvement Manual. Some links may require the Adobe Reader. What is the moisture content at which soil begins to behave like a liquid called? San Antonio Water System Standard Specifications for Construction ITEM NO. Structural Fill See Section (A)(2)(g) of the Road and Bridge Specifications for complete requirements for backfill material. There are many types of compaction equipment available. Importance to Maintenance & Water Quality. AASHTO T180 The Moisture Density Relations of Soils using a 10-pound Rammer and an 18-inch drop. This happens because large pores more effectively move water downward through . 5) True or False. At the engineer of record's. 0 10) Backfill the trench using clean #8 or #57 aggregate as soon as practical, but not later than the end of each working day. Inspect how the pipe is being stored on site to ensure no damage is being done to the pipe prior to installation. Materials. All materials and workmanship, TABLE OF CONTENTS NO. 18) What is the minimum amount of cover over pipe to prevent damage from construction loads? 5.01 Design, PROJECT COST ESTIMATE ASSUMPTIONS AND EXCLUSIONS, SPECIFICATIONS FOR SEWER PIPE AND LINING INSERTION - TRENCHLESS; GENERAL GUIDELINES (As Provided by NASSCO), TECHNICAL NOTE Culvert Sliplining and Lining of Casings with HPPipe. endobj 794 (d), please call 800-367-7623. Debris in the pipe Coatings free of cracks, scratches and peeling Cracks (longitudinal and circumferential) Spalls and Slabbing For metal and plastic pipe localized buckling, bulging, cracking at bolt holes, flattening, or racking, etc. SECTION 02150 REMOVAL OR ABANDONMENT OF EXISTING UTILITIES AND UNDERGROUND STRUCTURES. True. 2) Mechanical compacting ram: If a mechanical compacting ram is used, it must be calibrated to produce results Try Now! J\b 0). 0 1. Where applicable, pulleys may be incorporated into the system to change the direction of pull so that inspection personnel need not physically enter the pipe, culvert or manhole. SCOPE Pipe subsoil drains shall be constructed in accordance with this specification and in conformity with the lines, grades and cross-sections shown, 402.02 Section 402. Cleaning, Inspecting, and Testing Storm Sewers C. Cleaning and, SECTION 33 41 13 PUBLIC STORM PART 1 - GENERAL 1.01 SECTION INCLUDES A. 2. %%EOF Description Storm drainage structure construction shall include, but not necessarily be limited to, furnishing and installing or, Installation PowerPoint for Grasscrete Formers 1 This document describes the two single-use tools utilized to create the Grasscrete product. This type of joint provides a leak resistant joint when a profile gasket is used. Proper haunching provides support to ensure the pipe s strength is achieved. aggregate from the same source, or break up the material . A compacted soil has a reduced rate of both water infiltration and drainage. VDOT Soils and Aggregate Compaction Flashcards | Quizlet 2e\o ngV10J6q`pp)|Hpm3@BF > endobj 298 0 obj <> endobj 299 0 obj <>stream Concrete Field 1. Senior Transportation Construction Inspector to join us in VDOT's Northern Virginia to inspect all phases of construction on highway construction and maintenance projects.To oversee, monitors . It is not appropriate to leave a bench of native soil alongside the pipe during construction. The video camera inspection is to be conducted with a VDOT representative present. Deficiencies found may include: but are not limited to, the following: Crushed, collapsed or deformed pipe or joints Alignment defects Improper Joints (allow infiltration of soil) Misaligned joints (allow debris accumulation) Pipe Penetrations (guardrails, utilities, etc.) Testing is no longer mandatory on the last day of class. 3. Unsuitable foundations must be stabilized at the engineer s direction. Additional temporary fill is needed to protect the pipe from construction loads. Trenching should be completed in existing soils with sidewalls reasonably vertical to the top of the pipe. SECTION 02720 SANITARY SEWER AND STORM DRAIN SYSTEMS, Ohio Department of Transportation Division of Production Management Office of Geotechnical Engineering. 2016v1.0 Chapter 4 14, 15 POST INSTALLATION INSPECTION The following is an excerpt from Virginia Test Method 123 Post Installation Inspection of Buried Storm Drain Pipe and Pipe Culverts covering the scope of post installation pipe inspection. 295 0 obj <>/Filter/FlateDecode/ID[<8B56AE6A42E26944BC3979D310C9B904>]/Index[282 27]/Info 281 0 R/Length 72/Prev 509365/Root 283 0 R/Size 309/Type/XRef/W[1 2 1]>>stream back to courses page. 11) Backfill depth is at least equal to the diameter of the pipe. 57 stone is not required; seat stone in trench. Location B. Sizing TABLE OF CONTENTS 08020 MATERIALS A. A copy of the Storm Sewer/Culvert Inspection Report (inspection report)including any video tape/digital Video Recording (DVD)/digital photographs shall be provided to the VDOT Inspector within two business days of the completion of the inspection and made part of the project records. Fine particles are more sensitive to the presence of water than coarse particles. 11 terms. Please click on the course title to see the full course description. 17) What is the minimum amount of cover over pipe allowed for design loads? PDF Appendix E - Proficiency Checklists (REVISED) - Virginia Department of SUBDRAINS AND FOOTING DRAIN COLLECTORS. Request PDF | Advanced fatigue and rutting characterisation of Polish asphalt mixtures based on the VECD model and viscoplastic shift model | The advanced asphalt mixture performance-related . Construction loads often exceed design loads. VDOT Soils and Aggregate Compaction 2016v1.0 Chapter 1 | 1 Unsuitable or unstable foundations may be undercut and replaced with a suitable bedding material, placed in 6 lifts. (test every other 4 in. Portion of Section 2102 . ]1YW'; q=A D0Yf BD0A8 Dh s @!2au28!w)#Nb=` L *w @y7![RYT6 Ke`riO05 ~z SECTION 9.02 BUILDING SUBSURFACE DRAINS (PERIMETER, ETC. SCOPE OF WORK: The work to be performed under the provisions of these documents and the contract based thereon includes furnishing all labor, equipment, materials, To make this website work, we log user data and share it with processors. VECAT,through Germanna Community College (GCC), is hosting the following courses, which are now available either online or in a face to face format: For more information on courses and registration click here or contact Judith Calvert, 540-937-6757. Your one-stop source for VDOT maps, data and project info. When backfill is below spring line of pipe, compact next to pipe first and work towards the trench wall. 55 terms. For written and proficiency exams, contact the community colleges to schedule either an in-person or remote exam. Grades and certifications are issued within 15-30 business days after the testing date. This zone contains the same select quality backfill material as in the haunch zone for flexible pipe. SANITARY SEWER SPECIFICATIONS OCTOBER 2003 HARVEST-MONROVIA WATER, SEWER, AND FIRE PROTECTION AUTHORITY SECTION 1.00 1.10 Purpose The purpose of this document is to assemble the sewer specifications, policies, SEDIMENT/STORMWATER MANAGEMENT BASIN CONSTRUCTION CHECKLIST For permanent structures per Delaware SCS Pond Code 378 and Delaware Sediment and Stormwater Regulations KEY PROJECT INFORMATION Item meets standard, LS 2540 SEWER LATERALS AND INSPECTION TEES A. VDOT: Soils and Aggregate Compaction. Rock more than 2 inches in its greatest dimension shall not be placed within 12 inches of pipe. endstream endobj startxref 13) Use vibratory plate with a welded foot to compact the aggregate backfill. Cracks shall be digitally scanned to allow for accurate measurement. General: Submit the following in accordance with The General Conditions. Rubber gaskets may be used when the joint slope is five degrees or less, however it is usually limited to mastic or butyl sealants. What are those two functions? SUMP DRAINS 7-3 7.3. (PDF) Recycled Concrete Aggregated for the use in Roller Compacted Additionally, a copy shall be furnished to local VDOT Asset Management personnel to document the pipe/culvert condition at that point in time. 6) Line the trench with the non woven drainage fabric. When you learn and master soils inspection, your market value shoots up. 1.02 REFERENCE, CLEANING, INSPECTION, AND TESTING OF SEWERS PART 1 - GENERAL 1.01 SECTION INCLUDES A. of the rammer used to compact the soil or soil and aggregate mixture in the mold and the number of layers placed into the compaction mold for compaction. 5) Install pipe to grade 6) Compact structural bedding outside the middle third of the pipe 7) Place structural bedding in lifts 8) Complete structural backfill operation by working from side to side of the pipe, differential not to exceed 24 or 1/3 size of pipe. We developed this course with the input of 30-year inspection managers, engineers, and other industry experts. This program will encompass nuclear density testing, one-point proctor and "Speedy" moisture, construction and testing of embankments and subgrade, pipe installation, roller patterns and reports. The video tape/dvd/digital photographs should be of such clarity, detail and resolution as to clearly show the conditions of the interior of the pipe/culvert and detect any defects within the pipe or culvert as specified herein. 1. Having one of these functions without the other is worthless. Storm drainage piping, fittings, and accessories at proposed station areas and locations other than under and immediately adjacent, Beacon Hill Sewer District Standard Specifications Residential Gravity Side Sewer Including Design Criteria and Standard Construction Drawings Residential Gravity Side Sewer Design Criteria 1. CATCH BASINS 7-3 7.4. % Table of Contents, STANDARD SPECIFICATIONS FOR PRIVATE BUILDING SEWER LINES IN PUBLIC RIGHT-OF-WAY, STANDARD SPECIFICATIONS & CONSTRUCTION DETAILS MANUAL SECTION 5 - STORM DRAINAGE. Soils and Aggregate Compaction Homework.pdf - Course Hero 1. Bierolson. TABLE OF CONTENTS. A mandrel is needed for Flexible Pipe to measure deflection. Web Policy / Privacy Statement / WAI Compliance / Email Safety / Site Map, Click here to access guidelines for the VDOT Materials Certification Schools Program (Section 114, Manual of Instructions), ACI Concrete Field Testing Technician Certification Program Schedule, Nuclear Radiation Certifications can now be obtained online through third party vendors, Pavement Marking (only available as an online course), Asphalt Plant Level 1 - Physical demonstration of proficiency -scheduled byGermanna CC, Asphalt Plant Level 2 - Physical demonstration of proficiency - scheduled by Germanna CC, Asphalt Plant Mix Design - Physical demonstration of proficiency - scheduled by Germanna CC, Concrete Field - Current ACI must be submitted to, Soils and Aggregate Compaction - Physical demonstration of proficiency - scheduled by CCWA. The following shall serve as the minimum requirements for contractors performing work in relation to the Authority s potable water and sanitary sewer system(s), appurtenances and service connections. The above components are designed to perform three functions to aid in draining water from the pavement; these are: Intercept Collect Discharge Following is a general guide on the installation of underdrain/edge drain systems: 1) Excavate trench making sure the side walls are stable 2) Remove any sloughed materials from the trench 3) The dug out material is picked up with conveyor belt and loaded in trucks or piled on one side then picked up by a front end loader. CITY AND COUNTY OF DENVER ENGINEERING DIVISION Wastewater Capital Projects Management Standard Construction Specification 10.1 Precast Concrete Pipe 10.1.1 General This section covers material requirements, DIVISION 4300 STORM DRAINAGE SECTION 4305 STORM SEWER PART 1 - GENERAL 1.01 SCOPE This section covers the construction of storm sewers for the collection and transport of stormwater runoff. These guidelines are applicable to the locating, marking, SECTION 5 - STORM DRAINAGE 5.01 Design Storm drainage facilities shall be designed in accordance with the goals and guidelines set forth in the Unified Development Ordinance. 57 stone be used? June 13th, 2018 - AASHTO AASHTO The AASHTO classification Classification of soils and soil aggregate mixtures for AASHTO system Or use comparable reference Guide Sheet 1 see Get the free VDOT Soils and Aggregate Compaction Description . False. Students must bring valid ID & attend class in order to test. Conform to requirements of Section 01 33 00 Submittals. 6) The tolerance on the optimum moisture content at which aggregate must be compacted is 2 percentage points. 1100 SLIP-LINING SANITARY SEWERS 1100.1 DESCRIPTION: This item shall consist of slip-lining sanitary sewer pipe, which is accomplished by pulling or pushing liner pipe into existing sewers by. Clearly the pipe needs to function as a conduit, as the whole idea of a pipe is to move liquid in a controlled manner and direction. Product data for drainage piping specialties. bKjL,gBZqa>,\w In this research work three methods of handling rock sized aggregates which include compacting the whole sample (method . Work includes furnishing and installing precast modular blocks, : Construction Inspection ChecklistsTools Stormwater/Wetland Pond Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: SATISFACTORY/ UNSATISFACTORY COMMENTS Pre-Construction/Materials. Specifications i. When planning a pipeline installation, there are 2 key functions that we must design the pipeline to provide. VDOT: Soils and Aggregate Compaction. Description. This section includes construction of reinforced concrete pipe for storm drainage, culverts, and sanitary sewer, including, BMP: SUBSURFACE DRAIN Definition A perforated conduit such as pipe, tubing or tile installed beneath the ground to intercept and convey ground water.