N.J. Admin. Code § 7:10-11.15

Current through Register Vol. 56, No. 12, June 17, 2024

Section 7:10-11.15 - Miscellaneous treatment processes

(a) Regulations for aeration are as follows:

1. The supplier of water shall evaluate each aeration treatment unit for its effectiveness in water treatment and adequate protection of the water.

2. Because of the large variation in aeration treatment unit's effective air to water ratios, the Department does not set minimum standards for the air to water ratio. The Department shall review and approve the design of each such treatment unit during its review of a permit application under this subchapter.

3. Any aeration process not subject to filtration for particulate removal must meet the following minimum requirements for protection against dust, insects, and bacteriological contamination:

i. All air entering an induced or forced air aeration unit shall be passed through a corrosion-resistant screen of not less than 24 mesh.

ii. All aerators, except those followed by flocculation, sedimentation and filtration units, shall be constructed so as to prevent contamination by birds, insects, wind-borne debris, rainfall and water draining off the exterior of the aerator.

iii. All forced air aeration units shall be equipped with air filters, including a filter to remove entrained oil when applicable.

(b) Regulations for water softening are as follows:

1. A public community water supply shall not be softened to zero hardness. Where water is softened, it shall be blended with unsoftened water to ensure that the delivered water contains a minimum hardness of 50 mg/l as calcium carbonate (CaCO[3]) prior to distribution.

2. Where carbon dioxide is used for recarbonation, the minimum detention time shall be 20 minutes. For lime softening, a shorter detention time may be utilized.

3. A rapid filter unit shall be used following any lime softening treatment unit.

4. For ion-exchange softening, the following requirements apply:

i. The ion-exchange process shall not be used to remove iron and manganese.

ii. Pretreatment is required for an ion-exchange process if the iron content of the water exceeds 0.3 mg/l and/or the manganese content exceeds 0.05 mg/l.

iii. The design criteria for ion-exchange softening treatment units are as follows:

(1) The maximum operating exchange capacity shall be 20 to 35 kilogram per cubic foot.

(2) The minimum resin bed depth shall be 36 inches.

(3) The softening flow rate shall be two to six gallons per minute per cubic foot.

(4) The backwash flow rate shall be five to six gallons per minute per cubic foot.

(5) The salt application rate shall be five to 20 pounds per cubic foot.

(6) The brine concentration shall be eight to 16 percent.

(7) The regeneration brine contact time shall be 25 to 45 minutes.

(8) The rinse water flow rate shall be one to five gallons per minute per cubic foot.

(9) The rinse water volume requirement shall be 20 to 40 gallons per cubic foot.

iv. Household-type units in parallel are prohibited.

v. Acceptable hardness levels may be achieved by blending softened and unsoftened water.

vi. Alternate methods of hardness removal shall be used if dissolved solids and/or sodium concentrations in the finished water exceed the limits established in the State secondary drinking water regulations at 7:10-7.2.

vii. Sequestration, as a substitute for hardness removal, shall not be used where raw water hardness levels exceed 300 mg/l.

(c) Regulations for the removal of iron and manganese are as follows:

1. All raw water in which iron levels exceed 0.6 mg/l and/or manganese levels exceed 0.1 mg/l shall be treated to remove the iron and/or manganese in excess of the limits in the State secondary drinking water regulations at N.J.A.C. 7:10-7.2.

2. Ground water in which iron and/or manganese levels exceed the limits in the State secondary drinking water regulations but do not exceed the limits specified in (c)1 above may be treated using a sequestering agent.

3. Pressure filtration rates for iron and/or manganese removal shall not exceed three gallons per minute per square foot.

(d) Regulations for corrosion control are as follows:

1. Corrosion control treatment shall be employed when the water is corrosive to the distribution system or plumbing.

2. When the hardness of the water is less than 50 mg/l as CaCO[3], neither caustic soda (sodium hydroxide) nor soda ash (sodium carbonate) alone shall be used to control corrosion unless used in conjunction with a corrosion inhibitor.

3. For smaller installations (less than 100 gallons per minute), calcite filters may be used for corrosion control.

4. Corrosion-inhibiting compounds designed to provide a protective film on the walls of distribution mains shall not be used unless approved by the Department. The approval will be based on either pilot plant or water system operational data on the use of the compound submitted by the public community water system.

5. Cathodic protection shall not be used for internal corrosion control in water mains.

(e) Regulations for taste and odor control are as follows:

1. Corrective treatment shall be employed to control objectionable tastes and odors in all waters.

2. Aeration, chlorine, chlorine dioxide, copper sulfate, ozone, potassium permanganate, granular activated carbon and powder activated carbon are acceptable for taste and odor control treatment.

3. If copper sulfate or other copper compounds are used to treat water, the residual copper levels in the distribution system shall not exceed 1.3 mg/l.

(f) Regulations for fluoridation are as follows:

1. Fluoridation treatment units shall be capable of maintaining a finished water fluoride level between 0.8 and 1.2 mg/l at all points in the distribution system.

2. The following compounds may be used for fluoridation:

i. Sodium fluoride;

ii. Sodium fluorosilicate; or

iii. Fluorosilicic acid.

3. Fluoridation chemicals shall be stored in their original unopened containers unless transferred to corrosion resistant covered storage containers.

4. Fluoridation feed equipment shall comply with applicable provisions of 7:10-11.12 and with the following:

i. Solution feed equipment may be used to feed solutions of sodium fluoride or fluorosilicic acid. Use of sodium fluorosilicate slurries is prohibited.

ii. Dry feed equipment may be of volumetric or gravimetric type. Gravimetric feeders shall be mounted on appropriately designed weighing scales. The dilution ratio for the fluoride solution shall be at least 12 gallons of water per pound of sodium fluoride or 60 gallons of water per pound of sodium fluorosilicate.

(1) A detention period of at least five minutes is required for sodium fluoride solution and 15 minutes for sodium fluorosilicate solution.

(2) The solution shall not be directly introduced into any pipe or conduit under negative pressure, and an antisiphon device shall be installed to prevent siphonage of the solution.

iii. Floor surfaces adjacent to feeders shall have a smooth and impervious finish, and shall be sloped to adequate drains to permit hosing of the floor with water.

iv. Waste liquids or sludge from fluoride solution tanks shall be disposed of in accordance with applicable State and Federal law and regulations. Appropriately designed dust control units shall be used in handling dry chemicals. Exhaust air from vacuum conveying equipment shall be filtered and discharged outdoors. Where chemical containers are manually emptied into the treatment unit, an exhaust fan with filter and suitable duct work to provide an air velocity of at least 200 feet per minute at the opening through which the chemical is being emptied shall be used. Such an exhaust fan is not required where containers are emptied in enclosures or through dust-tight connections. Crystalline or granular forms of the chemical may be used to reduce dust.

v. Vapor shall be vented to the outdoors when fluorosilicic acid is handled. The acid shall not be handled in open vessels but shall be pumped through a closed system with an air inlet from the outside.

vi. Equipment for use and handling of fluoridation compounds shall include the provision of rubber or neoprene gloves and, where dry fluoride chemicals are handled, U.S. Bureau of Mines approved dust respirators. Hand washing facilities shall be available.

vii. Fluoridation storage and feed equipment shall be in rooms separate from other treatment units. Rooms in which fluoridation compounds are stored and/or handled shall be secured against the entry of unauthorized persons.

viii. A fluoride residual test kit shall be furnished for the routine testing of water samples for fluoride content.

(g) Regulations for packed column aeration for the removal of volatile organic compounds (VOCs) are as follows:

1. The packed column shall be designed to remove VOCs from at least twice the maximum level found in the system water source to below the MCL established in the State primary drinking water regulations at N.J.A.C. 7:10-5. The removal efficiency should not be less than 95 percent.

2. The packed column flooding condition of the packing material shall be avoided. The specific conditions under which hydraulic flooding shall occur, and the means by which such flooding shall be avoided, shall be specified in the engineer's report submitted with the application for a permit under this subchapter.

3. Scaling of the packing within a packed column shall be avoided. An evaluation of the impact of air stripping carbon dioxide and other gases in the water on water quality shall be provided in the engineer's report submitted with the application for a permit under this subchapter. The evaluation shall describe the effect that aeration of hard waters may have on scaling of the packing.

4. Vapor phase treatment of the air effluent shall be provided when required to meet air quality standards pursuant to the Air Pollution Control Act, 26:2C-1 et seq. and N.J.A.C. 7:27.

5. Packing support trays shall be provided.

6. Wall wipers or redistributors are required at a minimum of 10 foot column intervals in order to prevent short-circuiting.

7. The column shall be constructed to facilitate a change in height of the packing and replacement of the packing without major reconstruction.

8. Means shall be provided to drain the column riser pipe.

9. Pre- and post-column water sampling taps are required. Means to facilitate measurement of influent and effluent air quality and intake air quantity shall be provided.

10. The packed column shall be designed to facilitate the periodic adding of chlorine for pre-disinfection or of another oxidant or acid for cleaning the medium.

11. The air intake shall be located so as to avoid recirculation of the gas phase discharge from the top of the facility.

12. Protective screens of a minimum 24 mesh and air particulate filters are required on the air intakes.

13. A moisture barrier (demister) shall be provided.

14. Backup blowers are required where multiple water sources are being treated.

(h) Regulations for granular activated carbon (GAC) for adsorption of organic compounds are as follows:

1. The requirements for filtration at 7:10-11.14 shall be met, as applicable.

2. The empty bed contact time shall not be less than 20 minutes.

3. The GAC treatments units shall be capable of being backwashed, even if the GAC is not used as a filtration medium. The minimum available backwash rate shall be 12 gallons per minute per square foot of medium surface area.

4. If GAC is used as a dual function medium (filter and adsorber), the estimated time of breakthrough shall be redetermined to account for the chromatographic effect of frequent backwashing.

5. For GAC contained in pressure vessels, means for releasing excess pressure shall be provided to prevent over pressurization.

6. The influent and effluent lines to the GAC treatment unit shall be equipped with samplings taps. In addition, at least two taps shall be spaced in a vertical line within the GAC bed for monitoring the progress of the mass transfer zone within the GAC treatment unit.

7. Since GAC is easily abraded, transport systems shall be designed to minimize GAC breakup.

8. Virgin GAC shall be used, except that regenerated GAC may be used if such GAC was used previously only in potable water treatment plants and regenerated in facilities used only for potable water treatment plant filter media.

9. The GAC bed shall be a minimum of 48 inches deep.

10. GAC shall not be used as a dual functioning medium (filter and adsorber) when synthetic organic chemicals are regularly present in the raw water and filtration of the water is required.

11. GAC treatment units must be pilot or bench tested to determine GAC life.

12. Each GAC treatment unit shall be provided with isolation valves and a drain.

N.J. Admin. Code § 7:10-11.15

Amended by R.2000 d.354, effective 8/21/2000.
See: 31 N.J.R. 2717(b), 32 N.J.R. 3106(a).
In (f)4ii, substituted "Gravimetric" for "Volumetric" in the second sentence.