English slow sand filters in the sewage plants of Saratov

Once upon a time I happened to be in Saratov. I only had time to visit one site, but it turned out to be well worth it.

The facility I visited is old, and I, like many others, would say that it has great historical value, but apparently the local authorities do not share this opinion. Now let us go back in time, particularly to the second half of the 19th century.

Back then the city of Saratov was constantly developing and its population was pushing 100 000. Construction of an effective water delivery system for firefighting purposes as well as for domestic use was a burning issue.

On June 28th, 1872 the city council signs a contract with a company in order to build a power-operated water delivery system with water intake from the Volga River. The works were to be conducted by “Rachmaninov and Co Partnership” without compensation, with the company keeping the right to operate the system for 20 years after its completion.

The contractor turned out to be rather unreliable and after a few years of standstill passed their obligations on to a third party, who, in their turn, ceded them to the English Joint Stock Company.

The slow sand filter system was first introduced in London by an engineer named Simpson (not Homer) in 1829 in order to purify the water from the river. Almost half a century later that same technology was used to build the sewage plant in Saratov. Starting in 1875, under the supervision of experts from England, a cast iron water pipe system, a water engine and a system of filters were put into operation.

They were installed on one of the slopes of Sokolovaya Hill. The water went through the filters, then into a pressure tank and then to the 15 water outlet booths located all over the city. That was where the locals got their water for domestic use.

The water came from the Volga into this tank, which served as a filter for it. The space inside the tank was filled with clean sand, and after seeping through it the water went through the drain holes and on into the next tank. Naturally, a system of this kind had a number of drawbacks.

First of all, the whole process was rather time-consuming. Secondly, the filters had to be cleaned manually, sometimes up to ten times a year, which required replacing the upper layer of sand that collected all kinds of sediment. Thirdly, the quality of the water left much to be desired.

Today the system is no longer operational, and it is possible to get inside and fully appreciate the elegance of the English-style construction: brick vaults, rounded passages between the sections and tree roots that have penetrated the walls. Right now this place does not evoke any thoughts of pure drinking water. There is some sand left on the floor, but it clearly would not be enough to make a filter.

After passing through the filters the water went into pressure tanks. There were a few of those, and they were built of brick as well, but apparently the brickwork was covered with concrete during the Soviet era. The scale and the size of the structure is undoubtedly very impressive. You can see that water still gets through here; this might be ground water, or maybe it comes from the filters, but the floor is covered in mud which is still wet in places.

The tank consists of three enormous sections that are connected by small passages. Some of them have bridge-like elements of some kind, whose purpose remains unclear to me.

While the filters are equipped with ladders (metal clamps embedded into the walls), the only way to get here is through the hole that you have to climb using whatever you have on hand. A good thing is that the tanks are quite clean, and there are no tags or writings of any kind on the walls.

That is it, thank you for your attention.

Images by Dmitry Solodyankin, reproduced with permission