Water containing a fixed amount of oxygen and a varying amount of carbonic acid acts upon lead with an energy proportional to the amount of carbonic acid present. The action of water upon a bright lead surface is much more energetic than upon a dull lead surface. Thus, city rain water, stored for 3 1/2 months in contact with new and old lead surfaces, was found to contain in suspension and solution the following amount of lead.

*Stored in old lead, 3.65 parts per million Stored in new lead, 58.10 parts per million

The importance of this will be realized when it is known that 0.5 part of lead per million is considered by most authorities the danger limit.

At Lowell, Mass., +the water from a well that caused a serious outbreak of lead poisoning was found, upon analysis, to be heavily charged with carbonic acid and to contain 2.30 parts of lead per million.

Hard waters generally protect lead pipe by depositing on the inner surface an insoluble coating. As a rule, the harder the water, as compared with the free carbonic acid, the less effect the water has upon the lead. Ground water is generally more energetic than surface water in its action upon lead, although surface water is more liable to become contaminated with sewage, in which case the resultant carbonic acid would make it more dangerous than ground water.

* Mason Water Supply, page 398.

+ Massachusetts State Board of Health Report, 1900, page 488.

An idea of the amount of lead dissolved from lead pipes by different kinds of water can be found in tables XVI, XVII, XVIII. In these tables the quantity of lead dissolved is stated in parts per 100,000, in which amounts .05 part of lead is considered the danger limit.

Table XVI - Lead Found In Drinking Water - List Of Cities And Towns With Maximum Amounts Of Lead Found In Samples Of Water Taken During Ordinary Use And After Standing In The Pipe

LOCALITY

Lead Parts per 100,000

(.05 parts or lead per

100,000, dangerous)

During

Ordinary

Use

After

Standing in Pipe

Amesbury .......

.0029

0.0043

Andover.......

.0171

0.0571

Attleborough.......

.1714

0.1371

Beverly.......

.0257

0.0314

Bridgewater......

.0086

0.0171

Brookline .......

.0114

0.0286

Cambridge......

.0086

0.0114

Cohasset......

.0086

0.0086

Dedham.......

.0100

0.0200

Franklin.......

.0286

0.1143

Grafton .......

.0229

0.0457

Hyde Park (old wells) ....

.0457

0.4571

Hyde Park (new wells) ....

.0200

0.0457

Lawrence .......

.0371

0.1829

Lowell (boulevard wells) ....

.0800

0.4000

Lowell (cook and hydraulic wells) .

.5143

0.4643

Marblehead ......

.0086

0.0143

Metropolitan supply.....

.0400

0.1371

Middleborough ......

.3429

1.1429

Needham.......

.0171

0.0429

Newton .......

.0714

0.1714

North Attleborough .....

.0071

0.0329

Norwood .......

.0043

0.1371

Webster .......

.0200

0.0571

Wellesley .......

.0152

0.0314

Weymouth ......

.0800

0.2286

Woburn .......

.0229

0.0343

(Report Massachusetts Board of Health, 1900, page 490.)

These tables all show the increased amount of lead dissolved from pipes by water that was standing for some time, and indicate the additional protection to health that can be obtained by allowing the water in the service pipe to run to waste before drawing any for cooking or drinking purposes.

Table XVII - Lead In Samples Of Ground Waters, Arranged According To Average Amount Of Lead Found When Water Is In Ordinary Use

(parts per 100,000-.05 part per 100,000, dangerous.)

LOCALITY

SAMPLES TAKEN

Lead

(Average)

Average Length of Pipe (Feet)

Average

Size of Pipe

(Inches)

Free

C. O 2

Hardness

Lowell (cook and hydraulic wells) .

In ordinary use ....

After standing in pipe . .

.1608

.2535

79

3/4

3 287

3 5

Middlesborough

.

In ordinary use ....

After standing in pipe . .

.1549

.6171

123

3/4

4.148

2 6

Attleborough

In ordinary use . . . .

After standing in pipe . .

.0697

.0905

95

3/4

3 242

1.7

Newton

In ordinary use ....

After standing in pipe . .

.0432

.0908

179

3/4

1.187

2.2

Hyde Park (old wells) .

In ordinary use ....

After standing in pipe . .

.0400

.3029

43

3/4

3.243

4.6

Lowell (boulevard wells)

In ordinary use ....

After standing in pipe . .

.0202

.086q

62

3/4

1.301

1.5

Grafton

In ordinary use ....

After standing in pipe . .

.0187

.0329

265

7/4

1.912

3 2

Hyde Park (new wells) . . . .

In ordinary use . . . .

After standing in pipe . .

.0172

.0329

32

3/4

2.733

2 9

Wellesley

In ordinary use ....

After standing in pipe . .

.0101

.0219

98

1/4

1.092

2.3

Webster

In ordinary use ....

After standing in pipe . .

.0100

.0286

76

3/4

1.689

0.8

Needham . . . .

In ordinary use ....

After standing in pipe . .

.0091

.0269

112

/

1/4

2.392

2.1

Dedham

In ordinary use ....

After standing in pipe . .

.0082

.0150

230

1/4

1.611

4. 1

Brookline

In ordinary use ....

After standing in pipe . .

.0074

.0197

461

3/4

1.149

4.7

Bridgewater

In ordinary use ....

After standing in pipe . .

.0057

.0143

127

3/4

1.084

2.6

North Attleborugh.

In ordinary use ....

After standing in pipe . .

.0049

.0226

144

3/4

1.529

2.9

Cohasset . . . . -

In ordinary use . . .

After standing in pipe . ".

.0048

.0043

39

1

2.411

6 3

(Report Massachusetts State Board of Health, 1900, page 491.)

* Chemical News X- X-'85.