Frequently Asked Questions
Our office has recorded these “sewer smell” issues being correlated to at least two common events.
The first event is can be associated with the replacement of a hot water heater. The sewer smell, which is reduced sulfur, is a by-product of bacteria that were present within the water heater before the water heater’s commissioning. The destruction of those bacteria can be achieved through conformance with the disinfection procedures outlined within the Uniform Plumbing Code’s Chapter 6.
The second event occurs from the by-product of bacteria in the p-trap. The p-trap develops a biofilm over time. That biofilm provides a food source and medium of growth for the bacteria. Unless the biofilm is removed, either chemically or mechanically, the reduced sulfur smell will exit up through the p-trap whenever the water in the p-trap is disturbed. This correlation typically leads the observer to assume the smell is coming from the water exiting a faucet rather than from the water collected in the p-trap.
Either of these events may be occurring in an apartment where a sewer (rotten egg/sulfur smell) is present. Due to the isolated nature of these events, management offices will not likely receive complaints from other tenants. This is because the isolated events arise from the activities in the water system or sewer system of the effected apartment. This would not be a complex wide issue or a water main issue.
If you are looking into the installation of a reverse osmosis system. you may have deduced by now, the reduced sulfur smell is an issue which can be fixed/remedied with basic maintenance practices. Using a reverse osmosis system will not fix the source of this issue; it will merely mask the issue and require a commitment to replacing reverse osmosis system filters. Additionally, reverse osmosis systems are resource intensive and require on average 10 gallons of water to produce 1 gallon of final reverse osmosis filtered water. Depending upon use, this may increase a water bill, further adding to the operational cost commitment.
Overall, our office recommends your management office addresses the two types of events we have outlined to remedy this issue: follow the Uniform Plumbing Codes Chapter 6 to disinfect the hot water heater and the hot water pipes that lead from the water heater; and, clean out the p-traps in the effected apartment. We hope you have found this information informative, and you are always welcome to contact us with any questions. We are also interested in determining if these solutions correct this reduced sulfur issue, and look forward to hearing from you about the final results.
Our office does not recommend residents or visitors drink, consume or cook ground water with nitrate concentrations which exceed the Maximum Contaminant Level (MCL) of 10 milligrams per liter (mg/L) of nitrate. This MCL is based upon research carried out by the Environmental Protection Agency (US EPA).
Infants below the age of six months who drink water containing nitrate and/or nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome. These risks also affect nursing mothers and unborn infants. To address this issue, our office recommends the well owner and other users of the contaminated water well establish a contingency plan that includes, at minimum, the following items:
- A procedure to collect a confirmation water sample for nitrate within 24 hours of receiving the analytical results, of the original sample, from the laboratory.
- Preparation of a Do Not Drink Notice to all parcels serviced by the contaminated water well.
- Corrective action plan: In the event that the nitrate level continues to exceed the MCL, a corrective action plan will aid the well owner in outlining their approach. The plan should address the following:
- Acquisition of another suitable supply of water;
- Treatment of the source water under the supervision of a Clark County contractor or plumber familiar with Chapter 6 of the Uniform Plumbing Code and National Sanitation Foundation private domestic treatment plant standards;
- Consolidation with an adjacent public water system that provides water of sufficient quantity and quality; or
- Any other actions sufficient to return bring nitrate concentrations below 10 mg/L.
Recommendation 3b may be addressed using either reverse osmosis, electrodialysis/ED Reversal, or anion exchange treatment. These treatment methods are recognized by the American Water Works Association as generally effective treatment processes for nitrate. In rare cases, depending upon initial nitrate concentrations, more than one treatment unit may be needed in series to achieve a reliable and consistent below 10 mg/L nitrate concentration. It is ultimately the responsibility of the well owner and each individual parcel owner to:
- pilot these treatment options and determine if nitrate will be effectively treated below 10 mg/L, and
- to maintain treatment media for the duration of time the contaminated water well source is used to provide water for drinking and culinary purposes.
Our office understands these treatment options are expensive. In most cases, it is only necessary to treat water that is destined for consumption and culinary purposes. Therefore, a cost-effective method of treatment would be to install a point-of-use nitrate treatment unit within the parcel owner’s home, and all other homes which draw water from the referenced water well.
Updated on: March 1, 2019