05_DILG_Salintubig - Source Development

7/28/2019 05_DILG_Salintubig - Source Development

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Water

Cycle

WATER VAPOR

RAIN CLOUDS

RAINFALL

MOUNTAIN AND

RIVERS

OCEAN

LAKES

GROUNDWATER


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Groundwater Flow Problems


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Groundwater Flow Problems


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SPRING DEVELOPMENT:

Confirmed sufficient(dependable) yield

WaterQualityElevationDistance to Service AreaProtected WatershedOnsite sanitation

SELECTION OF A WATER

SOURCE


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Spring form from a hightable in a cavernouslimestone.

Fault barrier can cause

pressurized water inconfined aquifer

Springs form where aperched water intersects theground surface

SPRING FORMATION


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STANDARDTYPEOFSPRINGS:

TYPE A Spring located on a downhill slope

TYPEB Spring gushing outona levelground

TYPEC Spring located inside a cavernoverhanging rock

TYPED Scattered springswhichrequiresa large intake

TYPEE Spring located belowan overhanging rock


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TYPE A INTAKE STRUCTURE:

PLAN

Adaptable where the spring is located on a downhill slope

SECTION A-A


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PLAN

Adaptable where the spring is gushing out on a level ground

SECTION A-A

TYPE B INTAKE STRUCTURE:


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TYPE C INTAKE STRUCTURE:

PLAN SECTION A-A

Adaptable where the spring is located inside a cavern


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TYPE D INTAKE STRUCTURE:

Adaptable where the scattered springs requires large intake

PLAN SECTION A-A


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TYPE E INTAKE STRUCTURE:

PLAN SECTION A-A

Adaptable where the spring is located below an overhanging rock


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Site, depth, diameter and expected

yield from hydrogeological data Geophysical investigation

Test well drilling or aquifer pumpingtest

Water quality tests

Elevation and distance to servicearea

Environmental Sanitation

GROUNDWATER :(Dug Well, Bored Well, Shallow Well,Deep well)

Water sources15


SOURCE


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Influent and Effluent Streams

An Influent stream contributeswater to the water table

An Effluent stream gains waterfrom the water table


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TYPES OF GROUND WATER AQUIFER:(Unconfined or free and artesian or Confinedconditions.)

IMPERMEABLESTRATA

RECHARGEAREA

WATER TABLE

CONFINEDAQUIFER

UNCONFINEDAQUIFER

WATERTABLE

FREE FLOWINGWATER

PIEZOMETRIC SURFACE

ARTESION WELLNON-FLOWING

WATER TABLE WELL

GROUND SURFACE

CONFININGSTRATUM


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Unconfined AquiferA horizontal (static) water tablepenetrated by a well that is notbeing pumped. The water tableremains static until pumpingbegins.

The water table in a pumping well

is drawn down an amountdetermined by the rate of pumpingand the permeability of the aquifer.The development of a cone ofdepression created a hydraulicgradient, which cause water to

flow toward the well and enablecontinuous water production. Theamount of water the well yields perunit of time pumped depends uponthe aquifers hydrologic properties.


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Confined Aquifer:

The hydraulic head in thehose lowers as water flows

out the low end. Eventually astatic condition prevails

A confined aquifer (commonlycalled an artesian aquifer. Thepotentiometric surface is thelevel to which water will rise in awell at specific points along theaquifer.

Sp ec ial c a se : Arte sian

a q uife r wa ter flow s fre e ly

w / o a id o f pum p


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BasicMethodsof WellDrilling


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5 Basic Methods of WellConstruction Hand Dug

Bored Well

Driven Well Jetted Well

Percussion or Rotary


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BOREHOLE

(Percussion or Rotary)

PERCUSSION RIG


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ROTARY RIG


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Water Source DevelopmentWell Classification

Dug Well (circular or rectangular in shape withdiameter ranging from 1 to 1.5 meters)

Shallow well (depth is less than () 20 meters.E.g. Malawi type, Magsaysay type, Afridevtype)


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TYPICAL WELL

SHALLOW WELL(LESS THAN 20M)

DEEP WELL(LESS THAN 60M)


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Well Development: These are procedures designed to maximize well yield.

Done thru overpumping, backwashing, mechanical surgingand jetting.

Why well development

Reduce compaction and intermixing of

grain sizes by removing fine materials

from pore spaces.

Remove drilling fluid coating the

borehole

Stabilize the formation so well will yield sand free water

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Pumping Test Analysis:

Pumping Tests are used to determine the

Performance characteristics of a well

Hydraulic parameters of the aquifer

These tests should be done by an expert in order to predict

the safe yield of the well and long term effects.

A rough test for determining safe yield is to pump the well at aminimum of 1.3 design requirement until the PWL stabilizes (min24 hrs test pumping). Safe yield can be taken at 70% of

stabilized pumping rate.

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Well Discharge Exercise:

Q = 0.001739 (d2

) xy 1/2

Where: d = pipe diameter in mm

x = carry distance in meters

y = drop in meters

Q = lps

Find the flow in a 62.7mm (2 inch) pipe flowing full where thedrop is 0.50 m (y axis) and the carry is 0.824 meters (x axis).

Solution: Q = 0.001739 x (62.7)2 x 0.824 = 7.9 lps0.501/2

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hydrologic study to confirm

water availability water quality tests

watershed characteristics

flood flows

river bed material & thickness of

pervious strata relative location and elevation to

the service area

water rights

SURFACE WATER (Weir and Diversion works,infiltration well or gallery, intakebox)

Water sources


SOURCE

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Float Method Procedure:

Measure float velocity @ 5x (the 2 pts should be 2-3 channels

apart) Use a float that sinks at least halfway the depth

Measure the distance between the 2 points and use a timer toget the average time.

V=m/sec

Determine channel cross section area between the 2 pts Q=0.85 AV

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PROTECT EXISTING SOURCE

RAIN WATER

CATCHMENT

DRIVENWELL

PROTECTED

SPRING

BORED

WELL

J ETTEDWELL

DUG WELL

DRILLEDWELL

DUG WELL

FROM SMALL WATER SUPPLIES THE ROSS INSTITUTE

YES

YES

NO

YES

NO

NO

YES

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

ARE RAINFALL PATTERN AND ROOF

DESIGN SUITABLE FOR RAIN WATER

CATCHMENT

IS WATER TABLE WITHIN 25 M.


IS GROUND WATER DRINKABLE

NO

NO

YES

CAN PEOPLE AFFORD THE STORAGE

TANKS NECESSARY FOR RAIN

WATER CATCHMENT

ARE PERENNIAL SPRINGS AVAILABLE

IS THE GROUND SOFT

IS THE GROUND SOFT

NO

NO

DOES IT YIELD ENOUGH

WATER

ARE WELL POINTS AVAILABLE

YES

YESDOES THE SOURCE Y IELD ENOUGH

WATERIS THERE AN EXISTING SOURCE

NO

YES

NO

YES

NO

YES

NOYES


ARE WATER AND J ETTING

EQUIPTMENTS AVAILABLEIS THE GROUND SOFT

IS EXPERTISE FOR HAND DUG WELLSAVAILABLE

CAN EXPERTS F IND A SUITABLELOCATION

YESYES

YESARE PERENINIAL SURFACE

WATER SOURCES AVAILABLE

IS EXPERTISE AND EQUIPTMENT FORDRILLING AVAILABLE

CAN DRILLERS FIND ASUITABLE LOCATION

05_DILG_Salintubig - Source Development

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