Figure: 30 TAC §285.91(11)

TABLE XI

INTERMITTENT SAND FILTER MEDIA SPECIFICATIONS

(ASTM C-33)

Particle Size Distribution
Sieve	Particle Size	Percent Passing
3/8 inch	9.50 mm	100
No. 4	4.75 mm	95 to 100
No. 8	2.36 mm	80 to 100
No. 16	1.18 mm	50 to 85
No. 30	0.60 mm	25 to 60
No. 50	0.30 mm	10 to 30
No. 100	0.15 mm	2 to 10
No. 200	0.075 mm	3

1. The sand shall have not more than 45% passing any one sieve and retained on the next consecutive sieve listed in TABLE XI.
2. The limit for material that can pass the No. 200 sieve shall not be more than 3%.
3. The fineness modulus shall not be less than 2.3 nor more than 3.1, and is defined as a numeric quantity to control the distribution of filter media particle sizes within the specified range for intermittent sand filters. The finess modulus is calculated by adding the cumulative percents of samples retained on the following screens, dividing the sum by 100.

U.S. Bureau of Standards

Sieve		Particle Size
3/8 inch		9 .50 mm
No. 4		4 .75 mm
No. 8		2 .36 mm
No. 16		1.18 mm
No. 30		0.60 mm
No. 50		0 .30 mm
No. 100		0.15 mm

	1.	The sand shall have not more than 45% passing any one sieve and retained on the next consecutive sieve listed in TABLE XI.
	2.	The limit for material that can pass the No. 200 sieve shall not be more than 3%.
	3.	The fineness modulus shall not be less than 2.3 nor more than 3.1, and is defined as a numeric quantity to control the distribution of filter media particle sizes within the specified range for intermittent sand filters. The finess modulus is calculated by adding the cumulative percents of samples retained on the following screens, dividing the sum by 100.