§ 9-6-14. Excessive Discharge Prohibited.

The following described substances, materials, waters, or waste shall be limited in discharge to municipal systems to concentrations or quantities which will not harm either the sewers, wastewater treatment process, POTW personnel, or equipment, will not have an adverse effect on the receiving stream, or will not endanger lives, limbs, public property, or constitute a nuisance. The Director may set limitations lower than the limitations established in the regulations below if, in his opinion, such more severe limitations are necessary to meet the above objectives. In forming his opinion as to the acceptability, the Director will give consideration to such factors as to the quantity of subject waste in relation to flows and velocities in the sewers, materials of construction of the sewers, the wastewater treatment process employed, capacity of the wastewater treatment plant, degree of treatability of the waste in the wastewater treatment plant, and other pertinent factors. In no case, however, will a federally mandated prohibition be exempted or be altered to be less stringent. The limitations or restrictions on materials or characteristics of waste or wastewaters discharged to the sanitary sewer which shall not be violated without approval of the Director are as follows:

(a)

Wastewater sufficiently hot to cause the influent at the wastewater treatment facilities to exceed one hundred four (104) degrees Fahrenheit or forty (40) degrees Celsius.

(b)

Wastewater containing more than twenty-five (25) milligrams per liter of nonflammable petroleum oil, nonbiodegradable cutting oils, or products of mineral oil origin in amounts that will cause interference or pass through.

(c)

Any wastewaters containing fats, wax, grease, or oils, whether emulsified or not, in excess of one hundred (100) mg/l or containing substances which may solidify or become viscous at temperatures between thirty-two (32) degrees Fahrenheit and one hundred forty (140) degrees Fahrenheit (zero to sixty (60) degrees Celsius).

(d)

Any garbage that has not been properly shredded (see Section 9-6-1). Garbage grinders may be connected to sanitary sewers from homes, hotels, institutions, restaurants, hospitals, catering establishments, or similar places where garbage originates from the preparation of food in kitchens for the purpose of consumption on the premises or when served by caterers.

(e)

Any water or wastes containing heavy metals, solvents, and similar objectionable or toxic substances to such degree that any such material discharged to the public sewer exceeds the limits established by the Director, the NHDES, or the National Categorical Pretreatment Standards (40 C.F.R., Chapter I, Subchapter N, parts 405—471) for such materials.

(f)

Water or wastes containing substances or pollutants which shall pass through or interfere with operations or performance of the POTW or are not amenable to treatment or reduction by wastewater treatment processes employed to such degree that the wastewater treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharge to the receiving waters.

(g)

Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the Director in compliance with applicable state or federal regulations.

(h)

Quantities of flow, concentrations, or both which constitute a "slug" as defined herein.

(i)

Any water or wastes which, by interaction with other water or wastes in the public sewer system, release obnoxious gases, form suspended solids which interfere with the collection system, or create a condition deleterious to structures and treatment processes.

(j)

Any wastewaters containing an increase in caustic alkalinity, calculated as CaCo ₃ (calcium carbonate) in excess of seventy-five (75) parts per million by weight, or in volumes which may be excessive.

(k)

Any obnoxious or malodorous gas or substance capable of creating a public nuisance.

(l)

Any wastewaters containing:

(1)

An average concentration of suspended solids in excess of three hundred (300) milligrams per liter (mg/l).

(2)

Materials which cause excessive discoloration (such as, but not limited to, dye wastes and vegetable tanning solutions).

(3)

An average concentration of BOD in excess of two hundred fifty (250) milligrams per liter (mg/l) or material which causes unusual chemical oxygen demand.

(m)

Any water or waste containing any or all pollutants in such concentrations as to cause the receiving wastewater treatment facility to exceed its maximum allowable headworks loading(s) (MAHL) in pounds per day calculated for these pollutants with respect to the facility's current average monthly influent wastewater flow.

The pollutants of present concern and their projected allowable headworks loadings in pounds per day at maximum design flow in million gallons per day (mg/d) for each wastewater facility listed below:

Pollutant	Hall Street Wastewater Treatment Facility MAHL	(mg/l) Uniform Concentration Limit
Cadmium	0.225	0.12
Copper	18.33	12.00
Lead	4.06	2.71
Nickel	7.87	5.37
Silver	10.69	7.90
Zinc	14.05	6.07

 

The uniform concentration limits apply to all nondomestic wastes or wastewaters discharged to the Hall Street Wastewater Treatment Facility and will be in all significant industrial user (SIU) discharge permits. All concentrations listed above are for total metals.

The Director may impose mass limitations in addition to, or in place of, the concentration-based limits above.

(Ord. No. 2292, § II, 2-8-99; Ord. No. 2749, § VI, 4-13-09; Ord. No. 2758, § VI, 7-13-09)