Draft chapter 97: Use of Public Sewers

§ 97.04 Restricted Discharges

The 2026 draft's § 97.04 beside the current code's § 97.04: removed words are struck through, added words underlined.

Comparison with a draft: not adopted. The archive holds no public hearing, ordinance or vote adopting the recodified Code through the October 20, 2026 meeting packet. Until one is adopted, every page here compares the consolidated code with a draft that can still change: the revised draft with the October 6 changes is not in the archive.

A comparison with the August 2026 draft recodification prepared by Iowa Codification for the City. The draft has not been adopted and can still change; the current code (unofficial compilation) governs until a recodified Code is adopted. Matches between sections are made by machine from the texts and are reviewed where uncertain.

Wording changed minor wording (98% same words)

What changed

. No person shall discharge or cause to be discharged the following described substances, materials, waters, or wastes if it appears likely in the opinion of the Superintendent that such wastes can harm either the sewers, sewage treatment process, or equipment, have an adverse effect on the receiving stream or can otherwise endanger life, limb, public property, or constitute a nuisance. In forming an opinion as to the acceptability of these wastes, the Superintendent will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment process, capacity of the sewage treatment plant, degree of treatability of wastes in the sewage treatment plant, and other pertinent factors. The substances restricted are:
1. High Temperature. Any liquid or vapor having a temperature higher than one hundred fifty degrees (150º) F (65º C). 150℉ (65℃).
2. Fat, Oil, Grease. Any water or waste containing fats, wax, grease, or oils, whether emulsified or not, in excess of 100 milligrams per liter or 600 milligrams per liter of dispersed or other soluble matter.
3. Viscous Substances. Water or wastes containing substances which that may solidify or become viscous at temperatures between 32º F 32℉ and 150º F (0º 150℉ (0℃ to 65º C). 65℃).
4. Garbage. Any garbage that has not been properly shredded, that is, to such a degree that all particles will be carried freely under the flow conditions normally prevailing in public sewers, with no particle greater than one-half (½) inch in any dimension.
5. Acids. Any waters or wastes containing strong acid iron pickling wastes, or concentrated plating solution solution, whether neutralized or not.
6. Toxic or Objectionable Wastes. Any waters or wastes containing iron, chromium, copper, zinc, and similar objectionable or toxic substances; or wastes exerting an excessive chlorine requirement, to such degree that any such material received in the composite sewage at the sewage treatment works exceeds the limits established by the Superintendent for such materials.
7. Odor or Taste. Any waters or wastes containing phenols or other taste or odor producing substances, in such concentrations exceeding limits which that may be established by the Superintendent as necessary, after treatment of the composite sewage, to meet the requirements of state, State, federal, or other public agencies of jurisdiction for such discharge to the receiving waters.
8. Radioactive Wastes. Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the Superintendent in compliance with applicable State or Federal federal regulations.
9. Excess Alkalinity. Any waters or wastes having a pH in excess of 9.5.
10. Unusual Wastes. Materials which that exert or cause:
A. Unusual concentrations of inert suspended solids (such as, but not limited to, Fullers earth, lime slurries, and lime residues) or of dissolved solids (such as, but not limited to, sodium chloride and sodium sulfate).
B. Excessive discoloration (such as, but not limited to to, dye wastes and vegetable tanning solutions).
C. Unusual B.O.D., chemical oxygen demand, or chlorine requirements in such quantities as to constitute a significant load on the sewage treatment works.
D. Unusual volume of flow or concentration of wastes constituting “slugs” as defined herein.
11. Noxious or Malodorous Gases. Any noxious or malodorous gas or other substance which that, either singly or by interaction with other wastes wastes, is capable of creating a public nuisance or hazard to life or of preventing entry into sewers for their maintenance and repair.
12. Damaging Substances. Any waters, wastes, materials materials, or substances which that react with water or wastes in the sewer system to release noxious gases, develop color of undesirable intensity, form suspended solids in objectionable concentration concentration, or create any other condition deleterious to structures and treatment processes.
13. Untreatable Wastes. Waters or wastes containing substances which that are not amenable to treatment or reduction by the sewage treatment processes employed, or are amenable to treatment only to such degree that the sewage treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharge to the receiving waters.

Word-level comparison of the current text with the draft's; spacing and paragraph breaks come from the documents' text. Footnotes are left out.

Current code

§ 97.04 Restricted Discharges

No person shall discharge or cause to be discharged the following described substances, materials, waters, or wastes if it appears likely in the opinion of the Superintendent that such wastes can harm either the sewers, sewage treatment process, or equipment, have an adverse effect on the receiving stream or can otherwise endanger life, limb, public property, or constitute a nuisance. In forming an opinion as to the acceptability of these wastes, the Superintendent will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment process, capacity of the sewage treatment plant, degree of treatability of wastes in the sewage treatment plant, and other pertinent factors. The substances restricted are:

1. High Temperature. Any liquid or vapor having a temperature higher than one hundred fifty degrees (150º) F (65º C).

2. Fat, Oil, Grease. Any water or waste containing fats, wax, grease, or oils, whether emulsified or not, in excess of 100 milligrams per liter or 600 milligrams per liter of dispersed or other soluble matter.

3. Viscous Substances. Water or wastes containing substances which may solidify or become viscous at temperatures between 32º F and 150º F (0º to 65º C).

4. Garbage. Any garbage that has not been properly shredded, that is, to such a degree that all particles will be carried freely under the flow conditions normally prevailing in public sewers, with no particle greater than one-half (½) inch in any dimension.

5. Acids. Any waters or wastes containing strong acid iron pickling wastes, or concentrated plating solution whether neutralized or not.

6. Toxic or Objectionable Wastes. Any waters or wastes containing iron, chromium, copper, zinc, and similar objectionable or toxic substances; or wastes exerting an excessive chlorine requirement, to such degree that any such material received in the composite sewage at the sewage treatment works exceeds the limits established by the Superintendent for such materials.

7. Odor or Taste. Any waters or wastes containing phenols or other taste or odor producing substances, in such concentrations exceeding limits which may be established by the Superintendent as necessary, after treatment of the composite sewage, to meet the requirements of state, federal, or other public agencies of jurisdiction for such discharge to the receiving waters.

8. Radioactive Wastes. Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the Superintendent in compliance with applicable State or Federal regulations.

9. Excess Alkalinity. Any waters or wastes having a pH in excess of 9.5.

10. Unusual Wastes. Materials which exert or cause:

A. Unusual concentrations of inert suspended solids (such as, but not limited to, Fullers earth, lime slurries, and lime residues) or of dissolved solids (such as, but not limited to, sodium chloride and sodium sulfate).

B. Excessive discoloration (such as, but not limited to dye wastes and vegetable tanning solutions).

C. Unusual B.O.D., chemical oxygen demand, or chlorine requirements in such quantities as to constitute a significant load on the sewage treatment works.

D. Unusual volume of flow or concentration of wastes constituting “slugs” as defined herein.

11. Noxious or Malodorous Gases. Any noxious or malodorous gas or other substance which either singly or by interaction with other wastes is capable of creating a public nuisance or hazard to life or of preventing entry into sewers for their maintenance and repair.

12. Damaging Substances. Any waters, wastes, materials or substances which react with water or wastes in the sewer system to release noxious gases, develop color of undesirable intensity, form suspended solids in objectionable concentration or create any other condition deleterious to structures and treatment processes.

13. Untreatable Wastes. Waters or wastes containing substances which are not amenable to treatment or reduction by the sewage treatment processes employed, or are amenable to treatment only to such degree that the sewage treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharge to the receiving waters.

2010 Code, Chapter 97 · source page

2026 draft

§ 97.04 Restricted Discharges

. No person shall discharge or cause to be discharged the following described substances, materials, waters, or wastes if it appears likely in the opinion of the Superintendent that such wastes can harm either the sewers, sewage treatment process, or equipment, have an adverse effect on the receiving stream or can otherwise endanger life, limb, public property, or constitute a nuisance. In forming an opinion as to the acceptability of these wastes, the Superintendent will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment process, capacity of the sewage treatment plant, degree of treatability of wastes in the sewage treatment plant, and other pertinent factors. The substances restricted are:

1. High Temperature. Any liquid or vapor having a temperature higher than 150℉ (65℃).

2. Fat, Oil, Grease. Any water or waste containing fats, wax, grease, or oils, whether emulsified or not, in excess of 100 milligrams per liter or 600 milligrams per liter of dispersed or other soluble matter.

3. Viscous Substances. Water or wastes containing substances that may solidify or become viscous at temperatures between 32℉ and 150℉ (0℃ to 65℃).

4. Garbage. Any garbage that has not been properly shredded, that is, to such a degree that all particles will be carried freely under the flow conditions normally prevailing in public sewers, with no particle greater than one-half inch in any dimension.

5. Acids. Any waters or wastes containing strong acid iron pickling wastes, or concentrated plating solution, whether neutralized or not.

6. Toxic or Objectionable Wastes. Any waters or wastes containing iron, chromium, copper, zinc, and similar objectionable or toxic substances; or wastes exerting an excessive chlorine requirement, to such degree that any such material received in the composite sewage at the sewage treatment works exceeds the limits established by the Superintendent for such materials.

7. Odor or Taste. Any waters or wastes containing phenols or other taste or odor producing substances, in such concentrations exceeding limits that may be established by the Superintendent as necessary, after treatment of the composite sewage, to meet the requirements of State, federal, or other public agencies of jurisdiction for such discharge to the receiving waters.

8. Radioactive Wastes. Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the Superintendent in compliance with applicable State or federal regulations.

9. Excess Alkalinity. Any waters or wastes having a pH in excess of 9.5.

10. Unusual Wastes. Materials that exert or cause:

A. Unusual concentrations of inert suspended solids (such as, but not limited to, Fullers earth, lime slurries, and lime residues) or of dissolved solids (such as, but not limited to, sodium chloride and sodium sulfate).

B. Excessive discoloration (such as, but not limited to, dye wastes and vegetable tanning solutions).

C. Unusual B.O.D., chemical oxygen demand, or chlorine requirements in such quantities as to constitute a significant load on the sewage treatment works.

D. Unusual volume of flow or concentration of wastes constituting “slugs” as defined herein.

11. Noxious or Malodorous Gases. Any noxious or malodorous gas or other substance that, either singly or by interaction with other wastes, is capable of creating a public nuisance or hazard to life or of preventing entry into sewers for their maintenance and repair.

12. Damaging Substances. Any waters, wastes, materials, or substances that react with water or wastes in the sewer system to release noxious gases, develop color of undesirable intensity, form suspended solids in objectionable concentration, or create any other condition deleterious to structures and treatment processes.

13. Untreatable Wastes. Waters or wastes containing substances that are not amenable to treatment or reduction by the sewage treatment processes employed, or are amenable to treatment only to such degree that the sewage treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharge to the receiving waters.

August 2026 draft · page 206

Back to draft chapter 97 · All changes

Data last updated October 22, 2026. Built from the archive's documents; see how the data is built.