Environmental Health & Safety Compliance Blog

Meeting metal limits in wastewater discharge permits

Posted by Rebecca McDaniel on Mar 23, 2010 7:36:00 AM

 The importance of proper sample collection.

By Sandy Perry, Director of Water Management and Wastewater Services

Whether you discharge to the sewer or directly to a water body, the importance of collecting truly representative samples of your treated wastewater cannot be overstated. So what does "representative" mean? It means that:

  1. your wastewater treatment system is operating properly,
  2. you've selected a day to sample that is typical of your daily operations,
  3. your composite sampling equipment is set up to take flow proportioned samples properly,
  4. your flow meter is sized appropriately for your flow rates and is calibrated at least annually, and finally,
  5. the sampling equipment and collection containers are clean!!

To my last point, the last thing you want is a cross-contaminated sample. If you think about it, there are actually quite a few opportunities for contamination. And with metals limits in parts per billion, it doesn't take much to tip the lab results over the limit.

Dischargers should check with their sampling contractor regarding their procedures to prevent sample contamination. Do they change the pump tubing or just rinse it out between yours and another client's sampling? Do they acid wash and rinse the collection container? And how does he or she appear when they are onsite to setup and collect the samples - is their appearance neat and clothing clean? Even dirty hands and dust/dirt on clothing can be a potential source of contamination.

Did you know that in some areas of the country, dischargers are subject to limits in parts per trillion (Maine and the Great Lake areas' mercury limits are in ug/L) and must perform "clean sampling"? The U.S. EPA's Clean Sampling guidance includes using non-metal sampling equipment, and wearing tyvek suits and gloves, and even warns against breathing near the sample (ex. mercury in dental fillings).

You might also check with your contractor to find out if they perform periodic equipment or field blanks as part of their Quality Control program? Do they have a Quality Control Program? Non-compliance is not a pleasant situation to be in and can lead to enforcement actions including fines and penalties. Don't take a chance, make sure that your samples are being collected properly to ensure that your data is "representative" of your discharge.

Tags: EPA, Compliance, Wastewater

Information gap…MWRA versus MassDEP…beware wastewater dischargers

Posted by Rebecca McDaniel on Mar 18, 2010 2:50:00 PM

By Sandy Perry, Director of Water Management and Wastewater Services

How do companies in Massachusetts know which regulations apply to their wastewater sewer discharge? It's interesting how much separation there is between a local authority, such as the Massachusetts Water Resource Authority, and the state authority, the MassDEP. Unfortunately the lack of outreach by either entity typically results in something being missed with respect to compliance.

In fact, no matter which sewer authority a facility in Massachusetts discharges to, wastewater treatment system plans and descriptions must be submitted to the MassDEP along with a staffing plan. Also, facilities are required to have an Operations & Maintenance Manual specific to their system. And depending on the volume discharged, you may need a MassDEP permit as well.

On the other hand, the MWRA (and most local authorities) are most concerned about the characteristics of the wastewater being discharged. They care only that it meets compliance with the sewer use ordinance, local limits, and/or specific permit limits. That is because they have a biological treatment system to protect and their own discharge limits to meet. In most instances you will be required to apply for a discharge permit. However, some of the smaller communities and sewer authorities may not require a permit if your discharge volume is low or you have no chemicals of concern in use.

So my best advice is to do your due diligence before starting up or relocating. Companies need to look into their regulatory obligations prior to moving and understand just what is required. And those already in operation, to be on the safe side, check to make sure that you have made the proper submittals to the MassDEP and/or local sewer authority. (A final word of caution - don't assume that the contractor that installed your treatment system took care of this for you.)

Tags: Wastewater Treatment, Wastewater