WASTEWATER TREATMENT IN COFFEE ESTATES

In the year 1996, Mr. Philipose Mathai, IAS, then Chairman of the Coffee Board of India, requested an ex Chairman of the Karnataka State Pollution Control Board to constitute a technical team to visit Coffee plantations in the Coffee growing districts of Karnataka to study coffee pulping operations and recommend a suitable treatment scheme for wastewaters from coffee plantations. The Chairman picked me as the technical expert and two of my associates at that time for good measure to constitute a team.

INDIA COFFEE BOARD HQ- INFANTRY ROAD, BANGALORE

We set out in an Ambassador taxi, the four of us in the month of July to visit several coffee estates, large and small. Two large estates were the focus of our attention The Coffeeland Company Ltd. (CCL) estate in Sakleshpur, Hassan District and the Kelagur Coffee and Tea estates in Chikmagalur District. The visit to the latter Estate was facilitated courtesy Mr. Peter Mathias, Managing partner of the Estate and brother of my dear friend and batchmate from IIT Madras, Paul Mathias.  Paul went on to get his PhD in hardcore Chemical Engineering from MIT, USA, while I went to Vanderbilt to specialize in the slightly less demanding subject of Wastewater treatment. The Kelagur Estate has come a long way since that time, when it was only about 300 odd Acres in extent.

The Managing Director of CCL had made arrangements for our stay at the historic century old Munzerabad Club in Sakleshpur (estd. 1893).  Leaving Bangalore, just after lunch, we planned to reach Sakleshpur by 2000 hrs. in good time for a sundowner and made to order dinner by the celebrated cooks at the club : but that was not to be.

Less than halfway to our destination, the trusty Ambassador developed serious transmission trouble which grounded the car at a hick town called Yediyur (no connection to our own dear ex Chief Minister Yediyurappa) on NH 48, about 100 KM from Bangalore. It took the whole of 2 hours to set right the blasted thing, as we amused ourselves mingling with the local cattle milling around aimlessly in that dusty, godforsaken town. With dusk falling, we rebooted the car and were off towards Hassan and Sakleshpur, in fast enveloping darkness.

At Hassan, a short stop to pick up the famed Hassan “Sauthe” (Cucumber), the fruit full of flesh, sweet and tender. Reached the Munzerabad club around ten o’clock in the night, to wake up the sleeping caretaker and the cooks to cater to the dire needs of thirsty and hungry travel weary guests.

The next morning we were off to the Kelagur Estate in a village called Javali, through twisting, winding narrow lanes via Mudigere and Kottigehara, on bumpy, muddy and slushy tracks, a hallmark of Karnataka roads anywhere at any time of the year, and more so in the monsoon months. We gained our destination after nearly three hours of tortuous but pleasant drive cutting through coffee estates and stretches of forest land, a distance of mere 50 Km.

At Kelagur, we were shown around the vast estate in their Jeep, the terrain rendered soft and slushy due to incessant rains, and fit only for all wheel drive vehicles. Fresh water from a natural spring on the estate was harvested by means of a check dam, providing sufficient irrigation for the plantation year round : there was a tea factory on the estate and a coffee pulping machine, although idle at this time of the year.  Arabica coffee (the superior variety) is harvested between November to December, while Robusta ripens a little later from January to March. We had to be content therefore with a discourse on the coffee bean production process rather than a practical demonstration : but then the production process itself is quite simple, post the harvesting of berries. The true art and science in the production of coffee lies in proper management of the plantation, prevention and control of various pests, management of irrigation at the right times of the year, pruning, harvesting, management of shade trees so essential for retaining moisture in the soil, controlling soil temperature etc. In the peak harvest season, attracting skilled labour becomes the most challenging task, since demand is high in all the estates across the three major coffee growing districts in Karnataka – Coorg, Chikmagalur and Hassan.

THE ESTATES

By Coffee Board estimates, there were nearly 38,000 small growers in Karnataka with holdings of 10 Hectares or less, accounting for nearly 55 % of coffee production in the state, and in absolute terms contributing 85,000 MT of clean coffee to the pool. Robusta coffee was predominantly grown in these smaller estates, being the easier crop to manage with lesser inputs of skills, men and material. The total production of Arabica and Robusta in that year in Karnataka was estimated to be around 160,000 MT, from a total planted area of around 155,000 Hectares. The larges estates, ranging from 200 Acres and over were chiefly in the hands of corporates and a few big family owned enterprises.

THE WASTEWATER

It was estimated that during the peak coffee pulping season between December to March (which unfortunately coincides with the dry season in this part of India), approx. 100,000 cum of day of coffee pulping wastewater would be generated. Typically these discharges find their way into dry or drying rivulets and streams, carrying with them immense pollution potential, without the mitigating effect of dilution waters in the water courses, and posing a real threat to drinking water sources of towns and cities downstream.

At an average  BOD (Biochemical Oxygen Demand) level of 3,000 mg/L, approx. 300 MT of BOD would be released into the environment every day. To put the numbers in perspective, that is the equivalent of the pollution potential from untreated sewage discharged by a city like Bangalore of that day with a population of 5 Million. : only about 3 times over.  I wonder now if somebody in the Coffee Board even read my report : the situation on the ground is not much better now from  reports I read in the newspapers.

THE TREATMENT

All things considered (I was a great fan and avid listener of a talk show by that name on National Public Radio – NPR when I was a student in the USA for its brilliant and objective analysis and presentation of news and events of topical interest), I recommended to the Coffee Board treatment plants of modular design to cater to 10, 20, 40 and 80 KLD of wastewater to suit various users. Basic details on the raw wastewater quantity and quality were furnished by scientists from the Central Coffee Research Institute – CCRI at Balehonnur, who also joined us during our study tour. I also worked out preliminary details for a typical 40 KLD modular treatment plant. In my recommendations were two alternative routes for treatment :

1. Upflow filter followed by activated sludge aerobic treatment
2. Anaerobic lagoon followed by activated sludge aerobic treatment

Design flow                    : 40 KLD 

BOD in wastewater         : 3000 mg/L

Treated water BOD        : 100 mg/L

Total Cost (upflow filter)  : Rs. 925,000

Total cost (An. Lagoon)   : Rs. 775,000

Chemicals                      : Rs. 10,000 per season

Power                            : Rs. 15,000 per season

Area occupied                  : 350 sqm (Upflow filter )

                                         : 600 sqm (An. Lagoon)

The operation of the plant under both alternatives was by design kept fairly simple. Finally, it was recommended that the Coffee Board set up demonstration plants based on the two alternatives to encourage and convince the planters to invest money in protection of their own environment and that of their neighbours and population at large downstream.

I have grave doubts if any of these recommendations have seen the light of day. I only read in the newspapers and reports of the Pollution Control Board that Anaerobic lagoons are in place. Their efficacy and treatment efficiency does bear further scrutiny, knowing fully well the competence of these blokes.

Dr. Ananth S Kodavasal                               First Published : January 02, 2012