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Chapter 12 Springs and Wells Part 650 Engineering Field Handbook National Engineering Handbook Chapter 12 Springs and Wells (210–VI–NEH, Amend. 60, July 2012) Chapter 12 Springs and Wells Part 650 National Engineering Handbook Issued draft July 2012 Cover: The spring flows into Onion Creek in Hayes County, Texas The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all pro- grams.) Persons with disabilities who require alternative means for commu- nication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, SW., Washington, DC 20250–9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal op- portunity provider and employer. (210–VI–NEH, Amend. 60, July 2012) Chapter 12 Springs and Wells Contents 650.1200 Introduction 12–1 650.1201 Source of water supply 12–2 (a) Water-bearing materials ................................................................................12–2 (b) Aquifers in the continental United States ..................................................12–3 (c) Effects of geologic structure ........................................................................12–3 (d) Conservation of groundwater resources ....................................................12–4 650.1202 Springs and seeps 12–5 (a) Springs ............................................................................................................12–5 (b) Seeps ...............................................................................................................12–8 (c) Spring design ..................................................................................................12–8 (d) Maintenance .................................................................................................12–16 650.1203 Wells 12–17 (a) Types .............................................................................................................12–17 (b) Site selection ................................................................................................12–21 (c) Hydraulics ....................................................................................................12–22 (d) Design ...........................................................................................................12–23 (e) Construction ................................................................................................12–36 (f) Well development after installation ..........................................................12–36 (g) Testing ...........................................................................................................12–37 (h) Selecting a pump .........................................................................................12–39 (j) Applicable State laws and groundwater rights ........................................12–40 (k) Contracts and specifications ......................................................................12–40 (l) Records .........................................................................................................12–41 (m) Abandonment ...............................................................................................12–41 650.1204 References 12–42 (210–VI–NEH, Amend. 60, July 2012) Chapter 12 Springs and Wells Part 650 National Engineering Handbook Tables Table 12–1 Water-well construction methods and applications 12–19 Table 12–2 Changes in yield with increase in well diameter 12–28 Table 12–3 Guidance on when to use a gravel pack 12–31 Figures Figure 12–1 The hydrologic cycle, with a focus on groundwater 12–1 resources Figure 12–2 Artesian well flowing at surface, Missouri 12–2 Figure 12–3 Principal aquifers of the United States 12–3 Figure 12–4 Groundwater provinces of the United States 12–4 Figure 12–5 Effect of geologic structure on groundwater 12–5 Figure 12–6 Depression spring, seepage or filtration type 12–6 Figure 12–7 Typical contact spring 12–6 Figure 12–8 Springs in jointed sandstone 12–7 Figure 12–9 Springs in jointed basalt 12–7 Figure 12–10 Springs in jointed limestone 12–8 Figure 12–11 Artesian springs at outcrop of aquifer 12–9 Figure 12–12 Spring development in stream channel 12–11 Figure 12–13 Spring collection system 12–12 Figure 12–14 Spring box and pipe arrangement 12–13 12–ii (210–VI–NEH, Amend. 60, July 2012) Chapter 12 Springs and Wells Part 650 National Engineering Handbook Figure 12–15 Hydraulic ram cross section 12–15 Figure 12–16 Water well supplying center-pivot sprinkler irrigation 12–17 system, Idaho Figure 12–17 Sand point used for small diameter driven well 12–18 Figure 12–18 Diagram showing terms used in the water-table aquifer 12–22 formula Figure 12–19 Typical irrigation well in unconsolidated materials 12–23 (see App. A, Glossary) for definition of terms Figure 12–20 Documentation of water-table well design 12–24 Figure 12–21 Documentation of artesian well design 12–25 Figure 12–22 Diagram showing terms used in the artesian aquifer 12–27 formula Figure 12–23 Filter design gradation, based on aquifer particle size 12–32 distribution Figure 12–24 A completed satellite well unit as part of a multiwell 12–33 system Figure 12–25 Typical manifold multiple-well system. Note that the 12–34 pump may be an engine or electric motor Figure 12–26 Sample layouts for manifolds pumping systems 12–35 Figure 12–27 Well interference in an unconfined aquifer 12–35 Figure 12–28 Cross section of developed well showing filter pack and 12–36 well screen Figure 12–29 Relationship between drawdown and yield 12–37 Figure 12–30 Air line for measuring depth to water level 12–38 Figure 12–31 Water well pump powered by electric motor, Washington 12–38 (210–VI–NEH, Amend. 60, July 2012) 12–iii Chapter 12 Springs and Wells Part 650 National Engineering Handbook 12–iv (210–VI–NEH, Amend. 60, July 2012) Chapter 12 Springs and Wells The principal ways of using groundwater are through 650.1200 Introduction spring and well developments. A spring is a natural outflow of water from an underground supply to the ground surface. A seep differs from a spring, in having The purpose of this chapter is to provide conservation- no definite opening. A well (vertical or horizontal) is ists and engineers with some of the fundamentals of a hole drilled, dug, or driven into the earth to obtain planning and developing groundwater resources. The groundwater. chapter contains information that must be considered and analyzed if a successful and long-lasting water For more detailed information, refer to the following supply is to be obtained from wells or springs. The chapters in the U.S. Department of Agriculture (USDA) nature of groundwater, methods of obtaining it from Natural Resources Conservation Service (NRCS) springs or wells, and the development and mainte- National Engineering Handbook (NEH), Part 631: nance of groundwater recovery systems are described. Groundwater has many advantages over water from • Chapter 30, Groundwater Hydrology and Geology other sources, and its economic importance cannot be • Chapter 31, Groundwater Investigations overemphasized. • Chapter 32, Well Design and Spring Development The term “groundwater” is a simplistic term that • Chapter 33, Groundwater Recharge encompasses water in the saturated zone beneath the Earth’s surface, water that is under pressure, and the For springs, see the NRCS National Conservation complex movement of groundwater as an integral part Practice Standard (CPS), Code 574, Spring of the Earth’s hydrologic cycle, as depicted in figure Development. For wells, see the CPS Code 642, Water 12–1. Well. Figure 12–1 The hydrologic cycle, with a focus on groundwater resources Precipitation Recharge Evaporation area Artesian Runoff (fissure) Transpiration spring Perched water table Water table Artesian pressure surface Flowing Water well Evaporation table artesian well Infiltration (recharge) Fault Gravity (Seepage) springs Artesian Water table Lake Runoff Water table (unconfined) W aquifer ater table Nonflowing Groundwater flow Ocean artesian well Salt (Confined) water Aquifer Impermeable rock (210–VI–NEH, Amend. 60, July 2012) Chapter 12 Springs and Wells Part 650 National Engineering Handbook Groundwater is located in the area of the Earth’s crust known as the zone of saturation and is contained in 650.1201 Source of water aquifers: water table aquifers, confined aquifers, or perched aquifers. supply In a water table aquifer, the water is not confined, is at atmospheric pressure, and may rise or fall in the upper (a) Water-bearing materials zone of saturation, depending on rate of recharge and rate of withdrawal, drainage, or outflow. In a confined Although underground streams may flow in cavernous aquifer, the water is confined in the zone of saturation limestone or lava tubes, the main source of groundwa- by an overlying relatively impermeable layer and may ter in rock formations is the pores and cracks. be at a pressure greater than atmospheric. If the water in a confined aquifer rises above the containing layer Unconsolidated sands or gravels
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