The cost for the TCH course, meals and the harbor boat cruise is $800 per person.

The Deer Island tour is FREE.

You will earn up to 5 TCHs for this course. PAI will be conducting the workshops on board one of Boston Harbor Tours’ boats. Breakfast and lunch will be served on board. After the course is complete we will dock at Deer Island and take a tour of the grounds and treatment plant. The Deer Island tour will be run by MWRA staff, and is sponsored by WOOMA, the non-profit Wastewater Operators of Massachusetts Association.

The cost for the TCH course, meals and the harbor boat cruise is $800 per person.

The Deer Island tour is FREE. If you would like to attend ONLY the Deer Island tour, and not earn any TCHs, you are welcome to find transportation to the island and join our group for the tour.

Register today!

Boston, MA – Leading environmental firm Practical Applications, Inc. (PAI) has been awarded the contract to build the central wastewater treatment system for the plant expansion project at Tribe Foods, Inc., a subsidiary of Nestle, SA.

Tribe Foods Wastewater Treatment System - DAF Unit supplied by Krofta

Wastewater generated during food manufacturing operations is controlled using Dissolved Air Flotation. Designed to meet strict Massachusetts sewer discharge limits, wastewater in the system is continuously treated at 50,000 gallons per day with peak flows of 200 gallons per minute.

Composed of a 12,000 gallon equalization tank, pH Neutralization controls, coagulant and polymer dosing, rotary drum screening, and sludge dewatering, the system incorporates PAI’s automatic control package and integrated expert knowledge software to predict and prevent system upset. The system is housed in a custom-built 400 square foot packaged steel building.

PAI has been designing, building, and operating wastewater treatment systems since 1994. Our systems are designed and built by operating engineers and technicians who understand that an effective system must ensure performance while remaining economical to operate and maintain.

We wanted to send out a notification for those who did not attend the MWRA Significant Industrial User (SIU) meetings this week.  As many of you know, the EPA audited the MWRA and its Industrial Pretreatment Program(IPP) back in December 2007.  The MWRA just received the report back and one of the requirements in the report was to change/streamline their

MWRA Rate Increase - Regulation 310 CMR 10.00

regulations.  The MWRA changed some of the terminology surrounding the adjudicatory proceedings(310 CMR 1.00) and clarified the language and provisions surrounding enforcement actions (310 CMR 2.00).  Changes to 310 CMR 10.00 included adding definitions for Best Management Practices(BMP) and New Sources, clarifying the definitions for an SIU, adding a prohibition against BOD and COD that could interfere with the POTW function, and proposing a fee increase over the next three years.  You can view the proposed regulations by visiting http://www.mwra.com/trac/proposedamendments-2009.htm.  The underlined text means an addition, a strike means a deletion.

This fee increase affects ALL industrial users.  If you have a permit, whether it is a low-flow general permit or your are a SIU, your fees will be going up.  The proposed increase is 4.5% each year for three years.  They have not raised their fees since fiscal year 2005 and are looking for feedback regarding the increase.  The informal comment period on the fee increase ends April 24th!  If you have comments regarding the fee increase (or the other regulations changes), please email Carolyn Fiore at cfiore@mwra.state.ma.us by April 24th.

MIT Brain and Cognitive Center Greywater System

Click here to download our PDF brochure of this article at our documents location.

Follow these basic to complete your next successful Greywater System Installation

Successful Greywater projects include the following elements:

1. The project has a favorable Return on Investment (ROI),
2. A wastewater stream characterization was completed,
3. Based on item two, suitable recover and storage equipment was chosen,
4. Based on item two, suitable treatment equipment and piping was chosen, and
5. The system design integrated Plumbing Code & Environmental Regulations including protection, monitoring and regulatory reporting.

Return On Investment
All Greywater projects should have a Return on investment that has a payback of less than two years.  Currently the MWRA Water and Sewer Rates Average  $9.80/HCF (updated Nov 2008, Boston MA Commercial).  A typical Greywater system costs between $50,000.00 and $100,000.00. Based on Boston commercial water and sewer rates, owners need to recycle at least 5,228 gallons of water per day for the system to have a favorable ROI.

Wastewater Stream Characterization
Typical Greywater systems recover water from sources that contain a variety of contaminants that need to be measured to ensure that downstream systems and equipment are not damaged and to prevent exposure of harmful pollutants to the end users.  At a minimum the following measurements are made from a representative stream:

a. Suspended Solids
b. Dissolved Solids
c. Organics (synthetic)
d. pH (Acidity & Alkalinity)
e. Bacteria

Once a baseline analysis is performed further sampling and analysis may be necessary to address site specific contaminants.

Recovery and Storage
Cisterns and Day Tanks need to be configured to minimize contaminant loading and to prevent code violations.  For example, cisterns can be configured to bypass the first portion of rainwater during a rain event to reduce the organic loading on the system caused by bird waste and other debris which may accumulate on the roof.  Second, mixed recovered wastewater streams cannot be discharged to the storm drain and vice versa.  It is illegal to discharge rain water to the sewer system and it is illegal to discharge industrial wastewater to the storm system.

The cistern and day tanks need to be sized appropriately to recover the maximum water amount yet minimize the tank’s footprint. Cisterns should be sized large enough to capture typical rain events and oversized to maximize a rain events’ capture.

Sample Calculation
Cistern volumes can be determined by calculating the roof top water yield for any given rainfall, shown in Equation 1 below.
Day tanks are sized based on the process feeding the Greywater System.  A day tank used to recover Reverse Osmosis Reject (RO Reject) is sized to capture the entire reject cycle.

Equation 1 : V = A2 x R x 0.90 x 7.5 gals./ ft.3
where:

V= volume of cistern (gallons)
A2= surface area roof (square feet)
R= rainfall (feet)
0.90= losses to system (no units)
7.5= conversion factor (gallons per cubic foot)

Example: one 600-gallon Cistern would provide runoff storage from a rooftop area of approximately 2150 square feet for a 0.5 inch (0.042 ft.) of rainfall.

600 gallons = 2150 ft.2 x 0.042 ft. x 0.90 x 7.5 gallons/ft.3

Treatment Equipment & Piping
Based on the wastewater stream characterization study, the Greywater may require some treatment prior to use.  Most systems employ mechanical filtration to remove the suspended dirt to protect downstream equipment such as flush valves.  The type of mechanical filtration equipment will depend on the flow rate.

Typical equipment according for flow rates is:

Multimedia Filtration Systems (flows 50gpm and higher)
Bag Filtration (flows 10gpm to 100gpm)
Cartridge Filtration (flows less than 15gpm)

If needed, treatment to remove or protect the Greywater may include; Bleach, Ozone, or UV Light. The choice is site/wastestream dependent.

Piping planned and installed in new construction projects is critical to meeting the ROI budget as it is almost impossible to retrofit an existing building with separate Greywater Systems.

Regulations require that mixed wastewater is discharged to the appropriate drain system (i.e., storm drains, sanitary drains). Therefore, attention is needed to determine if the cistern overflow piping is directed to storm drainage and if the day tank overflow is directed to sanitary drainage. A regulatory review is needed to ensure that the piping is correct.

Plumbing Code and Environmental Regulations
Currently the Massachusetts Plumbing code requires a State issued special permit for Greywater Systems. All permits are issues by the Board of State Examiners of Plumbers and Gasfitters via the “Special Permission Plumbing Request Application Form.” The Massachusetts Department of Environmental Protection (MADEP) regulates Greywater systems under state regulations 314CMR20.00. The MADEP requires that the water not harm the public who come in contact with the Greywater. Therefore, some Greywater systems may need to add chemicals to kill harmful microorganisms or may need special treatment to remove harmful toxins.

The local Board of Health may also require permitting and monitoring.

As discussed in the August Newsletter, a Fully Automated Industrial Wastewater Pretreatment System will shutdown and temporarily holds wastewater for proper treatment if an out-of-spec condition, an excursion, is detected. These systems require checks only twice a week and an operator on-call. All other systems require a daily operator inspection.

Fortunately, a well designed system requires minimal time and attention to maintain proper function. Maintaining the system safety, chemical inventory, cleaning and calibrating the pH sensor are the most critical daily pH system operator responsibilities. A daily 2-stage active pH Neutralization System daily system check should include:

• Get a general feeling for the system operation. Are there any observable leaks or safety hazards? Is the system louder than normal? Are the pH analyzer/controller currently operating as required?
• Next review the data recorder. Has there been an excursion since the last check? If there has been an excursions system troubleshooting is required.
• Fill out all required paperwork including daily totalized flow and any excursion details (duration and the maximum out-of-spec pH).
• Check the mixers. Are they functioning as expected, or are they hotter or louder than normal? Is the tank agitating sufficiently?
• Check the chemical level in each dispensing drum or day tank. Is there enough chemical, or should more be ordered?
• Ensure the chemical metering pumps are powered and primed. Energize the pumps and use the pH analyzer control to simulate a pH value at which the pumps should respond. Observe the pump injecting chemical into the tank. Does the pH change after exiting the simulation mode?
• Confirm the pH sensors are clean and calibrated to detect changes in pH quickly. Clean the sensors as frequently as required, usually weekly. Check the pH calibration; if the measurement is off calibrate the sensor. A drifting pH reading is a good indication that a pH probe replacement is required.

If this process is followed daily, an Operator can predict when preventive maintenance is needed. If each item on this list is completed daily your pH Neutralization System will always operate as efficiently as it was designed.