WSU Tree Fruit Research & Extension Center

Postharvest Information Network

Monday, May 30, 2016

WSU-TFREC/Postharvest Information Network/The Fresh Fruit Packing General Wastewater Discharge Permit: Compliance Trends and Permit Re-Issuance

The Fresh Fruit Packing General Wastewater Discharge Permit: Compliance Trends and Permit Re-Issuance


There are three main topics of the Fresh Fruit Packing General Wastewater Discharge Permit I would like to cover. The first is a review of the overall industry permit compliance trends over the last three years. The second is an overview of the permit re-issuance process and how you can participate, and the third is a quick look at the proposed changes in the permit.

Permit Compliance
Permit compliance consists of two parts: 1) submittal compliance, which is turning reports in on time and 2) monitoring compliance, which is testing the wastewater to see if it is in compliance with the permit effluent limits.

Overall there was been a significant improvement in submittal compliance in 1997. Sixty-five percent of the 1997 "Yearly Facility Reports" were on time and 82% were in within one week of the deadline. This is up from 70% in 1996. The submittal of monthly "Discharge Monitoring Reports" for surface water discharges also showed improvement. While there are no trends on who is late, there appears to be more late reports during the summer slack season or just after harvest begins when things get busy. It is important to set up a regular routine so even during slack or busy times the reports get done.

Monitoring compliance includes both "non-reporting violations", which is not doing a required test, and "effluent violations", which are those in excess of the permit effluent limit. The total number of monitoring violations, both effluent and non-reporting, has decreased in each of the last 2 years. In 1995 there were 2803 total violations. In 1996 the total dropped 45% to 1545 and in 1997 there another 45% drop to 839.

A substantial portion of this improvement has been due to the reduction in non-reporting violations. However, there are still some opportunities for reducing these violations further. Almost one-half of the non-reporting violations in 1997 were for Flow and pH. Both of these parameters can be determined by the facility and both are required for every wastewater sample.

While there was only a small decrease in actual effluent limit violations in 1997, the large drop in non-reporting violations means that there was a proportional improvement in the effluent limit violations. Once again there are some opportunities for reducing the number of effluent limit violations. Total Residual Chlorine and pH account for 20% of the violations. Both can be done by the facility and are controllable through process adjustment. Total Suspended Solids(TSS) are 15% of the violations and can usually be dealt with effectively with known technologies such as filters, screens, and sedimentation basins. Other types of violations are more site specific and must be dealt with on a case-by-case basis.

Good communication between the facility and Ecology is vital in dealing with effluent violations. Many facilities are starting to put comments on the reports explaining why the violations occurred and what has been done to fix the problem. This is an excellent way to keep me informed of what is going on and also to document that problems are being handled in a timely manner. Also calling me if you have a question or a problem is an excellent idea.

Ecology is also working on getting more compliance information to you. Those of you with surface water discharge may already have received a quarterly Discharge Monitoring Report Compliance Summary. I am working on a similar annual report for the data submitted on the Yearly Facility Reports. The purpose of these summary reports is to give you more timely feedback on how you are doing and what issues you may have to address.

Permit Re-Issuance Process

Wastewater discharge permits, including this general permit, are issued for a period of five years. This permit was issued in March 1994 and will expire in March 1999. Permit re-issuance is a complex process involving Ecology, US EPA, the fresh fruit packing industry, supporting industries such as chemical manufacturers, and the general public. Below is a summary of the major milestones in the re-issuance process.

One key milestone for industry is the deadline to submit an application for coverage under the new permit. A re-application form is currently being developed and will be sent to every current permittee some time this summer. This will give the industry time to complete the form before harvest begins. It is very important that each facility complete this application because without it their permit coverage will terminate when the current permit expires.

Proposed Permit Changes and Issues for Further Research

The first step in the permit re-issuance process was the formation of a workgroup with both Ecology and industry representatives. That workgroup identified a number of issues with the current permit. Below is a summary of how these issues will be addressed, either as proposals for changes in the permit or as areas where further research may be needed.

There are a few things to remember as we discuss proposed changes in the general permit. First no major changes are planned. Basically all of the current effluent limits and permit requirements will stay the same. Second, all the changes being discussed are still in the proposal stage and must go through several review processes, so the final changes may be somewhat different from what is discussed here. Third, any changes that are made to the permit will not go into effect until the new permit is issued in March 1999. Until then the current permit requirements remain in effect.

Proposed Permit Changes
SOPP is a fungicide that is used with float enhancers in pear float dump tanks at concentrations of 1000 to 3000 mg/L. However, the current permit limit for land application and dust abatement is 1000 mg/L. The new permit will keep the 1000 mg/L limit, but by using the maximum application rate of 4840 gallons per acre for wastewater containing 12% ligninsulfonate this limit can be expressed on a mass loading basis. In short this means that as the concentration increases above 1000 mg/L, the maximum application rate goes down proportionally. For example, wastewater containing 2000 mg/L SOPP could be applied at a maximum rate of 2420 gallons per acre. The industry will need to do bioassays to determine the level at which the pear float tank water will designate as a hazardous waste with the various float enhancers. These bioassays will determine the upper concentration limit.

Calcium chloride is used as a post harvest drench at concentrations up to the label rate of 2200 mg/L. This concentration will exceed the current permit effluent limit for chlorides of 250 mg/L. A simplified model was developed to determine the probable dilution that would occur from rainfall. The model resulted in a maximum application rate of 1800 gallons acre year for wastewater containing calcium chloride used at the label rate.

Monitoring will remain basically the same with the following 2 exceptions:

  1. Monitoring frequency of non-contact cooling water (NCCW) to surface waters will be reduced to quarterly. The parameters to be tested will remain the same.

  2. To ensure the narrative criteria that NCCW not contain priority pollutants, dangerous wastes, or toxics in toxic amounts is being attained, a bioassay will be required for all surface water discharges of NCCW with chemical additives. This bioassay will be run once per 5 year permit cycle or if there are changes to the NCCW chemical additives.

All current permittees should already have completed an Environmental Compliance Plan. It will not be necessary to do a new plan. However, the current plan should be reviewed and updated by the time the new permit is issued.

The current permit has somewhat confusing use of the term "On-site systems" in conjunction with the POTW Treatment/Disposal Method. It was never intended to include septic systems with sub-surface drainfields in the general permit. Therefore, all references to "on-site systems" will be removed from the general permit. Any facility discharging to a sub-surface drainfield must apply for coverage under an individual permit.

A process is being developed which may allow the use of chemical and biological fungicides not specified in the permit.

Some other miscellaneous clarification will include expressing flow in gallons per day, enhancing the definitions of the Treatment/Disposal Methods, etc.

Areas for Possible Further Research
Currently, if a facility is unable to meet the permit limits through the use of AKART (All Known, Available, and Reasonable Technologies for the prevention and treatment of pollutants), and they wish to continue to use the land application system, they must apply for coverage under an individual permit and submit an engineering report. The industry has requested that the general permit limits be raised as listed in the table below.

To change the general permit limits an engineering study must be done which will provide scientific evidence that the higher limits will not result in a violation of the water quality standards. This study must cover all potential land application sites in the region covered by the general permit. The industry is considering whether such a study is feasible. If such a study is undertaken it will be a long term project and would not be completed in time for this re-issuance. Therefore, the current process of applying for an individual permit on a site-by-site basis will continue.

Approximately 25 facilities have high Total Dissolved Solids (TDS) in their incoming NCCW water, which is resulting in violations of the TDS limits for land application and percolation systems. This is an area that will require further study to find a solution to this problem. Meanwhile, facilities with this problem should fine tune the number of cycles run while balancing this with water conservation needs, spread the discharge over as great an area as possible, and investigate alternate Treatment/Disposal Methods.

Ligninsulfonate is used as a float enhancer in pear float tanks. While the only allowed Treatment/Disposal Method for the dump tank water is dust abatement, a certain amount of the ligninsulfonate is carried over on the fruit and equipment into the rinse water. Ligninsulfonate has an extremely high BOD and TDS that can result in effluent limit violations. It also has a dark brown color that can disrupt the operation of POTWs using ultraviolet light disinfection systems. Further research is needed to find ways to minimize the ligninsulfonate carryover and to pretreat the rinse water.


In conclusion I would like to say that the compliance trends are very positive. Overall the industry is putting in a good effort and we need to continue to do so to deal with the remaining issues. The permit re-issuance workgroup is an excellent part of this process. Remember to watch for the application form this summer and get it in by the end of August. If you have any input concerning the new permit contact on of the workgroup members and as always, if you have any questions about the permit please contact me.

Steven R. Huber, General Permit Manager

Washington State Department of Ecology, Central Regional Office
15 West Yakima Avenue, Suite 200, Yakima, Washington 98902

14th Annual Postharvest Conference,
Yakima, Washington
March 10-11,  1998

Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us